HomeMy WebLinkAboutItem 6a. Review of Community Forest Plan
TREE COMMITTEE AGENDA REPORT
SUBJECT: CITY OF SAN LUIS OBISPO COMMUNITY FOREST PLAN
RECOMMENDATION
1. Receive a presentation on the City of San Luis Obispo Community Forest Plan; and
2. Recommend that the City Council approve the City of San Luis Obispo Community
Forest Plan.
SITE DATA
Applicant: City of San Luis Obispo
Zoning: Various – Citywide
General Plan: Conservation & Open Space Element; Climate Adaptation & Safety
Element
Site Area: Various - Citywide
Environmental Status: Categorically Exempt from CEQA; no other permits or
entitlements required
1.0 SUMMARY
The project is a Community Forest Plan (CFP) written for the City of San Luis Obispo, as
first identified in the City’s 2020 Climate Action Plan (CAP) for Community Recovery and
CAP Volume III, the 2023-2027 Work Program. The preparation of the CFP is also
identified in the Major City Goal work program for Climate Action, Open Space, and
Sustainable Transportation that is included for the City’s 2021-23 Financial Plan.
The Community Forest Plan is categorically exempt from CEQA under Section 15262,
Feasibility and Planning Studies, as an advisory planning document that has no binding
effect on future activities. As an overarching planning and guidance document that
provides recommendations only, without regulatory authority or entitlement of projects
that can be implemented directly that would have a physical effect on the environment,
the project is also exempt under the General Rule, Section 15061 (b)(3) since it can be
seen with certainty that the Community Forest Plan will not have a significant effect on
the environment.
Meeting Date: 2/27/2023
Item Number: 6a
Time Estimate: 60 minutes
Page 43 of 299
Item 6a
2.0 COMMITTEE PURVIEW
The Tree Committee’s role is to review the project and provide a recommendation to the
City Council, in this case, regarding consistency with the various policies and standards
set forth that are applicable to Urban Forestry, such as the Conservation and Open Space
Element and Climate Adaptation and Safety Element of the General Plan, the Climate
Action Plan for Community Recovery, and San Luis Obispo Municipal Code (SLOMC)
Section 12.24 (Tree Regulations).
3.0 PROJECT DESCRIPTION
The San Luis Obispo Community Forest Plan (CFP) is a collaborative effort between the
City of San Luis Obispo’s Public Works Department and the Office of Sustainability &
Natural Resources, a part of the City Administration Department.
The CFP is based in part on a professional project report completed in 2022 by a graduate
student in Cal Poly San Luis Obispo’s Master of City & Regional Planning program. The
Master’s degree report was based on extensive review of peer -reviewed scientific
literature, City of San Luis Obispo documentation (General Plan, Municipal Code), other
cities’ urban forest management plans, and the 2021 Davey Resource Group
Organizational Assessment report. It was also informed by the results of 11 intervi ews
conducted with knowledgeable, mostly local urban forestry professionals / stakeholders.
The CFP fulfills two needs: (1) it provides a vision for a strengthened and expanded urban
forest, and all the attendant benefits to residents and visitors, after several years of
deferred maintenance; and (2) it comprises part of the City’s climate action planning
efforts through its addressing of the proposal to plant 10,000 trees by 20 35, which should
sequester and store large amounts of carbon that would otherwise enter the atmosphere.
The CFP is specifically called for under Pillar 6 (Natural Solutions) of the 2020 CAP and
its recent update, CAP Volume 3: 2023-27 Work Program.
The goals of the CFP are as follows:
1. Maintain and expand San Luis Obispo’s urban forest to maximize environmental,
social, and economic benefits for all, while minimizing undesirable conditions.
(Maintain/expand forest)
2. Adopt a “right tree, right place,” lifecycle-based perspective towards urban trees
which includes the planting, care, and end -of-life use of climate-ready trees in
locations where they will have the greatest opportunity to thrive .
(Sustainability/climate resilience)
3. Foster a spirit of collaboration between and within City departments that are
involved in urban forest management, as well as between the City and other local
stakeholders (e.g., community groups, nonprofit organizations, businesses,
utilities, other cities, Cal Poly, other State agencies). (Collaboration)
Page 44 of 299
Item 6a
4. Educate and seek the involvement of City residents and visitors, including
historically marginalized groups, in order to obtain their interest and participation
in creation of a thriving urban forest. (Outreach/equity)
The CFP’s objectives are as follows:
Plan Objective Associated
Goal
Objective 1.1: Accrue and Analyze Data All
Objective 1.2: Strengthen Maintenance Practices and Clear the
Backlog
1
Objective 1.3: Increase New Plantings and Implement the 10 Tall
Initiative
All
Objective 1.4: Reexamine Tree Removal and Mitigation Policies 1,3
Objective 1.5a: Focus on Sustainability – Climate Resilience All
Objective 1.5b: Focus on Sustainability – Lifecycle Perspective All
Objective 1.5c: Focus on Sustainability – Soil Enhancement and
Stormwater Management
1
Objective 1.5d: Focus on Sustainability – Safety 1,3,4
Objective 1.5e: Focus on Sustainability – Water Conservation 2,4
Objective 1.6: Address Issues Unique to Downtown All
Objective 1.7: Increase Outreach to Officials and the Public All
Objective 1.8: Focus on Equity 3,4
4.0 ATTACHMENTS
A - City of San Luis Obispo, Draft Community Forest Plan
B - Davey Resource Group, Organizational Assessment Summary Report
C - West Coast Arborists, City of San Luis Obispo Inventory Overview
Page 45 of 299
Page 46 of 299
City of San Luis Obispo Community Forest Plan
Office of Sustainability & Natural Resources – April 2023
Page 47 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 1 of 99
Acknowledgments
City of San Luis Obispo
Community Forest Plan
Adopted
(Month Day, Year)
City Council
Erica A. Stewart, Mayor Jan Marx, Vice Mayor
Andy Pease Michelle Shoresman
Emily Francis
Tree Committee
Richard (Alan) Bate
Henry Bonifas
Daniel Canella
Elizabeth Lucas
Emily Rosten
City Management
Derek Johnson, City Manager
Shelly Stanwyck, Assistant City Manager, Community Services
Greg Hermann, Deputy City Manager
City Staff
Michael Codron, Greg Cruce, Christopher Hamma, Robert Hill,
Matt Horn, Freddy Otte, Lucia Pohlman, Chris Read, Anthony Whipple
Technical Experts, Urban Forestry Stakeholders & Others Who Helped
Mike Boswell, Joe Carotenuti, Ron Combs, Kim Corella, Chris Dicus, Thomas Kessler and SLO
History Center volunteer staff, Jeff Reimer, Matt Ritter, Nathan Slack, Bettina Swigger,
Rodney Thurman, Danny Torres, Matthew Wells, Jenn Yost
City of San Luis Obispo
990 Palm Street
San Luis Obispo, CA 93401
All photos taken by Christopher Hamma unless otherwise noted.
Cover photo: Bishop Peak Natural Reserve
Page 48 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 2 of 99
Table of Contents
Acknowledgments ......................................................................................................................................... 1
Table of Contents .......................................................................................................................................... 2
List of Figures ................................................................................................................................................ 4
List of Acronyms ............................................................................................................................................ 5
I. Vision and Mission Statements ............................................................................................................. 6
A. Vision ............................................................................................................................................. 6
B. Mission .......................................................................................................................................... 6
II. Goals ..................................................................................................................................................... 7
III. Summary of Key Findings .................................................................................................................. 8
IV. Introduction .................................................................................................................................... 10
V. Historical Context ................................................................................................................................ 12
VI. Policy Context/Relationship to Other City Documents ................................................................... 15
A. General Plan ................................................................................................................................ 15
B. Municipal Code ........................................................................................................................... 15
C. Major City Goals .......................................................................................................................... 17
D. Climate Action Plans ................................................................................................................... 17
E. Other Planning Documents ......................................................................................................... 17
F. Urban Forest Services Organizational Assessment and Updated Public Tree Inventory ........... 18
VII. Implementation .............................................................................................................................. 19
A. 10 Tall: An Initiative to Plant 10,000 Trees by 2035 .................................................................. 20
B. Community Forest Plan Implementation Matrix ........................................................................ 21
VIII. Next Steps ....................................................................................................................................... 33
References Cited ......................................................................................................................................... 34
Appendix A: Additional Background Information and Research ............................................................... 42
A. Design and Implement the Program; Accrue and Analyze Data ................................................. 42
1. Davey Resource Group Organizational Assessment Report (2021) ............................................ 42
2. West Coast Arborists Tree Inventory Update (2021-22) ............................................................ 44
3. Urban Forest Ecosystems Institute (UFEI) Data .......................................................................... 45
4. Targets ........................................................................................................................................ 45
5. Metrics ........................................................................................................................................ 46
Page 49 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 3 of 99
6. Data Analysis ............................................................................................................................... 47
B. Strengthen Maintenance Practices and Clear the Backlog ......................................................... 47
C. Increase New Plantings and Implement the 10 Tall Initiative .................................................... 48
D. Reexamine Tree Removal and Mitigation Policies ...................................................................... 50
E. Focus on Sustainability ................................................................................................................ 50
1. Right Tree, Right Place ................................................................................................................ 51
2. Climate Readiness ....................................................................................................................... 53
3. Urban Forest Diversity ................................................................................................................ 54
4. Pests and Disease ........................................................................................................................ 54
5. Lifecycle Perspective ................................................................................................................... 56
6. Soil Enhancement and Stormwater Management...................................................................... 58
7. Safety .......................................................................................................................................... 59
8. Water Conservation .................................................................................................................... 60
F. Address Issues Unique to Downtown ......................................................................................... 61
G. Increase Outreach to Officials and the Public ............................................................................. 62
H. Address Equity Issues .................................................................................................................. 63
Appendix B: City of San Luis Obispo Designated Heritage Trees ............................................................... 65
A. Dawn Redwood, Del Mar Ct. ....................................................................................................... 66
B. Torrey Pine, Casa St. ................................................................................................................... 68
C. Cork Oak, Lincoln St. ................................................................................................................... 70
D. California Bay Laurel, Brizziolari Creek ....................................................................................... 72
E. Coast Redwood, Mission Plaza (“Moon Tree”) ........................................................................... 74
F. Japanese Maple, Jack House & Gardens ..................................................................................... 76
G. Incense Cedar, The Monday Club ............................................................................................... 78
H. Olives, Conejo Ave. ..................................................................................................................... 80
I. Coast Redwood, Higuera St. ........................................................................................................ 82
J. Coast Redwoods, Dallidet Adobe & Gardens .............................................................................. 84
K. Deodar Cedar, Buchon St. ........................................................................................................... 86
L. Western Redbud, Pismo St. ........................................................................................................ 88
M. Shamel Ash, Mitchell Park .......................................................................................................... 90
N. California Sycamore, Old Mission Cemetery, Bridge St. ............................................................. 92
O. Incense Cedars, California Sycamores, Queen Palm – CalTrans District 5 Offices, Higuera St. .. 94
Page 50 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 4 of 99
List of Figures
Figure 1. Roughly 60-year-old Indian laurel fig (Ficus microcarpa) trees along Higuera Street in
downtown San Luis Obispo. .......................................................................................................................... 5
Figure 2. Carrot wood (Cupaniopsis anacardioides) trees along Chorro Street, downtown San Luis
Obispo. .......................................................................................................................................................... 6
Figure 3. A West Coast Arborists crew prunes Brisbane box trees (Lophostemon confertus) along Palm
Street in downtown San Luis Obispo, July 2022. .......................................................................................... 7
Figure 4. The City of San Luis Obispo’s Tree Pruning Zones are based on its Pavement Maintenance
Areas. ............................................................................................................................................................ 9
Figure 5. A partial list of the benefits provided by urban trees. Source: AECOM, 2013............................ 10
Figure 6. San Luis Obispo’s Tree City USA flag. ........................................................................................... 11
Figure 7. Excerpt from Harris and Ward’s 1870 map of downtown San Luis Obispo; the Mission is seen
near the bottom between Broad and Chorro Streets, with the Mission orchard to the north.................. 13
Figure 8. “Higuera Street then and now.” Photo dates unknown. Source: Davey Resource Group Urban
Forestry Organizational Assessment, 2021................................................................................................. 14
Figure 9. A West Coast Arborists crew trims a London plane tree (Platanus × hispanica) in front of the
San Luis Obispo Repertory Theatre, August 2022. ..................................................................................... 16
Figure 10. The City’s Downtown Concept Plan visualizes Downtown SLO as a verdant, highly walkable
destination (City of San Luis Obispo, 2017). ............................................................................................... 18
Figure 11. One of the City’s valued tree planting partners is ECOSLO; volunteers pictured here (ECOSLO,
2022). .......................................................................................................................................................... 20
Figure 12. Murray Avenue’s unique tree-lined pedestrian median, San Luis Obispo. ............................... 33
Figure 13. Terrace Hill and Islay Hill beyond Court Street Plaza in downtown San Luis Obispo. ............... 41
Figure 14. Bishop Peak Natural Reserve. .................................................................................................... 43
Figure 15. Ten most common urban tree species in San Luis Obispo. Source: West Coast Arborists, 2022.
.................................................................................................................................................................... 44
Page 51 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 5 of 99
List of Acronyms
CAP Climate Action Plan
CASE Climate Adaptation and Safety Element
CFP Community Forest Plan
DCP Downtown Concept Plan
DEI Diversity, Equity, and Inclusion
DRG Davey Resource Group
ECOSLO The Environmental Center of San Luis Obispo County
GHG Greenhouse Gas
ISA International Society of Arboriculture
LIDAR Light Detection and Ranging
MPCP Mission Plaza Concept Plan
NAIP National Agriculture Imagery Program
OA Organizational Assessment
SFR Single-Family Residential
SLO San Luis Obispo
UFEI Cal Poly SLO Urban Forest Ecosystems Institute
WCA West Coast Arborists
WUI Wildland-Urban Interface
Note: A list of acronyms specific to the Implementation Matrix is provided in Section VII.
Figure 1. Roughly 60-year-old Indian laurel fig (Ficus microcarpa) trees along Higuera Street in downtown
San Luis Obispo.
Page 52 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 6 of 99
I. Vision and Mission Statements
A. Vision
The City of San Luis Obispo is a community identified and shaded by a diverse urban forest.
Relying on the Community Forest Plan, the City actively encourages participation in tree planting
and stewardship, preserves and protects trees, promotes public safety and tree health,
implements cost-effective enhancement and maintenance of the forest, increases public
awareness of the value of our community forest, and maximizes the social, economic, and
environmental benefits of the urban forest for current residents and future generations.
B. Mission
The mission of the City of San Luis Obispo Community Forest Plan (CFP) is to achieve the stated
Vision by working with and empowering city residents and partners to establish innovative,
science-grounded goals and strategies to protect, expand, and nurture the City’s public tree
cover and the associated benefits over the coming decades.
Figure 2. Carrot wood (Cupaniopsis anacardioides) trees along Chorro Street, downtown San Luis Obispo.
Page 53 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 7 of 99
II. Goals
The goals of the CFP are as follows:
1. Maintain and expand San Luis Obispo’s urban forest to maximize environmental, social,
and economic benefits for all, while minimizing undesirable conditions
(Maintain/expand forest)
2. Adopt a “right tree, right place,” lifecycle-based perspective towards urban trees which
includes the planting, care, and end-of-life use of climate-ready trees in locations where
they will have the greatest opportunity to thrive (Sustainability/climate resilience)
3. Foster a spirit of collaboration between and within City departments that are involved in
urban forest management, as well as between the City and other local stakeholders
(e.g., community groups, nonprofit organizations, businesses, utilities, other cities, Cal
Poly, other State agencies) (Collaboration)
4. Educate and seek the involvement of City residents and visitors, including historically
marginalized groups, in order to obtain their interest and participation in creation of a
thriving urban forest. (Outreach/equity)
Figure 3. A West Coast Arborists crew prunes Brisbane box trees (Lophostemon confertus) along Palm
Street in downtown San Luis Obispo, July 2022.
Page 54 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 8 of 99
III. Summary of Key Findings
This Community Forest Plan (CFP), and the additional
background information provided in Appendix A, are
based on the results of research conducted in 2021 and
2022 regarding the state of San Luis Obispo’s publicly
owned urban forest – primarily street and park trees, as
well as those located at City facilities. City open space and
creek corridor trees are also covered by the plan. The
projected lifespan of the CFP is 2023 – 2035.
The contents of the CFP are based on extensive review of
published urban forestry literature, City of San Luis
Obispo documentation (including the General Plan and
Municipal Code), other cities’ forest management plans,
and consultant reports commissioned by the San Luis
Obispo Public Works Department, as well as nearly a
dozen interviews conducted with knowledgeable urban
forestry stakeholders.
Key plan recommendations for improving the health and
strength of the urban forest, and thus the well-being of
City residents and visitors, include the following:
• Complete an updated public tree inventory
(streets, parks, and City facilities)
• Continue to use contract services for tree pruning
and move toward a proactive, 6-year
maintenance cycle
• Update the City Street Tree List to focus on
climate-resilient species
• Create a tree planting and care plan, and an urban
wood lifecycle plan
• Strengthen social and environmental equity by
assessing and working to enhance tree cover in
disadvantaged communities
• Reexamine compensatory planting requirements
related to development-related tree removals,
and require follow-up monitoring by a City arborist
SLO’s Urban Forest –
Fast Facts (2022)
Number of public street, park,
and City facilities trees:
12,4551 or 12,4962
Number of tree species: At
least 2212
Percent of public street, park,
and City facilities trees in
“good” condition: 90.41
Total value of street, park,
and City facilities trees: over
$39 million1
Total public & private trees
within the urban boundary
(excluding open space):
48,7102
Estimated citywide (public &
private) percent canopy cover
(2012): 13.23
“Reasonable baseline”
percent canopy cover for a
dry western city: 154
Sources:
1 West Coast Arborists, 2022
2 UFEI, no date
3 Nessen, 2012
4 American Forests, 2017
Page 55 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 9 of 99
• Require City arborist review of all development plans
• Implement a comprehensive urban forest database management system that allows for
multiple administrative functions and facilitates internal/external partner access to the
inventory for updating purposes
• Reevaluate the Commemorative Grove program and the role and authority of the Tree
Committee
• Expand engagement with key stakeholders and the community.
Figure 4. The City of San Luis Obispo’s Tree Pruning Zones are based on its Pavement Maintenance Areas.
Page 56 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 10 of 99
IV. Introduction
Urban forests provide a myriad of social, economic, and environmental benefits to a city’s
residents, visitors, and business owners (Nowak, 2016; Janowiak et al., 2021; see Figure 5).
Urban trees and landscaping clean the air (Nowak et al., 2006); reduce flooding, erosion, noise,
and wind (Livesley et al., 2016); cool our buildings through shading and evapotranspiration (Ko,
2018); create wildlife habitat (Strohbach et al., 2013); and fight climate change by storing
greenhouse gases (GHGs) in the form of wood (Nowak and Crane, 2002).
Figure 5. A partial list of the benefits provided by urban trees. Source: AECOM, 2013.
Trees beautify our cities, increase traffic and pedestrian safety (Dumbaugh and Gattis, 2005),
extend pavement life (Burden, 2006), enhance property value and increase business traffic
(Staats and Swain, 2020), increase happiness and social interaction (Kwon et al., 2021), and
reduce crime (Schertz et al., 2021). They encourage us to engage in outdoor recreation,
strengthening our physical and mental health (Pretty et al., 2005). Some trees warrant special
treatment, such as heritage tree designation, because they have outstanding traits or significant
cultural value (Jim, 2017).
These ecosystem services are worth billions of dollars annually to the 83% of Americans who live
in urban areas (University of Michigan Center for Sustainable Studies, 2021). Trees are a good
investment as well – in California, every dollar put into street tree planting and care returns
nearly $6 to its community in ecosystem services and increased property values (McPherson et
al., 2016).
Yet despite growing recognition of the value created by urban forests, the United States is losing
roughly 36 million trees each year due to causes including development, pests and disease,
wildfire, and extreme weather (Nowak and Greenfield, 2018a). San Luis Obispo is not immune to
these trends; until recently the City’s roughly 12,500 public street and park trees suffered from a
Page 57 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 11 of 99
multi-year backlog of deferred maintenance due to staff injuries, retirements, and the effects of
the Covid-19 pandemic.
San Luis Obispo’s residents and officials have long expressed support for a healthy urban forest.
The City is a 39-year participant in the Arbor Day Foundation’s “Tree City USA” program. In
addition, the San Luis Obispo City Council has expressed strong support for the City’s 2020
Climate Action Plan for Community Recovery (2020 CAP) and CAP Volume 3, the 2023-27 Work
Program. The Council also identified protection and expansion of the urban forest as a 2021-
2023 Major City Goal.
Specific actions called for in the City’s CAPs and Major Goals include conducting a new City tree
inventory, revitalizing tree operations and maintenance, planting 10,000 new trees within the
city by 2035 (the 10 Tall Initiative), and writing and adoption of a strategic urban forest plan –
this Community Forest Plan. The CFP is intended to work together with the City’s General Plan,
CAPs, and other guiding documents to support City efforts to become carbon-neutral by 2035
and to adapt to the disruptive effects of a rapidly changing climate.
San Luis Obispo’s publicly owned urban forest contributes greatly to “the SLO life” and the high
level of environmental quality enjoyed by residents and visitors alike. By highlighting the
valuable benefits provided by the City’s urban trees, acknowledging the challenges faced in their
care, and striving to include the public in adaptive management-based forest planning and
activities, it is hoped that this CFP and its future iterations will contribute to enhanced health
and well-being in San Luis Obispo for many years to come.
Figure 6. San Luis Obispo’s Tree City USA flag.
Page 58 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 12 of 99
V. Historical Context
Due to its geographic location and climate, the San Luis Obispo area has historically had
relatively little native tree cover. However, due to the planting of many thousands of non-native
trees in the city over the past two centuries the area now contains far more trees and species
diversity than at any previous time in human history (Seymour, 1986, p. 50).
The Chumash people who occupied what is now the city of San Luis Obispo for over 10,000
years likely lived in a landscape dominated by grassland and chaparral with patchy woodlands of
coast live oak, California bay laurel, toyon, and perhaps a dozen other tree species.
Watercourses were dominated by riparian species such as California sycamore, black and
Fremont cottonwood, and arroyo willow.
The era of Euroamerican settlement and urbanization in the San Luis Obispo area began 250
years ago with the establishment of Mission San Luis Obispo de Tolosa in 1772. The arrival of the
missionaries saw the beginning of landscape conversion to agricultural and eventually urban
uses. Up to half of the area’s native tree cover may have been lost fairly quickly, as there was a
continuous need for heating and cooking fuel as well as building lumber (Carotenuti, 2006).
With the establishment of the Mission, the missionaries began to grow food crops including
olive, fig, pear, grape, and prickly pear cactus, as well as grains and vegetables (see Figure 7).
Olive oil and wine were needed for use in religious ceremonies. In the mid-1830s the missions
were secularized by the Mexican government. Despite the resulting changes experienced by the
residents, Mission San Luis Obispo never ceased being an active church and never fell to
complete ruin as did some of the other missions (Engelhardt, 1933; Carotenuti and Olson, 2004).
By the post-Civil War era, tree planting and creation of park-like landscapes had begun to
capture the fancy of the American public. In San Luis Obispo, local newspapers sang the praises
of urban trees in their pages and lamented the general citywide lack of them, citing their beauty,
their value as sources of “relief and coolness,” and their usefulness as sources of lumber, food,
and medicinal products (e.g., eucalyptus oil).
In fact, the area briefly went through a “timber craze” when blue gum eucalyptus was planted
widely in anticipation of a lumber shortage in California (e.g., San Luis Obispo (Weekly) Tribune,
November 2, 1872, p. 2). Unfortunately for prospective timber barons, blue gum makes a poor
building material due to a tendency to split and warp while drying and the predicted boom
fizzled.
Over the years, hundreds of non-native tree and plant varieties from across the globe were
brought to San Luis Obispo. One notable example is the two rows of camphor trees along Mill
Street between Pepper Street and Johnson Avenue, which were planted in 1912 by D.J. Riley of
Page 59 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 13 of 99
Riley’s Department Store (Zeuschner, 1989). The surviving trees are now 110 years old, make
the block uniquely beautiful, and indeed define the Mill Street Historic District.
Figure 7. Excerpt from Harris and Ward’s 1870 map of downtown San Luis Obispo; the Mission is seen near
the bottom between Broad and Chorro Streets, with the Mission orchard to the north.
Yet, despite many landowners in the city planting trees, San Luis Obispo remained largely
depauperate of greenery for decades, to the extent that new residents and visitors passing
through found it worthy of comment (Fairbanks, 1989). Historical photographs of downtown
San Luis Obispo taken prior to the 1960s show an urban setting that looks utterly desolate in
comparison to its current verdant state (Figure 8).
Starting in the late 1950s, a beautification program initiated by City Councilman R.L. Graves and
City Engineer (later Mayor) Dave Romero led to the green downtown we are familiar with today
(Carotenuti, 2006). Shortly thereafter the segment of Monterey Street in front of the Mission
was torn out and the area was converted into a car-free pedestrian square, creating today’s
Mission Plaza. Beautifying the plaza with landscaping was a high priority for the City, which
moved mature trees from elsewhere in the city to the Plaza, including two old olive trees that
had once been part of the Mission’s olive grove.
Page 60 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 14 of 99
The City became an Arbor Day Foundation “Tree City USA” in 1983 and revived its Heritage Tree
program several years later. Currently, 15 properties within the city host one or more
historically or culturally significant trees (see Appendix B). Perhaps the highest-profile Heritage
Tree in San Luis Obispo at present is the “Moon Tree,” a coast redwood that was planted as a
sapling near Mission Plaza for the national Bicentennial Celebration in 1976, five years after
having visited the moon as a seed aboard Apollo 14 (Sheeler, 2018).
In 1989 the City’s Commemorative Grove was established at Laguna Lake Park. Nine
commemorative trees and 38 windbreak trees were planted for the occasion, with many more
trees having been planted over the intervening years (City of San Luis Obispo, 2022a).
Figure 8. “Higuera Street then and now.” Photo dates unknown. Source: Davey Resource Group Urban
Forestry Organizational Assessment, 2021.
Page 61 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 15 of 99
VI. Policy Context/Relationship to Other City Documents
This Community Forest Plan supports and is supported by existing City of San Luis Obispo goals,
regulations, and policies as set forth in the City’s General Plan, Municipal Code, Major City Goals
for 2021-2023, Climate Action Plans, and other applicable plans, specifications, and standards.
The CFP is also informed by the Davey Resource Group Organizational Assessment Report (2021)
and the West Coast Arborists Urban Tree Inventory Update (2022).
A. General Plan
The Land Use Element (2014), in its Sustainability policies, calls on the City to develop a long-
term tree planting program and recommendations to renew and maintain the urban forest; the
latter includes planting more trees.
The Conservation and Open Space Element (2006) addresses various facets of the urban forest
in its policies relating to Materials, Natural Communities, and Views. Specific requirements
include fostering reuse and recycling of lumber from removed trees; protecting “significant”
trees (including Heritage Trees) and oak woodlands; and creating and maintaining “desired
streetscape characteristics” through the planting and retention of trees, with an emphasis on
California native species.
The Parks and Recreation Plan and General Plan Element Update (2021), also known as the
Parks + Recreation Blueprint for the Future: 2021-2041, calls for shading of play areas in part
through the use of trees, and devotes a section to the selection of appropriate park trees.
The Climate Adaptation and Safety Element Update (CASE; Jan. 2023) combines two State-
required general plan elements: Safety and Environmental Justice. The element addresses
individual natural hazards such as wildfire, flooding, and extreme heat (and related urban forest
concerns) in the overall contexts of climate resilience and diversity, equity, and inclusion (DEI).
The San Luis Obispo County Multi-Jurisdiction Hazard Mitigation Plan is incorporated by
reference into the CASE.
B. Municipal Code
Chapter 12.24 of the San Luis Obispo Municipal Code, Tree Regulations, establishes policies,
regulations, and specifications pertaining to installation, maintenance, and preservation of trees
within the city. Topics include the City Tree Committee, street tree master lists and
management, tree removal, tree protection, heritage trees, enforcement, and appeals, among
others.
Page 62 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 16 of 99
Figure 9. A West Coast Arborists crew trims a London plane tree (Platanus × hispanica) in front of the San
Luis Obispo Repertory Theatre, August 2022.
Page 63 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 17 of 99
C. Major City Goals
In its Major City Goals for the 2021-2023 Financial Plan period, the San Luis Obispo City Council
included the following direction:
• The City will engage in projects and initiatives favoring accrual of the many benefits
provided by trees, including shading and cooling, beautification, habitat, stormwater
retention, and carbon sequestration;
• The City should focus renewed efforts on completing several urban forest-related tasks
that will contribute to the adoption of an integrated, holistic, and equitable approach to
urban forestry.
D. Climate Action Plans
The 2020 Climate Action Plan for Community Recovery (2020 CAP), under “Pillar 6: Natural
Solutions,” called for increased carbon sequestration in the City’s greenbelt and urban forest as
an important component of the City’s path to carbon neutrality by 2035. The 2020 CAP included
the foundational action Natural Solutions 2.1, which directs staff to “Prepare the City’s first
Urban Forest Master Plan by 2021 and plant and maintain 10,000 new trees by 2035.” Detailed
implementation recommendations for this action include updating the tree inventory,
identifying future tree planting opportunities with climate-ready species, and identifying
strategies for ongoing operations and maintenance.
The 2022 CAP update – Climate Action Plan Volume 3: 2023-27 Work Program – was adopted
by the City Council in November 2022. This update continues and expands the strategies
previously identified in the 2020 CAP and includes the FY 2023-25 work program task Natural
Solutions 2.1A, directing staff to “Adopt and implement the Community Forest Plan and make
significant progress on the 10 Tall goal of planting and maintaining 10,000 new trees by 2035.”
E. Other Planning Documents
Urban forest-related matters are further addressed in the following City documents:
• Conservation Guidelines for Open Space Lands (2002) and various Open Space
Conservation Plans
• Waterway Management Plan (2003)
• Community Design Guidelines (2010)
• Downtown Concept Plan (2017)
• Mission Plaza Concept Plan (2017)
Page 64 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 18 of 99
Figure 10. The City’s Downtown Concept Plan visualizes Downtown SLO as a verdant, highly walkable
destination (City of San Luis Obispo, 2017).
F. Urban Forest Services Organizational Assessment and Updated Public Tree Inventory
This Community Forest Plan benefits from an Urban Forest Organizational Assessment (OA)
conducted by Davey Resource Group (DRG; 2021) and an Urban Tree Inventory Update
completed by West Coast Arborists (WCA; 2022).
These efforts were commissioned by the City’s Public Works Department to help address some
of the same urban forestry challenges that have been experienced by cities nationwide in recent
years: declining tree age and species diversity, undesirable effects of climate change (drought-
induced water stress, increased susceptibility to pest and disease attack, damage from extreme
weather events), and reduced staffing levels resulting in significant backlogs of deferred
maintenance.
DRG’s OA summary report contains extensive information and recommendations that informed
the writing of this Community Forest Plan, while WCA’s updated public tree inventory provides a
foundation on which annual work plans and budgets, and thus an effective tree care program,
can be based. Both documents are available to the public on the City’s Trees and Urban Forestry
webpage at https://www.slocity.org/living/natural-resources/trees-and-urban-forestry.
Page 65 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 19 of 99
VII. Implementation
This section summarizes proposed urban forest objectives and actions to be carried out by the
City and its external partners and provides a description of the City’s plan to plant 10,000 new
trees by 2035 – the 10 Tall Initiative. These activities are intended to be informed by the CFP’s
vision, mission, and goals. A full list of proposed actions is provided in Section B, Implementation
Matrix.
CFP Goals Summarized
1. Maintain and expand the urban forest
2. Promote sustainability and climate resilience
3. Pursue internal and external collaboration
4. Perform public outreach and emphasize equity
Involved City Departments
Administration/Diversity, Equity & Inclusion DEI
Administration/Economic Development ECON
Administration/Information Technology IT
Administration/Sustainability & Natural Resources SNR
Community Development CDD
Fire Department FD
Parks & Recreation PR
Public Works PW
Utilities UT
Note: For implementation actions where more than one City Department is identified (see
Section B, Implementation Matrix), an inter-departmental team-based approach is envisioned.
Existing or Potential External City Partners (EXT)
California Polytechnic State University, San Luis Obispo (Cal Poly)
California Department of Transportation (CalTrans), District 5
Coastal San Luis Unified School District
Downtown SLO (Downtown Foresters program)
The Environmental Center of San Luis Obispo County (ECOSLO)
Northern Chumash Tribal Council (NCTC)
One Cool Earth
Pacific Gas & Electric (PG&E)
Rotary de Tolosa
yak titʸu titʸu yak tiłhini Northern Chumash (ytt)
Page 66 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 20 of 99
A. 10 Tall: An Initiative to Plant 10,000 Trees by 2035
In 2019, local stakeholders created the 10 Tall tree planting initiative to raise awareness of the
benefits of urban trees and expand the city’s urban forest. 10 Tall is a City campaign nested in
the 2020 CAP, Pillar Six: Natural Solutions. 10 Tall continued to be a priority area of focus in the
City’s 2022 CAP update (CAP Volume 3, the 2023-2027 Work Program). City staff anticipate that
a large proportion (perhaps 40 percent) of the 10,000 trees proposed for planting will be native
species that will be planted in City open space areas and creek corridors.
A rough estimate of the allocation of tree planting responsibilities under the 10 Tall Initiative
between 2020 and 2035 is shown below.
Responsible Party(ies) Number of Trees Allocated
(Estimate)
City of SLO (Streets, Parks, Open Space, Riparian Areas) 3,000
• Public Works (Streets, Parks, Right-of-Way,
Facilities)
1,000
• Natural Resources & Ranger Services (Creeks,
Open Space)
2,000
Standards for New Development 3,000
Volunteers and External Partners 1,500
Private Residents and Property Owners through
complimentary trees
1,500
Trees planted to date since 2020 CAP (approximate) 1,000
Total 10,000
Figure 11. One of the City’s valued tree planting partners is ECOSLO; volunteers pictured here (ECOSLO,
2022).
Page 67 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 21 of 99
B. Community Forest Plan Implementation Matrix
Action
Number
Action Primary
Associated
Goal(s)
Lead(s) Partners Timeframe
(Near-term,
Mid-term,
Long-term)
Status
(Ongoing,
Expanded,
New)
Objective 1.1: Design and Implement the Program; Accrue and Analyze Data
1.1.1 Ensure Public Works' Urban Forest Services tree
database can incorporate data from the 10 Tall
website into the City's records on a quarterly basis
3,4 PW, SNR IT, EXT Near-term Ongoing
1.1.2 Continue to research and apply for public grant
funding opportunities for the community forest and
urban lumber uses
1,3 PW, SNR EXT Near-term Ongoing
1.1.3 Incorporate urban forestry into the City's existing
Green Team process to ensure interdepartmental
implementation
1,3 PW, SNR CDD, UT,
PR
Near-term Expanded
1.1.4 Identify urban forest targets and metrics 1,4 PW, SNR CDD, EXT Near-term Expanded
1.1.5 Utilize the GIS land cover and equity analysis (tree
cover, impervious surfaces, socioeconomic
characteristics) from the City’s Climate Adaptation
and Safety Element (CASE) to inform tree planting
and care priorities
All SNR, DEI PW, IT,
EXT
Near-term New
1.1.6 Acquire an updated LIDAR dataset for entire City
(public and private trees) for improved canopy
cover and species diversity analysis, as resources
permit
1 IT, SNR PW, EXT Mid-term New
Page 68 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 22 of 99
Action
Number
Action Primary
Associated
Goal(s)
Lead(s) Partners Timeframe
(Near-term,
Mid-term,
Long-term)
Status
(Ongoing,
Expanded,
New)
1.1.7 Collaborate with Cal Poly to conduct a contingent
(nonmarket) valuation study of City right-of-way
trees using i-Tree Eco or equivalent software
1,4 SNR PW, IT,
ECON
Mid-term New
1.1.8 Plan to update the tree inventory every five years 1 PW SNR, EXT Mid-term New
Objective 1.2: Strengthen Maintenance Practices and Clear the Backlog
1.2.1 Continue with expedited pruning by contractors to
catch up on maintenance backlog
1 PW EXT Near-term Ongoing
1.2.2 Ensure that palms and other high-maintenance
species are maintained at recommended intervals
(1-2 years), i.e., more frequently than the regular 5-
year pruning cycle
1 PW − Near-term Ongoing
1.2.3 Conduct annual, or as needed, “windshield surveys”
to identify higher-priority existing or incipient
problems
1 PW − Near-term Expanded
1.2.4 Follow up on every City-required replacement
planting after tree removals
1 PW, CDD EXT Near-term New
Objective 1.3: Increase New Plantings and Implement the 10 Tall Initiative
1.3.1 Maintain existing relationships with external City
partners (and establish new ones) for tree planting,
long-term care (e.g., watering), outreach, provision
of training, etc. across public and private property
in the city
1,3,4 PW, PR,
SNR
EXT Near-term Ongoing
Page 69 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 23 of 99
Action
Number
Action Primary
Associated
Goal(s)
Lead(s) Partners Timeframe
(Near-term,
Mid-term,
Long-term)
Status
(Ongoing,
Expanded,
New)
1.3.2 Implement the 10 Tall goal of planting 10,000 new
trees in the City by 2035 (see also 1.7.6, below)
All PW, SNR,
PR
CDD, EXT Near-term Expanded
1.3.3 Create and implement a detailed, comprehensive
tree planting plan adopting “right tree, right place”
as its guiding principle; specify planting sites and
installation procedures
All PW, SNR,
PR
CDD, EXT Near-term New
1.3.4 Achieve 100 percent stocking of empty street tree
wells (~350 as of 2023) and consider creating new
tree wells based on land cover assessment (see
Action 1.1.5) and equity goals
1,4 PW SNR, DEI
CDD, EXT
Mid-term Expanded
1.3.5 Pilot a City tree and mulch giveaway program if
outreach efforts indicate public interest
1,3,4 PW, SNR UT, EXT Mid-term Expanded
Objective 1.4: Reexamine Tree Removal and Mitigation Policies
1.4.1 Work with the Tree Committee and community to
adopt stronger protections for existing, mature
trees that would be affected by planned new
development
1 PW, CDD − Near-term New
1.4.2 Set a minimum target size(s) for replacement trees
(mitigation planting) that will maximize survival
chances
1,3 PW, CDD EXT Near-term New
1.4.3 Require compensatory planting after tree removal
to match total diameter of mature trees removed,
or another determined metric that ensures that
compensatory tree planting efforts are
commensurate with impacts
1,3 PW, CDD − Mid-term New
Page 70 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 24 of 99
Action
Number
Action Primary
Associated
Goal(s)
Lead(s) Partners Timeframe
(Near-term,
Mid-term,
Long-term)
Status
(Ongoing,
Expanded,
New)
1.4.4 In cases where on-site replanting after private
property tree removal is infeasible, explore the
possibility of compensatory planting in ecologically
appropriate locations, which may include City open
space, parks, or other properties within the city
1 PW, PR,
CDD
SNR Mid-term New
1.4.5 In cases where on-site replanting after private
property tree removal is infeasible, explore the
possibility of modifying regulations to add an in-lieu
fee option with funds to be paid into a formal,
dedicated urban forestry fund
1 PW, CDD SNR Mid-term New
1.4.6 Evaluate modifying City engineering standards for
new development (currently 1 street tree per 35 ft
of sidewalk) with a required number of trees per
dwelling unit (residential), sq. ft. (commercial), or
floors (multistory, all zones)
1,3 PW, CDD Mid-term New
Objective 1.5a: Focus on Sustainability – Climate Resilience (“Right Tree, Right Place”)
1.5a.1 Continue working with external City partners (e.g.,
Cal Poly and interested wholesale growers) to
identify and obtain promising new climate-ready
tree species; update the City's Tree List(s)
accordingly
1,2 PW, EXT SNR, PR,
CDD
Near-term Ongoing
1.5a.2 Monitor overall urban forest health and avoid
planting tree species known to be invasive or highly
susceptible to existing or incipient pests and
disease, to reduce future tree losses
1,2,3 PW, SNR,
EXT
PR Near-term Ongoing
Page 71 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 25 of 99
Action
Number
Action Primary
Associated
Goal(s)
Lead(s) Partners Timeframe
(Near-term,
Mid-term,
Long-term)
Status
(Ongoing,
Expanded,
New)
1.5a.3 Work with contractors and partners to monitor tree
health citywide for new pest and disease outbreaks;
plan for a coordinated, rapid response to threats
1,3 PW, SNR PR, EXT Near-term Ongoing
1.5a.4 Use tree species that are considered suitable for
urban spaces, climate change-ready, and
appropriate for their proposed location and desired
benefits
2 PW, SNR,
PR
CDD, EXT Near-term Expanded
1.5a.5 Plant in locations that maximize long-term tree
health and growth while minimizing potential
conflicts relating to infrastructure and other
concerns
1,2 PW, UT SNR, PR,
CDD
Near-term Expanded
1.5a.6 Focus on planting where canopy cover is lowest to
maximize urban forest benefits (underserved
neighborhoods, parking lots, schoolyards,
transportation corridors)
2 SNR, CDD,
DEI
PW, EXT Near-term Expanded
1.5a.7 Use up-to-date Best Management Practices (BMP)
resources such as “Climate Adaptation Actions for
Urban Forests and Human Health” (Janowiak et al.,
2021) to help guide future City urban forest policy
and actions
All PW, PR,
SNR
CDD Near-term Expanded
1.5a.8 Ensure that open space and riparian plantings use
native tree and shrub species in ecologically
appropriate areas (e.g., oaks are most appropriate
on north-facing slopes and in drainages)
2 SNR, PR EXT Mid-term Expanded
Page 72 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 26 of 99
Action
Number
Action Primary
Associated
Goal(s)
Lead(s) Partners Timeframe
(Near-term,
Mid-term,
Long-term)
Status
(Ongoing,
Expanded,
New)
1.5a.9 Create multiple City tree lists for different locations
(street, park, creek, open space) and tree well sizes
2 PW, SNR,
EXT
PR, CDD Mid-term New
Objective 1.5b: Focus on Sustainability – Lifecycle Perspective
1.5b.1 Prepare a detailed, comprehensive lifecycle plan for
City trees that includes long-term care, replacement
strategies for aging trees, and end-of-life lumber
uses
All SNR, EXT PW, CDD,
PR
Near-term New
1.5b.2 Work with internal and external stakeholders
(businesses and nonprofits) to establish a multi-use
facility that will handle and distribute organic debris
that is too large for the Hitachi-Zosen anaerobic
digester; this "green sort yard" could potentially
host composting, biochar, cellulosic ethanol, and/or
electricity generation uses
2,3 SNR, UT,
EXT
PW, PR,
ECON
Near-term New
1.5b.3 To support the above actions, place roll-off bins at
strategic locations (e.g., tree companies' yards) to
collect the raw material; allow the public to drop off
materials at these locations
2,3 PW, UT,
EXT
SNR Near-term New
1.5b.4 Promote reuse and recycling of, and work to
increase supply of, urban wood waste and lumber
for multiple uses: furniture, small buildings, interior
decoration ("biophilic design"), fencing, artwork,
biogas and biofuels, mulch
All SNR, UT,
EXT
PW, PR Mid-term New
1.5b.5 Set a target requirement for urban wood waste and
lumber to be used in construction or otherwise
2,3,4 SNR, UT,
CDD
EXT Mid-term New
Page 73 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 27 of 99
Action
Number
Action Primary
Associated
Goal(s)
Lead(s) Partners Timeframe
(Near-term,
Mid-term,
Long-term)
Status
(Ongoing,
Expanded,
New)
dedicated to sustainable use within the city, where
feasible (including but not limited to the uses
described above)
1.5b.6 Place a QR code or other mechanism on newly
planted trees to connect the public to educational
information on publicly accessible recycled urban
lumber products (e.g., park benches, fencing,
downtown public art)
4 SNR, UT EXT Mid-term New
1.5b.7 Offer education to industry professionals and the
public on sustainable uses of urban lumber and its
place in the circular, carbon-neutral economy
3,4 SNR, UT,
PW, EXT
- Mid-term New
Objective 1.5c: Focus on Sustainability – Soil Enhancement and Stormwater Management
1.5c.1 Consider the use of technology including
engineered soils, soil cells, permeable hardscape,
and new planter designs, for optimal tree health
and stormwater management outcomes in high-
profile locations with space constraints or poor soils
(e.g., downtown streetscapes) and implement as
appropriate
1 PW EXT Mid-term New
1.5c.2 Evaluate requiring the use of SB 1383-procured
compost in all new plantings and implement as
feasible
1 PW, UT,
SNR
EXT Mid-term New
Objective 1.5d: Focus on Sustainability – Safety
Page 74 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 28 of 99
Action
Number
Action Primary
Associated
Goal(s)
Lead(s) Partners Timeframe
(Near-term,
Mid-term,
Long-term)
Status
(Ongoing,
Expanded,
New)
1.5d.1 Continue to work with CalFire, SLO County, and
other City partners to identify and reduce wildfire
hazards, flooding, hazard trees, and other
vulnerabilities in the city as per the Climate
Adaptation and Safety Element (CASE)
1,3,4 SNR, PW,
FD, PR,
EXT
− Near-term Ongoing
1.5d.2 Continue to monitor and maintain locations within
the City’s creek drainages where flooding could be
exacerbated by fallen trees in the wake of storms,
wildfires, and/or large-scale tree mortality events
1,3,4 SNR, PW,
FD, PR,
EXT
− Near-term Ongoing
Objective 1.5e: Focus on Sustainability – Water Conservation
1.5e.1 Prioritize water conservation in all urban forest-
related actions
2,4 PW, SNR UT Near-term Ongoing
1.5e.2 Require mulching of existing and newly planted
trees; check once a year and supplement if needed
2 PW, SNR UT, EXT Near-term Ongoing
1.5e.3 In City open space areas, plant new trees near
natural drainages where possible
2 SNR, PR EXT Near-term Ongoing
1.5e.4 Work with City partners to perform outreach to
property owners about correct watering of trees
during drought conditions
2,4 PW, UT EXT Near-term Expanded
1.5e.5 Continue to pilot the use of existing or upcoming
water-conserving technologies such as tree bags,
hydrogels, pervious (permeable) hardscape
materials, engineered soils, soil cells, wireless tree
data monitoring, etc.
2 PW EXT Near-term Expanded
Page 75 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 29 of 99
Action
Number
Action Primary
Associated
Goal(s)
Lead(s) Partners Timeframe
(Near-term,
Mid-term,
Long-term)
Status
(Ongoing,
Expanded,
New)
1.5e.6 In hardscape areas, consider redirecting stormwater
runoff to new or existing trees and landscaping as
feasible
2 PW, CDD,
UT
− Mid-term New
Objective 1.6: Address Issues Unique to Downtown
1.6.1 Continue to implement downtown streetscape
improvements as described in the DCP and the
Community Design Guidelines
All PW, CDD SNR, EXT Near-term Ongoing
1.6.2 Continue to work with internal and external City
partners to address tree-related problems affecting
the downtown area to ensure citizen safety,
comfort, and tree health (e.g., evaluation and as-
needed replacement of tree grates; sidewalk
repairs; bird and insect control)
All PW, SNR,
ECON,
CDD
EXT Near-term Ongoing
1.6.3 Continue to support and provide training for the
existing Downtown Foresters volunteer group
1,4 PW, PR EXT Near-term Expanded
1.6.4 Ensure that the proposed urban wood lifecycle plan
(see Objective 1.5b) includes substantial discussion
on downtown's Ficus microcarpa trees, as these are
of high public interest
1,2,4 PW, CDD,
ECON, UT,
SNR
EXT Near-term New
1.6.5 Perform a trial(s) with growth-regulating chemicals
where trees are installed in space-constrained areas
downtown
2 PW CDD, EXT Mid-term New
1.6.6 Support implementation of the City’s Downtown
Concept Plan (DCP) and Mission Plaza Concept Plan
(MPCP)
All PW, CDD,
ECON, PR,
SNR
EXT Long-term Ongoing
Page 76 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 30 of 99
Action
Number
Action Primary
Associated
Goal(s)
Lead(s) Partners Timeframe
(Near-term,
Mid-term,
Long-term)
Status
(Ongoing,
Expanded,
New)
Objective 1.7: Increase Outreach to Officials and the Public
1.7.1 Continue to maintain the City's 39-year long "Tree
City USA" designation
3,4 PW − Near-term Ongoing
1.7.2 Continue to work with external partners to publicize
urban forestry’s importance in climate action and
natural resources management, emphasizing long-
term urban forest care and health over merely
“planting trees”
2,3,4 SNR, EXT PW Near-term Ongoing
1.7.3 Tie in urban forestry outreach with other City
marketing or tourism-oriented programs (e.g.,
“Keys for Trees”)
3,4 PW, SNR,
ECON
EXT Near-term Ongoing
1.7.4 Update the City’s urban forest website: add
pruning schedules; create a publicly viewable,
interactive online map of all City-owned trees; add
photos and descriptions of Heritage Trees; add
discussion of ecosystem services values
3,4 PW, SNR,
IT
- Near-term Expanded
1.7.5 Use more storytelling in urban forestry public
engagement: honor volunteers, partners, and
sponsors in annual or semiannual outreach events
and/or with tree tags or plaques
3,4 PW, SNR,
PR
EXT Near-term Expanded
1.7.6 Support development of the 10 Tall Initiative
website; go live with it by the beginning of FY 2023-
24
3,4 SNR, PW EXT, IT Near-term New
Page 77 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 31 of 99
Action
Number
Action Primary
Associated
Goal(s)
Lead(s) Partners Timeframe
(Near-term,
Mid-term,
Long-term)
Status
(Ongoing,
Expanded,
New)
1.7.7 Create an interpretive and/or commemorative
plaque program for street, park, and Heritage trees
3,4 PW,
ECON,
SNR, PR
EXT Mid-term Expanded
1.7.8 Attract statewide or national urban forestry
conferences to San Luis Obispo
3,4 PW, SNR,
ECON
EXT Mid-term Expanded
1.7.9 Explore initiating a program to provide financial
support to income-qualifying private landowners
for needed care and maintenance of their trees
1,3,4 PW, CDD,
DEI
EXT Mid-term New
1.7.10 Work with City partners to create an “urban
forestry community outreach week,” possibly
combined with the City's annual Earth Day or Arbor
Day celebrations
3,4 PW, SNR,
PR, EXT
- Mid-term New
1.7.11 Approach Cal Poly and/or Cuesta College to create a
new student urban forest steward club or program
(possibly including a tree nursery) that would work
with the City
3,4 SNR, EXT − Mid-term New
1.7.12 Restart the City Commemorative Tree program
when staffing and new, additional site locations
become adequate
1,4 PW − Long-term Expanded
Objective 1.8: Address Equity Issues
1.8.1 Continue to conduct City outreach in, at a
minimum, English and Spanish; consider additional
languages as well, if deemed warranted based on
Census or other demographic data and indicators
4 PW, SNR,
DEI
EXT Near-term Ongoing
Page 78 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 32 of 99
Action
Number
Action Primary
Associated
Goal(s)
Lead(s) Partners Timeframe
(Near-term,
Mid-term,
Long-term)
Status
(Ongoing,
Expanded,
New)
1.8.2 When planning tree planting activities, prioritize
and perform outreach in areas of the City identified
as low-income, vulnerable to heat stress, and in
tree-poor areas where residents express interest in
new trees (see also Objective 1.1)
3,4 PW, SNR,
PR, DEI
PR, IT Near-term Expanded
1.8.3 Coordinate regularly with the City’s DEI Manager,
local indigenous leaders, and other external equity-
focused partners on tree planting activities
3,4 SNR, DEI PW, PR,
EXT
Near-term Expanded
Page 79 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 33 of 99
VIII. Next Steps
Upon adoption of the CFP by the City Council, the most pressing actions will be moving forward
with the hiring of new City urban forest staff and continuing to work with City partners to
implement the 10 Tall Initiative to plant 10,000 new trees by 2035. Other high priorities include
looking into new sources of urban forest funding, creating an urban tree and lumber lifecycle
plan, and continuing to oversee the City’s contractors as they catch up on the City’s tree
maintenance backlog.
Figure 12. Murray Avenue’s unique tree-lined pedestrian median, San Luis Obispo.
Page 80 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 34 of 99
References Cited
AECOM. (2013, December). Financing San Francisco’s urban forest: the benefits + costs of a
comprehensive municipal street tree program. Retrieved from:
https://default.sfplanning.org/plans-and-programs/planning-for-the-city/urban-forest-
plan/UFP_Street_Tree_Report_FINAL_Dec_2013.pdf
American Forests. (2022). Tree Equity Score. Retrieved from:
https://www.americanforests.org/tools-research-reports-and-guides/tree-equity-score/
Andrews, M. (No date). Heritage Trees: City of San Luis Obispo, California. Retrieved from:
https://storymaps.arcgis.com/stories/fbc1b607a9454c66b4fc643518bfc1df
Arbor Day Foundation. (2022). Tree City USA. Retrieved from:
https://www.arborday.org/programs/treeCityUSA/index.cfm?msclkid=532dfb1fb13211eca8855
5e5e54c800c#standardsSection
Buffalo, S. (2016, October 29). Dead trees beget new life. San Luis Obispo Tribune (Bizz Buzz
Extra), pp. 39-42.
Burden, D. (2006). 22 benefits of urban street trees. Glatting Jackson, Walkable Communities,
Inc. Retrieved from: https://ucanr.edu/sites/sjcoeh/files/74156.pdf
California Oak Mortality Task Force. (2021). What is Sudden Oak Death? Retrieved from:
https://www.suddenoakdeath.org/about-sudden-oak-death/
CAL FIRE. (2020). 2019-2020 CAL FIRE Urban and Community Forestry Grant Awards by Project
Category. Retrieved from: https://www.fire.ca.gov/media/11017/19_20-cci-ucf-grant-awards-
final-060320.pdf
CalRecycle. (2022a). California’s Short-Lived Climate Pollutant Reduction Strategy. Retrieved
from: https://calrecycle.ca.gov/Organics/SLCP/
CalRecycle. (2022b). Jurisdiction Procurement Targets Based on January 1, 2021 Population
Estimates. Retrieved from: https://www2.calrecycle.ca.gov/Docs/Web/119889
CalRecycle. (2022c). Urban wood waste. Retrieved from:
https://calrecycle.ca.gov/condemo/wood/
Carotenuti, J. and Olson, T. (2004). Mission San Luis Obispo de Tolosa.
Page 81 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 35 of 99
Carotenuti, J. (2006, April). The Trees of San Luis Obispo. SLO County Journal, pp. 14-15.
Churkina, G., Kuik, F., Bonn, B., Lauer, A., Grote, R., Tomiak, K., & Butler, T. M. (2017). Effect of
VOC emissions from vegetation on air quality in Berlin during a heatwave. Environmental Science
& Technology, 51(11), 6120-6130.
City of San Luis Obispo. (2022a). Commemorative Grove Program. Retrieved from:
https://www.slocity.org/government/department-directory/public-works/programs-and-
services/trees-and-urban-forestry/commemorative-grove
City of San Luis Obispo. (2017, September). Downtown Concept Plan. Retrieved from:
https://www.slocity.org/government/department-directory/community-development/planning-
zoning/specific-area-plans/downtown
City of San Luis Obispo. (2022b). Recycled Water. Retrieved from:
https://www.slocity.org/government/department-directory/utilities-department/water/water-
sources/recycled-water
Conway, T. M., & Bang, E. (2014). Willing partners? Residential support for municipal urban
forestry policies. Urban forestry & urban greening, 13(2), 234-243.
County of San Luis Obispo. (2019, October). San Luis Obispo County Multi-Jurisdictional Hazard
Mitigation Plan. Retrieved from: https://www.slocounty.ca.gov/Departments/Planning-
Building/Forms-Documents/Plans-and-Elements/Elements/Local-Hazard-Mitigation-Plan/San-
Luis-Obispo-County-Multi-Jurisdictional-Hazard.pdf
Davey Resource Group, Inc. (2021). San Luis Obispo Summary Report: Urban Forestry
Organizational Assessment.
Deeproot Green Infrastructure. (2022b). Tree Cover % — How Does Your City Measure Up?
Retrieved from: https://www.deeproot.com/blog/blog-entries/tree-cover-how-does-your-city-
measure-up/
Denig, B.R. (2015). CU-Structural Soil® - A Comprehensive Guide. Retrieved from:
www.hort.cornell.edu/uhi/outreach/pdfs/CU-Structural Soil - A Comprehensive Guide.pdf
Dumbaugh, E., & Gattis, J. L. (2005). Safe streets, livable streets. Journal of the American
Planning Association, 71(3), 283-300.
Page 82 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 36 of 99
Eisenman, T. S., Flanders, T., Harper, R. W., Hauer, R. J., & Lieberknecht, K. (2021). Traits of a
bloom: a nationwide survey of US urban tree planting initiatives (TPIs). Urban Forestry & Urban
Greening, 61, 127006.
Engelhardt, Z. (1933). Mission San Luis Obispo in the Valley of the Bears. Mission Santa Barbara,
Santa Barbara, CA.
Eskalen, A. and Lynch, S. (2017, November 30). Op-Ed: The shot hole borer beetle could kill 38%
of all trees in the L.A. region. Retrieved from: https://www.latimes.com/opinion/op-ed/la-oe-
eskalen-lynch-beetle-killing-southern-california-trees-20171130-
story.html#:~:text=According%20to%20a%20U.S.%20Forest,trees%20in%20the%20urban%20re
gion.
Fairbanks, A. (1989, March 3). The Greening of San Luis Obispo (including “Public invited to plant
memorial trees at park”). San Luis Obispo Telegram-Tribune, p. A-1.
Gleick, P. H., Cooley, H., Poole, K., & Osann, E. (2014). The Untapped Potential of California’s
Water Supply: Efficiency, Reuse, and Stormwater. Pacific Institute and NRDC. Retrieved from:
https://pacinst.org/wp-content/uploads/2014/06/ca-water-capstone-1.pdf
Gordon, L. (1996, March 13). Ficus’ shady reputation prompts change in scenery. Retrieved
from: https://www.latimes.com/archives/la-xpm-1996-03-13-mn-46502-story.html
Hawken, P. (2017). Drawdown: The most comprehensive plan ever proposed to reverse global
warming.
Heynen, N., Perkins, H. A., & Roy, P. (2006). The political ecology of uneven urban green space:
The impact of political economy on race and ethnicity in producing environmental inequality in
Milwaukee. Urban Affairs Review, 42(1), 3-25.
Hilbert, D. R., Roman, L. A., Koeser, A. K., Vogt, J., & van Doorn, N. S. (2019). Urban tree
mortality: a literature review. Arboriculture & Urban Forestry, 45(5). Retrieved from:
https://www.fs.usda.gov/nrs/pubs/jrnl/2019/nrs_2019_hilbert_001.pdf
Hitachi Zosen Inova AG. (2021). San Luis Obispo, USA. Retrieved from: https://www.hz-
inova.com/projects/san-luis-obispo-usa/
Janowiak, M. K., Brandt, L. A., Wolf, K. L., Brady, M., Darling, L., Lewis, A. D., ... & Swanston, C.
W. (2021). Climate adaptation actions for urban forests and human health. Gen. Tech. Rep. NRS-
203. Madison, WI: US Department of Agriculture, Forest Service, Northern Research
Station., 203. Retrieved from: https://www.fs.fed.us/nrs/pubs/gtr/gtr_nrs203.pdf
Page 83 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 37 of 99
Jim, C. Y. (2017). Urban heritage trees: Natural-cultural significance informing management and
conservation. In Greening Cities (pp. 279-305). Springer, Singapore.
Kwon, O. H., Hong, I., Yang, J., Wohn, D. Y., Jung, W. S., & Cha, M. (2021). Urban green space and
happiness in developed countries. EPJ data science, 10(1), 28.
Landry, S. M., & Chakraborty, J. (2009). Street trees and equity: evaluating the spatial
distribution of an urban amenity. Environment and Planning a, 41(11), 2651-2670.
Lawrence, A. B., Escobedo, F. J., Staudhammer, C. L., & Zipperer, W. (2012). Analyzing growth
and mortality in a subtropical urban forest ecosystem. Landscape and Urban Planning, 104(1),
85-94.
Livesley, S. J., McPherson, E. G., & Calfapietra, C. (2016). The urban forest and ecosystem
services: impact on urban water, heat, and pollution cycles at the tree, street, and city
scale. Journal of Environmental Quality. 45: 119-124, 45, 119-124.
Locke, D. H., Hall, B., Grove, J. M., Pickett, S. T., Ogden, L. A., Aoki, C., ... & O’Neil-Dunne, J. P.
(2021). Residential housing segregation and urban tree canopy in 37 US Cities. npj urban
sustainability, 1(1), 1-9.
Magurran, A. E. (1988). Ecological diversity and its measurement. Princeton university press.
Retrieved from:
https://books.google.com/books?hl=en&lr=&id=CuU9DwAAQBAJ&oi=fnd&pg=PP9&dq=ecologic
al+diversity&ots=WBZeV6DIF6&sig=VJRH3RHBXpV3dlyZxOg39Q7QPns#v=onepage&q=ecologica
l%20diversity&f=false
Mandel, K. (2021, February 5). Planting Trees Sounds Like a Simple Climate Fix. It's Anything But.
Retrieved from: https://www.huffpost.com/entry/planting-trees-not-simple-climate-
fix_n_601c1627c5b6c0af54d17e98
McPherson, E. G., Berry, A., van Doorn, N., Downer, J., Hartin, J., Harver, D., & Teach, E. (2020).
Climate-ready tree study: update for Southern California communities. Western Arborist, 12-18.
Retrieved from:
https://www.fs.fed.us/psw/publications/vandoorn/psw_2019_vandoorn002_mcpherson.pdf
McPherson, E. G., & Berry, A. M. (2015). Climate-ready urban trees for Central Valley cities.
Western Arborist, 41(1), 58-62.
Page 84 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 38 of 99
McPherson, E. G., Berry, A. M., & van Doorn, N. S. (2018). Performance testing to identify
climate-ready trees. Urban Forestry & Urban Greening, 29, 28-39.
McPherson, E. G., van Doorn, N., & de Goede, J. (2016). Structure, function and value of street
trees in California, USA. Urban forestry & urban greening, 17, 104-115.
McPherson, E. G., Xiao, Q., van Doorn, N. S., de Goede, J., Bjorkman, J., Hollander, A., ... &
Thorne, J. H. (2017). The structure, function and value of urban forests in California
communities. Urban Forestry & Urban Greening, 28, 43-53.
Nessen, K. 2012. Estimating urban canopy cover in San Luis Obispo. PDF power point
presentation.
Nowak, D. J., Crane, D. E., & Stevens, J. C. (2006). Air pollution removal by urban trees and
shrubs in the United States. Urban forestry & urban greening, 4(3-4), 115-123.
Nowak, D. J., Greenfield, E. J., & Ash, R. M. (2019). Annual biomass loss and potential value of
urban tree waste in the United States. Urban Forestry & Urban Greening, 46, 126469.
Nowak, D. J., & Crane, D. E. (2002). Carbon storage and sequestration by urban trees in the
USA. Environmental pollution, 116(3), 381-389.
Nowak, D. J., & Greenfield, E. J. (2018a). Declining urban and community tree cover in the
United States. Urban forestry & urban greening, 32, 32-55.
Nowak, D. (2016). Urban forests. In: Robertson, G.; Mason, A., eds. Assessing the sustainability
of agricultural and urban forests in the United States. USDA Forest Service FS-1067, Washington,
DC: 37-52., 37-52.
Pretty, J., Peacock, J., Sellens, M., & Griffin, M. (2005). The mental and physical health outcomes
of green exercise. International journal of environmental health research, 15(5), 319-337.
Robertson, G., & Mason, A. (2016). Assessing the sustainability of agricultural and urban forests
in the United States. USDA Forest Service FS-1067, 75 pp., (FS-1067). Retrieved from:
https://www.fs.fed.us/research/publications/FS-1067SustainabilityAgUrb.pdf
Roman, L. A., & Scatena, F. N. (2011). Street tree survival rates: Meta-analysis of previous
studies and application to a field survey in Philadelphia, PA, USA. Urban Forestry & Urban
Greening, 10(4), 269-274.
Page 85 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 39 of 99
Santamour Jr, F. S. (2004). Trees for urban planting: diversity, uniformity, and common sense. C.
Elevitch, The Overstory Book: Cultivating connections with trees, 396-399.
Schertz, K. E., Saxon, J., Cardenas-Iniguez, C., Bettencourt, L., Ding, Y., Hoffmann, H., & Berman,
M. G. (2021). Neighborhood street activity and greenspace usage uniquely contribute to
predicting crime. Npj Urban Sustainability, 1(1), 1-10.
SelecTree. UFEI. (1995-2022). Ficus microcarpa tree record. Cal Poly State University, San Luis
Obispo. Retrieved from: https://selectree.calpoly.edu/tree-detail/609
Seymour, B. (1986). Portrait of a Place: San Luis Obispo. Garden Creek Publications.
Sheeler, A. (2018, August 12). A tree in SLO County had an out-of-this-world beginning. San Luis
Obispo Tribune, p. 1F.
Smith, I. A., Dearborn, V. K., & Hutyra, L. R. (2019). Live fast, die young: Accelerated growth,
mortality, and turnover in street trees. PloS one, 14(5), e0215846.
Staats, H., & Swain, R. (2020). Cars, trees, and house prices: Evaluation of the residential
environment as a function of numbers of cars and trees in the street. Urban Forestry & Urban
Greening, 47, 126554.
Strohbach, M. W., Lerman, S. B., & Warren, P. S. (2013). Are small greening areas enhancing bird
diversity? Insights from community-driven greening projects in Boston. Landscape and Urban
Planning, 114, 69-79.
Treeequityscore.org. (2022). Tree Equity Score for San Luis Obispo, CA. Retrieved from:
https://treeequityscore.org/map/#12/35.28536/-120.66367
UC Riverside Center of Invasive Species Research. (2022). Sudden Oak Death. Retrieved from:
https://cisr.ucr.edu/invasive-species/sudden-oak-
death#:~:text=It%20is%20estimated%20that%20the,soil%20formation%2C%20and%20erosion%
20prevention.
University of Michigan, Center for Sustainable Studies. (2021). Built Environments Factsheet:
U.S. cities. Retrieved from: https://css.umich.edu/sites/default/files/U.S.%20Cities_CSS09-
06_e2021.pdf
Urban Forest Ecosystems Institute (UFEI). (n.d.) Welcome to UFEI: Urban Forest Ecosystems
Institute at Cal Poly. Retrieved from: https://ufei.calpoly.edu/
Page 86 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 40 of 99
USDA Forest Service, Center for Urban Forest Research, Pacific Southwest Research Station,
Davis, California and the Southern Center for Urban Forestry Research & Information, Southern
Research Station, Athens, Georgia. (2004). The large-tree argument: The case for large-stature
trees vs. small-stature trees. Retrieved from:
https://www.fs.fed.us/psw/topics/urban_forestry/products/cufr_511_large_tree_argument.pdf
USDA Forest Service, Region 5 (no date). Urban tree canopy in California. Retrieved from:
https://www.fs.usda.gov/detailfull/r5/communityforests/?cid=fseprd647442
West Coast Arborists. (2022, June 15). City of San Luis Obispo Inventory Overview.
Wilson, B. (2020). Urban heat management and the legacy of redlining. Journal of the American
Planning Association, 86(4), 443-457.
Zeuschner, L. (1989, September 23-24). Mill Street’s in love with leaves. San Luis Obispo
Telegram-Tribune, p.1.
Ziska, L. H., Makra, L., Harry, S. K., Bruffaerts, N., Hendrickx, M., Coates, F., ... & Crimmins, A. R.
(2019). Temperature-related changes in airborne allergenic pollen abundance and seasonality
across the northern hemisphere: a retrospective data analysis. The Lancet Planetary
Health, 3(3), e124-e131.
Page 87 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 41 of 99
Figure 13. Terrace Hill and Islay Hill beyond Court Street Plaza in downtown San Luis Obispo.
Page 88 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 42 of 99
Appendix A: Additional Background Information and Research
The following information is intended to provide additional detail and discussion around some
of the major issues identified by the CFP and serves as the basis for the recommendations in the
CFP.
1. Design and Implement the Program; Accrue and Analyze Data
a. Davey Resource Group – Organizational Assessment Report (2021)
b. West Coast Arborists – Tree Inventory Update (2022)
c. Urban Forest Ecosystems Institute (UFEI) Data
d. Targets
e. Metrics
f. Data Analysis
2. Strengthen Maintenance Practices and Clear the Backlog
3. Increase New Plantings and Implement the 10 Tall Initiative
4. Reexamine Tree Removal and Mitigation Policies
5. Focus on Sustainability
a. Right Tree, Right Place
b. Climate Readiness
c. Urban Forest Diversity
d. Pests and Disease
e. Lifecycle Perspective
f. Soil Enhancement and Stormwater Management
g. Safety
h. Water Conservation
6. Address Issues Unique to Downtown
7. Increase Outreach to Officials and the Public
8. Address Equity Issues
Additional information included in this section was provided by Cal Poly San Luis Obispo’s Urban
Forest Ecosystem Institute (UFEI).
A. Design and Implement the Program; Accrue and Analyze Data
1. Davey Resource Group Organizational Assessment Report (2021)
DRG reviewed the structure and operations, background documents, and existing policies of the
City’s Urban Forest Services program, which is housed in Public Works. They also engaged key
partners and community members, including conducting an online survey to gauge community
awareness and support for the urban forest.
Page 89 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 43 of 99
DRG’s findings were summarized in a 145-page OA
report that included approximately 150
recommendations in the categories of Urban Forest
Resource, Operations and Programs, Urban Forest
Partners, and Organizational Structure and Staffing.
Additional discussion centered on Policy and Regulation,
the Benchmark Community Survey, and Analysis of
Sustainability Indicators.
Some of the OA’s more significant recommendations for
improving the health and strength of the urban forest,
and therefore of City residents and visitors, included:
• Complete an updated public tree inventory (streets, parks, and City facilities)
• Continue to use contract services for tree pruning; move toward a proactive, 6-year
maintenance cycle
• Update the City Street Tree List to focus on climate-resilient species
• Create a tree planting and care plan as well as an urban wood lifecycle plan
• Strengthen social and environmental justice by assessing and improving tree canopy
cover in disadvantaged communities
• Reexamine compensatory planting requirements regarding development-related tree
removals, and require follow-up monitoring by a City arborist
• Require arborist review of all development plans
• Implement a comprehensive urban forest management system that allows for multiple
administrative functions and facilitates internal/external partner access to the inventory
database
• Reevaluate the Commemorative Grove program and the role and authority of the Tree
Committee
• Expand engagement with key stakeholders and the community.
Figure 14. Bishop Peak Natural Reserve.
The DRG Organizational
Assessment report “documents
and benchmarks current
conditions, challenges, and
opportunities, and provides
initial recommendations for the
advancement of the urban
forestry program and the
development of [the Community
Forest Plan].” – Davey Resource
Group, 2021.
Page 90 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 44 of 99
2. West Coast Arborists Tree Inventory Update (2021-22)
The urban forest inventory update conducted by WCA was
another important step in moving forward with efforts to
protect, strengthen, and expand the City-owned portion of
SLO’s urban forest. Urban forest planning and budgeting
efforts achieve the best outcomes when they are based on
complete and up-to-date information.
WCA inventoried 12,455 trees in the City’s public right-of-way
(streets, parks, and City facilities). Address, species, diameter,
height, condition, and other data were gathered for each tree.
In their summary report, WCA estimated the total value of
these trees at over $39 million (West Coast Arborists, 2022).
90.4 percent of the inventoried trees were characterized as being in good condition, with
another 4.2% being considered fair. Approximately two-thirds of the inventoried trees were 12
inches or less in diameter (measured at 4.5 feet above the ground) and were under 30 feet tall.
The 10 most common species and their estimated value are shown in Figure 15:
Figure 15. Ten most common urban tree species in San Luis Obispo. Source: West Coast Arborists, 2022.
Based on their inventory findings, WCA made several recommendations which broadly match
recommendations provided in the DRG OA:
• Establish a grid trimming schedule to prune all trees on a routine cycle (most agencies
average 3 to 5 years per cycle)
• Initiate inspection and mitigation for trees identified at risk of disease or decline
“Knowing the quantities,
locations, species types, and
health conditions of these
essential assets within the
community provides the
foundation for which annual
work plans and budgets are
based. Therefore, having an
inventory is critical to the
implementation of an effective
tree care program.” – WCA,
2022.
Page 91 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 45 of 99
• Create a tree removal plan
• Create a planting plan to fill vacant sites
• Provide young tree maintenance to ensure proper establishment.
3. Urban Forest Ecosystems Institute (UFEI) Data
Cal Poly’s Urban Forest Ecosystems Institute (UFEI) (https://ufei.calpoly.edu/) maintains a
statewide street tree inventory database based on data provided by California’s largest tree
companies (UFEI, n.d.). For San Luis Obispo, this inventory shows a current tally of 12,496 trees
encompassing at least 221 species. This number of trees tracks closely with WCA’s inventory of
12,455 street, park, and City facility trees.
UFEI is also host to an image-processing tool called the Urban Tree Detector. Recent UFEI
research used this artificial neural network-based algorithm to process aerial photography from
the National Agriculture Imagery Program (NAIP), resulting in an estimate of 48,710 trees (public
and private) within San Luis Obispo’s urban boundary as of 2020. This figure is likely an
underestimate for the city as a whole, as it does not include areas of dense closed canopy such
as oak woodlands within City open space areas.
4. Targets
Targets can be thought of as goals or desired future conditions. Currently identified targets for
San Luis Obispo’s urban forest include the following:
• Plant 10,000 new urban trees in San Luis Obispo by 2035
• Reduce annual greenhouse gas (GHG) emissions by 1,490 metric tons of carbon dioxide
equivalent (MTCO2E) in 2035.
Potential urban forest targets may include:
• Plant a certain number of new trees per given time period (e.g., year, two-year Financial
Planning timeframe)
• Plant a certain number of new trees per given geographic area (e.g., square
kilometer/mile, pavement maintenance area, neighborhood, special-status area [e.g.,
low-income])
• Attain 100% City tree well stocking
• Attain 100% replacement of other City trees that were previously removed (e.g., in
parks)
• Attain a specified percent tree canopy cover for the City as a whole or by geographic
area, including privately owned trees (refer below to “Metrics” for further discussion on
percent canopy cover)
Page 92 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 46 of 99
• Prune/mulch a specified number of trees per year
• Sequester a specified annual rate of MTCO2E per year
• Attain a specified total carbon storage amount (MTCO2E) in the City’s trees
• Designate primary- and secondary-priority species of City-owned trees for each City
block, street segment, and/or neighborhood
• Produce neighborhood-level tree maps and make them publicly available online, similar
to the City of Santa Monica
• Attain a given, high percentage of “climate-ready” (resilient to the projected effects of
climate change), City-owned trees across the city or by geographic area
• Achieve a certain dollar value(s) in specified ecosystem services, as determined by
nonmarket (contingent) valuation studies.
5. Metrics
Metrics are measures of progress. They can be used to obtain a one-time “snapshot” of current
conditions but are more useful when measurements are taken repeatedly over time, allowing
for observation of trends that can guide management actions.
Potential urban forest metrics, measured by neighborhood and/or on a citywide basis, could
include the following examples. Some of these would necessarily be estimates:
• % tree well stocking
• % potential park tree stocking
• % survival of newly planted trees at x years (1, 5, 10, 20…)
• % canopy cover
• Species composition/diversity
• Annual carbon sequestration and total carbon storage
• % public trees vs. total trees
• % private vs. public tree ownership
• % impervious surface cover (this metric is negatively correlated with urban tree cover).
Percent canopy cover is a commonly used metric that measures the percentage of ground
covered by a vertical projection of the overall tree canopy (i.e., both publicly owned and
privately owned trees). Currently in the United States, there is a trend towards increasing urban
canopy cover in multifamily residential and office/business zones, while cover is decreasing in
single-family residential (SFR) zones.
As of this writing, the City does not have a current estimate of percent canopy cover across San
Luis Obispo; however, a 2012 study using aircraft-obtained remote sensing (LIDAR) data
estimated San Luis Obispo’s canopy coverage at 13.2 percent (Nessen, 2012). Canopy cover was
Page 93 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 47 of 99
found to vary by land use category, being highest for office properties (19.6%) and residential
areas (19.2%) and lowest in business parks (2.5%).
If 13.2 percent is an accurate measurement of San Luis Obispo’s canopy cover, it does appear
slightly low when compared to the average of 15 to 19 percent across California’s urban areas
(McPherson et al., 2017; USDA Forest Service, n.d.). If the City decides to set a community forest
target using percent canopy cover, it should first consider obtaining an updated estimate based
on a current LIDAR dataset.
Urban forest professionals have noted that one potential downside to reliance on percent
canopy cover is that it is difficult for a government agency to significantly influence tree cover
on a large (e.g., citywide) scale, because most trees are located on private property. It may be
more important to quantify what the City’s existing trees are doing in terms of providing
benefits, and to translate that into dollar amounts that can be highlighted in outreach efforts.
6. Data Analysis
The purpose of gathering data on the urban forest is to supply the planning and budgeting
process with information that is as complete and current as reasonably possible. Repeated
measures of the same metrics over time will provide the data to allow managers to determine
whether or not the City’s targets are being achieved.
Evaluation of this data may illuminate forest health- or growth-related trends that require
action. For instance, use of certain species or certain types of planting locations may need to be
changed, pruning cycles may need adjustment, or program funding and staffing may undergo
modification. Because of the likelihood that adjustments will be needed over time, it will be
important for the City to retain flexibility by taking an adaptive management-based approach.
A number of private-sector firms specialize in forest management analysis software and/or offer
consulting services to cities and other agencies. Thus, the City may choose either to analyze its
urban forest data in-house or to hire a vendor to do so.
B. Strengthen Maintenance Practices and Clear the Backlog
As discussed in the DRG OA report, as of 2021 the City’s urban tree maintenance was estimated
to be one full cycle (8-10 years) behind due to staff injuries, retirements, and the effects of the
Covid-19 pandemic. Deferred maintenance can lead to tree decline and death from a variety of
maladies; thus it is important to properly care for existing trees to maximize their health,
longevity, and therefore the many benefits they provide. In 2021, in addition to performing the
City’s public tree inventory update, West Coast Arborists (WCA) was contracted to begin an
expedited pruning program to address the City’s multi-year tree maintenance backlog.
Page 94 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 48 of 99
The WCA Inventory Overview summary report provided recommendations to the City around
routine trimming (pruning), removals and inspections, and planting, as follows:
• Routine Trimming: Systematic tree maintenance based on a grid system can help
protect urban forest health and reduce costs over the long term. WCA’s summary report
identified:
o 10,156 public trees in the city that should receive routine trimming
o 114 diseased or declining trees that may soon need to be removed
o 29 trees in need of greater pruning intervention to address structural defects,
and
o 1,703 young trees that are still staked and will continue to need a higher level of
care until they have established.
Zonal pruning is currently being carried out by contractors based on the City’s nine
designated pavement maintenance areas. WCA recommends that the City commit to a
roughly three-to-five-year pruning cycle, except in the case of palms and other trees
that require more frequent maintenance.
• Removals and Inspections: WCA recommended the removal of 127 City-owned trees
and 327 other trees (owned by another agency or an HOA) due to their being dead,
diseased, or declining among other reasons. One additional tree in poor condition was
referred to City staff for inspection.
• Planting: WCA documented several hundred locations that once held trees but are now
either vacant (379) or contain only a stump (134). The former can be considered “low-
hanging fruit” that should be given high priority for planting and may also facilitate the
acquisition of grant funding by the City. The latter will require more preparation (stump
grinding) but should still be targeted for priority planting.
The City may also consider having a staff arborist conduct ad hoc “windshield surveys” of public
trees annually in order to detect existing or incipient problems in a timely manner.
C. Increase New Plantings and Implement the 10 Tall Initiative
There is wide agreement among urban forest experts and stakeholders (including the general
public) that increased tree planting is needed to counteract ongoing losses and to ensure the
presence of a future urban forest that maximizes social, economic, and ecosystem benefits to
city residents and visitors. Impacts resulting from excessive tree loss may be more pronounced
in cities that have little natural tree cover to begin with, like San Luis Obispo.
Page 95 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 49 of 99
In the past few years, the City has collaborated with local community groups including the
Rotary de Tolosa Club and ECOSLO to plant several hundred new trees across San Luis Obispo.
Building on these efforts, the City’s 2020 Climate Action Plan for Community Recovery (2020
CAP) called for rejuvenation and expansion of the City’s urban forest through the planting of
10,000 new trees by 2035. Subsequently, the City Council incorporated this proposal into the
City’s 2021-2023 Major City Goal for Climate Action, Open Space & Sustainable Transportation.
Streetscapes, City parks and facilities, creek corridors, open space areas, and private property
are all appropriate locations in which to consider the planting of additional public trees. The City
may also want to consider modifying its engineering standards to increase the number of trees
required in new development, including along sidewalks (currently, one tree per 35 feet) and in
parking lots. Alternatively, the City could require a specified number of trees per new dwelling
unit (residential), sq. ft. (commercial), or floor (multistory, all zones).
In parking lot areas, the City could consider requiring that groups of trees be installed in larger
islands to provide more cooling benefit to reduce public health concerns related to the urban
heat island (UHI) effect. Schoolyards are another type of land cover with large expanses of
blacktop; thus, students would also benefit from the shade and cooling provided by increased
tree canopy.
In 2019, local stakeholders created the 10 Tall tree planting initiative to raise awareness of the
benefits of urban trees and expand the city’s urban forest. 10 Tall is a City campaign nested in
the 2020 CAP, Pillar Six: Natural Solutions. 10 Tall continued to be a priority area of focus in the
City’s 2022 CAP update (CAP Volume 3, the 2023-2027 Work Program). City staff anticipate that
a large proportion (perhaps 40 percent) of the 10,000 trees proposed for planting will be native
species that will be planted in City open space areas and riparian corridors. Species diversity will
continue to be an important consideration, as best forestry practices suggest a forest
composition of no more than 10% of any single tree species, no more than 20% of species in any
tree genus, and no more than 30% of species in any tree family (Santamour, 2004).
Community engagement will also be an important part of the 10 Tall program. Dr. Jenn Yost at
Cal Poly San Luis Obispo has been working with computer science students at the university to
create a website where any community member – individual, household, or organization – will
be able to easily register trees they have planted within the City limits. The database linked to
the website will be accessible to the City and its tree care partners, and will be updated
quarterly to facilitate monitoring of progress toward the 10,000 tree goal as well as the
recording of urban forest metrics (e.g., diversity of species planted or survival at various time
points).
Survival of newly planted urban trees is typically much lower than 100 percent; one study found
that a “middle of the road” scenario is 50 percent survival at 13 to 18 years (Hilbert et al., 2019).
Page 96 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 50 of 99
It is not presently known how close the planting of 10,000 new trees would bring the City to a
target of 25 percent canopy cover (approximately double the 2012 estimate by Nessen), or
when exactly that might occur if the City chose to pursue that target.
D. Reexamine Tree Removal and Mitigation Policies
Tree removal and replacement requirements are provided in Section 12.24.090 of the Municipal
Code. In 2019, the City’s Public Works Director oversaw revisions to this section of code in order
to make the standards clearer and more objective; however, various concerns voiced by the
public around both construction and non-construction related tree removals remain.
Most removals of otherwise healthy trees within the City, whether public or private, require a
permit and replacement planting plan approved by the City Arborist. If the removed trees are
replaced on-site the replacement ratio is 1:1, while off-site replacement is at a 2:1 ratio (two
new trees for each removal). The City Arborist has the discretion to increase the required
mitigation on a case-by-case basis if deemed warranted. Depending on the nature of the
removal request, residents may appeal the denial of a permit to the City Tree Committee,
Community Development Director, and ultimately the City Council.
Concerns raised by residents often involve non-permitted tree removals on neighboring
properties, lack of City follow-up to ensure that replacement trees actually get planted, and lack
of an alternative to replanting – such as an in-lieu fee paid into an urban forest or open space
acquisition fund – in cases where replanting is excessively burdensome or infeasible. Residents
have also expressed concerns over whether the code-specified replacement ratios are adequate
when large, healthy trees are approved for removal, as in the case of new development.
E. Focus on Sustainability
As awareness of global climate change has entered the general consciousness in recent years
and calls for action have become more urgent, the importance of urban forestry has begun to
receive more attention from the public. Tree planting has increasingly come to the fore as a
“low-hanging fruit” climate change solution (Mandel, 2021). In many locales, planting sites are
numerous and trees and volunteer labor are readily available. The number of tree planting
initiatives sponsored by government agencies, corporations, and other entities has dramatically
increased since the beginning of the 21st century.
However, the issue is more complicated than it may seem. Planting trees is just one small part of
sustainable urban forest management; without long-term care, new tree survival rates are
significantly lower than with regular maintenance. Furthermore, opportunities for missteps
abound in urban forestry – for instance, planting in the wrong location or planting species that
may not be resilient to the local effects of climate change. Thus, comprehensive planning is
Page 97 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 51 of 99
needed in order to avoid outcomes that diminish or negate the desired social, economic, and
environmental benefits that motivated planting in the first place.
1. Right Tree, Right Place
The “right tree, right place” concept ties together various aspects of sustainability that are
discussed on the next several pages.
A thriving, productive urban forest contains a mix of species and individual trees that are
appropriate for the physical location and environmental conditions in which they were planted.
Urban trees, particularly street trees, are subjected to more challenging conditions and have
shorter lifespans than trees in more natural environments when compared to open space or
wildland trees (Smith et al., 2019). Average street tree lifespan has been estimated at 19 to 28
years (with a survival rate of new plantings ranging from 94.9 to 96.5%), while overall average
urban tree lifespan (including parks and residential trees) is estimated as 26 to 40 years (Roman
and Scatena, 2011).
Thus, determination of what constitutes “right tree, right place” should be made for each
individual combination of planting site and tree to maximize health, productivity, and longevity.
Failure to do this may result in reduced tree vigor, premature illness, and death, or premature
tree removal due to unwanted impacts on utilities or other infrastructure, not to mention
reduced or unrealized urban forest benefits.
Broadly speaking, sidewalk parkways and road medians are generally more suitable for smaller
trees that generate less organic debris, while larger species that drop more biomass but store
more carbon and create better wildlife habitat are appropriate for use in parks, riparian
corridors, or open space areas. While urban foresters commonly favor large-growing tree
species for maximization of ecosystem services (USDA Forest Service, 2004), city residents tend
to prefer smaller, fruiting or flowering trees for their aesthetic benefits (Eisenman et al., 2021).
One example of a species that is not particularly well-suited for San Luis Obispo is the coast
redwood (Sequoia sempervirens). The city’s climate is very dissimilar to the fog-shrouded, damp
coastal environment where redwood grows naturally. While some local redwoods are
reasonably healthy, many others are in poor condition, unable to thrive in our present climate
and presumably even less so in the future considering the predicted effects of climate change.
As another example, the huge, beautiful Indian laurel figs (Ficus microcarpa) in downtown San
Luis Obispo, while widely admired, have outgrown their environment. Cramped city sidewalks
are no longer an optimal location for these trees at their present size. On the other hand, palms,
although they do not offer much in the way of cooling or carbon sequestration, provide some
Page 98 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 52 of 99
degree of wildlife habitat and are appropriate for planting in areas of limited space.
Furthermore, palms are culturally important in southern California.
Lastly, interest in urban agriculture and edible landscaping have increased in recent years, with
many cities creating city gardens and even a few orchards. Many citizens have wondered why
food-producing trees are not typically included in urban street or park plantings. This, again, is
mostly a case of “wrong tree, wrong place.” Fruit and nut trees are avoided in most public urban
forest settings for a number of reasons: they’re highly susceptible to pests and disease,
relatively small and short-lived, create potential liability issues, and are generally very high-
maintenance. Thus, the most appropriate potential settings for public food-producing trees are
either a municipal orchard on public land, or possibly plantings on school grounds as part of an
urban agriculture educational program.
Tree Lists
A municipal tree list is a compilation of city-approved tree varieties that is maintained by some,
though not all, cities. Examples of factors that may go into a municipal tree list include whether
a given species has a propensity for disrupting sidewalks and utilities, is a nuisance due to
dropping debris or releasing excessive pollen, is compatible with local climate and soils, and is
aesthetically suitable for its intended location.
In some cases, municipal tree lists have been perceived as limiting and drawn complaints from
the public. The San Luis Obispo City Arborist has the authority to approve planting of additional,
non-listed species on a case-by-case basis. In addition, the City Tree Committee may work with
City staff and partners to update the tree list as often as once a year to remove less-than-
desirable trees (for example, those that require excessive amounts of water) and replace them
with climate-ready varieties. On the other hand, the City may also consider other options
including eliminating the tree list altogether (some cities do not have one), creating multiple lists
(one for streets, one for parks, one for open space, etc.), or adopting a list of non-approved
trees – i.e., banning the most problematic species while not regulating other species.
Given the already alarming effects of climate change, with worse projected to come, Californian
cities with urban tree lists are now in the position of having to update their lists for the future.
As of early 2023, San Luis Obispo has been working with Dr. Matt Ritter at Cal Poly San Luis
Obispo’s Urban Forest Ecosystem Institute (UFEI) to finalize a revised City Street Tree List
focused on climate-resilient trees, which will be presented to the City Council for approval later
in 2023.
Ideally, decisions about the City Street Trees List will continue to be informed by the latest
research on climate-resilient trees, like that occurring at UFEI. However, even when or if such
species are found, the desired trees may not be commercially available. A small number of
wholesale growers in California have expressed interest in experimenting with new species of
Page 99 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 53 of 99
climate-ready trees to meet projected demand, but thus far these have been the exception, not
the rule.
Thus, identification of what constitutes “right tree, right place” in 21st century San Luis Obispo is
work in progress. Regardless, it can no longer be considered appropriate to simply choose urban
trees based on cost alone or on whatever is available in the greatest quantities, without
accounting for resilience to changing environmental factors.
2. Climate Readiness
Climate readiness refers to the resilience of an urban forest to environmental stressors resulting
from the effects of global climate change (McPherson et al., 2018). Climate change has been
predicted to inflict increasing heat, drought, wildfire, and extreme weather events on California
in the coming years and decades, while also increasing exposure to attack by current or
emerging insect pests and pathogens. Furthermore, these effects may be exacerbated in cities
due to the urban heat island effect, air and water pollution, poor soils, and accidental or
intentional damage (vandalism).
Lack of irrigation water may also become cause for concern. As with many other cities, San Luis
Obispo contains numerous examples of ornamental trees that originated in wetter climates and
which require substantial irrigation in order to thrive. These varieties are not considered
adaptable to the projected, increasingly harsh environmental conditions accompanying climate
change and therefore will likely experience increasing decline and death in the coming years,
whether directly from climatic conditions or from property owners reducing or discontinuing
irrigation (on the other hand, water conservation measures and recycled water are still largely
untapped resources whose use may be expanded). Drought-weakened trees will also
increasingly comprise a public safety hazard, with associated financial costs. For all these
reasons, research to identify and test the resilience of potential new urban tree species is
urgently needed to protect the long-term stability of urban forests (McPherson and Berry,
2015).
In California, researchers with the University of California, UC Davis, and the USDA Forest
Service are conducting a study on this subject. The Climate Ready Trees project aims to identify
the suitability of underutilized but promising tree species for urban planting in the context of
climate change pressures (McPherson et al., 2018). Dozens of trees have been planted for
evaluation in the Sacramento area and throughout southern California. Although growth and
survival monitoring is ongoing, initial observations from southern California indicate that some
species native to hot, dry landscapes are performing better in inland locations than in coastal
locales, while others are tolerant of coastal conditions but require frequent pruning for optimal
growth and health (McPherson et al., 2020). Overwatering is a stressor for some of these
species and can result in crown growth that outpaces root growth, with poor outcomes.
Page 100 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 54 of 99
3. Urban Forest Diversity
Diversity is a core ecological concept that refers to the variety and relative abundance of a
species (Magurran, 1988). High species diversity, age diversity, and geographic distribution are
believed to lead to greater population resilience because although decimating factors (e.g.,
pests and disease, natural disasters, exploitation by humans) may act upon specific portions of a
diverse population, a single event is unlikely to eliminate the entire population of that species.
In contrast, monocultures or other areas of limited diversity are theoretically at higher risk of
being eliminated by a single decimating event. High tree species diversity can also enhance
benefits including aesthetics and wildlife habitat.
Urban forests in the US typically have far higher species diversity than adjacent native forests or
woodlands (Robertson and Mason, 2016). In California, overall urban tree species diversity is
considered adequate, but 39 of 49 inventoried communities were identified as being over-
reliant on a single species of street tree (typically London plane, sweetgum [liquidambar],
Chinese pistache, velvet ash, or Callery pear) (McPherson et al., 2016). This is in part because
commercial tree growers naturally meet demand by focusing on varieties that are easiest to
grow and sell most readily to high-volume buyers. When one of these trees dies or is removed,
it may be wise to consider replacing it with a different, more appropriate species. One suggested
best practice for urban forestry is to aim for a forest composition of no more than 10% of any
single tree species, no more than 20% of species in any tree genus, and no more than 30% of
species in any tree family (Santamour, 2004).
San Luis Obispo contains some individual trees of uncommon species that were planted long ago
but for which replacements from the same species are no longer available, contributing further
to concerns about declining species diversity in the city over time. The 2022 West Coast
Arborists tree inventory update commissioned by Public Works should be helpful in assessing
urban tree diversity in the city, even though it only includes street, park, and City facility trees in
the public right-of-way.
4. Pests and Disease
With each passing decade, the number of non-native, invasive pests and diseases in California
increases through commercial activity or other means of transportation from distant areas.
When these organisms establish self-sustaining populations, the result can be tens or hundreds
of millions of dollars in damage and mortality, whether to crops, wildlands, or urban plants and
trees. In urban forestry, the costs associated with managing pests, disease, and dead trees are
unavoidable; action must be taken due to public safety hazards such as falling trees and
increased wildfire risk.
Page 101 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 55 of 99
San Luis Obispo County has been living with one such invasion since at least the early 1990s. The
disease pitch canker, caused by the fungus Fusarium circinatum, was inadvertently introduced to
California (Santa Cruz County) in 1986. This pathogen has caused enormous die-off of pines in
California, including the widely planted Monterey pine (Pinus radiata). In San Luis Obispo
County, pitch canker was first detected in Cambria in 1994. Cambria’s native stand of Monterey
pine – one of three in California – is generally acknowledged to be in poor condition due in part
to the effects of this disease. The associated concerns include increased wildfire and falling tree
hazards, as well as reduced property values.
It is possible that this unfortunate situation could be repeated in other tree species in San Luis
Obispo County before long. Sudden oak death (SOD), caused by the fungus-like microbe
Phytophthora ramorum, is estimated to have killed over one million trees, mostly oaks and
tanoaks, in coastal California since its discovery in the mid-1990s (UC Riverside CISR, 2022). SOD
also infects dozens of other native plant and tree species, and it is currently documented in
southern Monterey County – just a few miles from the San Luis Obispo County line. Research
indicates that the strongest predictor of SOD is the presence of California bay laurel
(Umbellularia californica; California Oak Mortality Task Force, 2021) – a native tree that grows in
abundance in San Luis Obispo’s riparian and open space areas.
The invasive shot hole borers (ISHB), two closely related species of tiny wood-boring beetles
from Vietnam and Taiwan, were first detected in large numbers in southern California between
2012 and 2014. These beetles attack 58 tree species, killing the trees in two ways: by girdling
(tunneling through living tissues), and through the introduction of fungi of the genus Fusarium
which eventually clog the tree’s vascular tissues, preventing the movement of water and
nutrients. In 2017, ISHB was predicted to have the potential to kill 27 million trees in southern
California (Eskalen and Lynch, 2017). As of this writing, exactly one ISHB specimen has been
found in San Luis Obispo County, in 2016. The County Agricultural Commissioner’s Office is
conducting limited monitoring to watch for this pest.
In each of these cases and others of concern not discussed here (e.g., goldspotted oak borer –
Agrilus auroguttatus), widespread establishment of the pathogenic organism would be a serious
threat to anywhere from one to dozens of native and urban trees species in San Luis Obispo
County. For this reason, the CFP must address the City’s response to invasive species affecting
the City’s urban forest. In addition, some types of urban trees may themselves be considered
invasive species, e.g., tree of heaven (Ailanthus altissima), black locust (Robinia pseudoacacia),
Peruvian pepper (Schinus molle), Canary Island date palm (Phoenix canariensis), and certain
Acacia and Eucalyptus species.
Prevention and monitoring are essential; the City must work with partners including San Luis
Obispo County, CalFire, Cal Poly, PG&E and others to keep up with the latest information and
best practices. As regards prevention, it was noted previously that one factor strengthening the
Page 102 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 56 of 99
urban forest is species diversity. In reforesting the City’s open space and creek areas as part of
the 10 Tall campaign, it is natural to focus on planting San Luis Obispo’s native riparian tree
species (sycamores, cottonwoods, willows, maples). However, consideration must be given to
the susceptibility of these species to each invasive pest of concern, to the extent possible.
For instance, the experience with ISHB in southern California has shown that the riparian tree
species listed above seem to be these insects’ most highly preferred hosts. Thus, in light of the
potential threat to San Luis Obispo County, it may be prudent to consider reducing the
proportions of those species planted in the City’s open spaces and creeks, replacing them with
less-affected ISHB host species such as coast live oak (Quercus agrifolia), or with species like
California black walnut (Juglans californica) that have not been identified as hosts of ISHB.
Upon detection of a novel pest, a rapid, IPM (integrated pest management)-based response will
be required. The basic steps include quarantine, cultural practices including tree removal where
indicated, and use of insecticides and biocontrols (as available and deemed necessary). Thus,
the City should have funds available to respond to fast-breaking situations using an “early
detection, rapid response” mantra.
5. Lifecycle Perspective
Upon removal, urban trees have traditionally been considered to have little value and chipped,
burned, cut into firewood, or buried in a landfill (Nowak et al., 2019). However, these practices
either quickly or eventually allow the carbon stored in the wood to escape to the atmosphere.
Furthermore, a potentially useful job-producing and income-producing resource – to the tune of
46 million tons of wood per year, worth anywhere from $89 million to $786 million – is largely
wasted. Even a year’s worth of leaf litter from the US is estimated to contain $551 million in
nutrients that could be turned into mulch or fertilizer (Nowak et al., 2019).
Thus, one way in which the CFP can contribute to sustainability is by promoting adoption of a
lifecycle perspective toward urban trees – that is, acknowledging that each tree serves one or
more distinct purposes from planting through removal and subsequent use of the lumber and
other organic debris. This concept requires a philosophical shift from “planting trees” to
“growing trees” (Mandel, 2021); that is, a change of focus to long-term maintenance practices
that encourage a lifetime of arboreal health.
As such, the CFP includes a recommendation for the City to develop and implement an urban
wood lifecycle plan, which would include a replacement program based on planned rotation
(age at replacement) and “right tree, right place” principles. Probable replacement age for at
least some of the City’s newly planted street, park, and City facility trees that survive to maturity
would be between 20 and 30 years. This is an important concept because trees that have
outgrown their optimal growing space result in higher maintenance costs for City taxpayers than
Page 103 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 57 of 99
smaller trees, as seen with downtown San Luis Obispo’s 60-year old Indian laurel fig (Ficus
microcarpa) trees (see Section F, Address Issues Unique to Downtown).
Interest in alternative uses of urban waste lumber has been rising for a number of years now.
The benefits of this approach include reduced wood waste in landfills, increased urban jobs,
reduced need for harvesting rural forests, and potentially avoided carbon emissions and
enhanced municipal forest management revenue (Nowak et al., 2019). The lumber can be used
in a wide variety of ways, including as feedstock for engineered woods, landscape mulch, soil
conditioner, animal bedding, compost additive, sewage sludge bulking medium, and boiler fuel
(CalRecycle, 2022c).
However, waste lumber can also be used in the creation of boutique furniture or wood paneling
(“biophilic design”), public art, or infrastructure such as fencing or benches. These uses store the
carbon within wood indefinitely. Public installations using this material could be installed
throughout the city with educational signage around sustainability. San Luis Obispo company
Pacific Coast Lumber was featured in a 2016 news story using urban lumber to create just such
products, building handcrafted cabins, sheds, benches, tables, chairs, and flooring among other
products from dead and diseased Monterey pines that were removed from Cambria’s pine
forest (Buffalo, 2016). In order for this idea to work long-term in a city setting, urban forest
managers would need to consider lumber quality in addition to the various other desired
benefits from trees under their care when choosing trees to plant.
In a related project, in 2020 the local nonprofit ECOSLO received a CAL FIRE Urban and
Community Forestry grant for a program called “Full Circle: A Sustainable Approach to Urban
Lumber in San Luis Obispo” (CAL FIRE, 2020). This multifaceted project would divert 600 urban
logs from the waste stream over three years, plant 240 new trees, and create a new college and
vocational curriculum, donating wood to and working with local schools to teach students about
the sustainable processing and use of urban wood. ECOSLO contracted with local business
Deadwood Revival Design for program implementation. As of this writing, the Full Circle
program is in progress.
Urban lumber can also be used in cogeneration, the creation of bioenergy (electricity, heat, fuel)
from waste biomass. Although some carbon dioxide is generated and escapes to the
atmosphere in this process, the net effect is reduced GHG emissions and air pollution (including
methane) through the replacement of dirtier, fossil-fuel based equivalents. Finally, waste
biomass from tree removal can be used to create biochar, a charcoal-like material that when
added to soil can store carbon in the ground for thousands of years, while improving the soil’s
nutritional and moisture-holding capacity (Hawken, 2017, pp. 64-65).
The Hitachi Zosen-INOVA dry anaerobic digester near the San Luis Obispo airport reduces
greenhouse gas emissions by diverting green waste and food waste from the Cold Canyon
Page 104 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 58 of 99
landfill and recycling them into compost, liquid fertilizer, and electricity (Hitachi Zosen Inova AG,
2021). However, the facility cannot process large woody debris; SLO County does not currently
have any facility that can do so.
6. Soil Enhancement and Stormwater Management
Street trees typically exist in harsh urban environments with poor soil conditions. Urbanization
results in the conversion of natural land cover to impervious surfaces, changing natural drainage
characteristics and inhibiting infiltration of water, gases, and nutrients into the soil.
Furthermore, urban trees commonly suffer from other challenging growth conditions including
lack of growing space, soil compaction, high salinity, and/or unfavorable pH, and they can be
damaged by pollution and physical interference from infrastructure. These conditions can stunt
trees and plants, significantly limiting their health and lifespan (Lawrence et al., 2012).
Compost Procurement under SB 1383: California’s Short-Lived Climate Pollutant Reduction law
(SB 1383) establishes methane reduction targets through diversion of organic waste that would
otherwise go into the landfill (CalRecycle, 2022a). The law requires recycling of food waste and
addresses hunger through the recovery of edible food from the waste stream. Under SB 1383,
counties and cities are required to procure a certain tonnage of compost each year for their own
use or for donation to the community. The City of San Luis Obispo’s compost procurement
target for 2022 through 2026 is 3,685 tons per year (CalRecycle, 2022b). Because this amount of
compost exceeds current known uses for it, a potential exists for the surplus to be used in City
tree planting and care, as well as in application to City open space rangeland (carbon farming) if
various concerns, including plastic contamination, can be addressed.
Soil- and Infiltration-Enhancing Technologies: In recent years a variety of new soil-enhancement
technologies have been developed for the dual applications of stormwater infiltration/water
quality improvement and urban tree growth enhancement. These products are designed to
improve infiltration and remove suspended solids and other soluble pollutants while facilitating
the growth of larger trees than would otherwise be possible in confined urban settings, without
damaging sidewalks, streets, or utilities.
One of these solutions is engineered soils, which consist of specific, proprietary blends of gravel,
sand, silt, clay, and organic matter. By improving soil structure and chemistry, engineered soils
can enhance tree and landscaping root growth and therefore overall health. This can be
especially important in physically constrained planting sites such as small tree wells or planters.
However, this type of product must be used with carefully chosen tree species due to its
sometimes low nutrient content.
Engineered soils are sometimes considered one of the most practical and cost-effective soil
technologies for a city to use, although they are not inexpensive. For example, approximately 11
Page 105 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 59 of 99
yd3 of Cornell engineered soil (CU-Structural Soil®; Denig, 2015) is recommended for the
planting of a single street tree. At a typical price of $40 per yd3 (range = ~$35 to $75/yd3), this
comes out to $440 per tree.
Another tree growth-enhancing product is soil cells such as the Silva Cell (Deeproot Green
Infrastructure, 2022a). These “modular suspended pavement systems” consist of crate-like
structures, posts, panels, geotextile fabric, and mesh that are assembled in excavated trenches
where trees will be planted and backfilled with planting soil.
Soil cells work well although their cost – $14 to $18/ft3 installed, or approximately 10 times
more expensive than the Cornell soil referenced above – makes them likely to be cost-
prohibitive for most public planting situations. On the other hand, their proven ability to
enhance long-term tree growth and health means that these products might be suited for
limited use in challenging, streetside planting areas such as along Monterey, Higuera, and Marsh
Streets in San Luis Obispo. Private commercial or residential development can also benefit from
the use of soil cells; the City might consider requiring soil cell installation as a condition of new
development under some circumstances.
Additional products that the City might consider include water-absorbing polymers (hydrogels)
added to the soil, rubber sidewalks, suspended sidewalks, and pervious (permeable) concrete or
other hardscape surfaces.
7. Safety
In January 2023, the San Luis Obispo City Council adopted a revision of its General Plan Safety
Element. The new version – the Climate Adaptation and Safety Element (CASE) – serves as both
a Safety Element and an Environmental Justice Element, promoting public health and safety
relating to damage from both natural disasters (e.g., wildfire, drought, flooding) and exposure of
disadvantaged communities to toxic conditions (e.g., pollution).
The City of San Luis Obispo is also a participant in the 2019 Multi-Jurisdiction Local Hazard
Mitigation Plan (LHMP) spearheaded by San Luis Obispo County (County of San Luis Obispo,
2019). The LHMP relies on risk and vulnerability assessments to craft goals, objectives, and
actions that provide “practical, meaningful, attainable and cost-effective mitigation solutions to
reduce vulnerability to the identified hazards,” thereby reducing human and financial losses. The
LHMP evaluates 16 potential hazards facing the county and its communities, identifying tree
mortality resulting from drought stress and pathogen attack as a significant hazard. Other tree-
related hazards include adverse weather and wildfire.
Wildland Fire: Homes and other buildings throughout the city are located in close proximity to,
or interspersed with, hillslopes containing stands of native trees and brush. This zone of mixed
Page 106 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 60 of 99
land cover is known as the wildland-urban interface (WUI). The past two decades of increasingly
severe and uncontrollable fires in the western US have shown that the physical effects of
climate change on wildfire behavior (e.g., higher wind speeds, lower relative humidity and fuel
moisture, potential for large areas of drought- or pest/disease-killed vegetation) have now, in
many instances, intensified beyond the point at which fire suppression efforts are effective let
alone safe for fire crews. However, this reality does not obviate the need for the City to continue
to strengthen its defensible space regulations and conduct fuel reduction treatments in the
WUI; thus, urban forest planning must assess wildfire vulnerability.
Flooding: Much of the city’s urban development is located near the city’s creeks, within or in
proximity to 100-year and 500-year flood zones. Flooding can be caused by rocks, trees, and
other debris falling into waterways and blocking culverts and creek channels. This effect may be
exacerbated after a wildfire, particularly in steeper watershed areas, as the lack of vegetation
and eventual decay of fire-killed roots mean that the soil is more vulnerable to erosion. Other
effects of flooding can include inundation of structures, impact damage from flood flow and
debris, crop destruction, and release of hazardous materials including untreated sewage.
Flooding is appropriately considered in an urban forest management plan, as trees can both
help mitigate flooding, and contribute to it.
8. Water Conservation
Given the increasing unreliability of winter rains in central California, water conservation is
necessarily an important part of the conversation around San Luis Obispo’s urban forest. New
policies, practices, and technologies – as well as increased reliance on existing ones – are
needed going forward.
Substantial, and as yet unrealized, water savings are possible in California through more
stringent water conservation, recycling, and stormwater capture efforts (Gleick et al., 2014). The
City of San Luis Obispo currently uses tree watering bags on many of its trees, and uses recycled
water (indicated by purple signs and piping) for irrigation of other street and park trees (City of
San Luis Obispo, 2022b). While a detailed examination of water-saving methods is outside the
scope of the CFP, irrigation practices bear brief discussion here.
The City currently uses sprinkler, drip, and manual irrigation to water public landscaping,
including turf and trees. In many park and some street tree locations, as well as in new
development, the City is using or requiring use of recycled water. Minimization of turf and
conversion of sprinkler irrigation to drip should be a high priority for the City. Newly planted
trees planted in streetscapes, medians, parks, and other locations in the public right-of-way can
be located so as to take advantage of existing irrigation, but in some cases the City may choose
to install temporary or permanent drip irrigation to serve new plantings. If the City decides to
Page 107 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 61 of 99
try any of the technologies described above in the section titled Soil Enhancement and
Stormwater Management, drip irrigation could be incorporated into the design.
F. Address Issues Unique to Downtown
For decades now, downtown San Luis Obispo has attracted thousands of residents and visitors
year-round through special events held in Mission Plaza and City parks, the weekly Downtown
Farmer’s Market, and everyday shopping, dining, and entertainment opportunities. Downtown’s
lush tree canopy provides an ambience that enhances and serves as backdrop for these
activities. Accordingly, the City’s Downtown Concept Plan (DCP) and the Mission Plaza Concept
Plan (MPCP) (both 2017) recognize and support the importance of maintaining downtown’s
urban forest.
In fact, San Luis Obispo’s central business district would be unrecognizable to most locals
without its big, beautiful trees – notably including its iconic, roughly 60-year-old Indian laurel
figs (Ficus microcarpa). These enormous evergreen trees were planted widely across urban
California during a beautification craze in the 1960s, based on their reputation as hardy “miracle
trees” that could withstand heat, drought, air pollution, and any other number of hardships
(Gordon, 1996).
These trees dominate downtown San Luis Obispo and many other cities in California,
contributing tremendously to aesthetics and sense of walkability. Their large, shady canopies
confer a pleasing “sense of place” that encourages spending time outdoors, whether alone or in
social gatherings, and increases contentment. The presence of these trees raises property values
and drives increased retail business traffic.
However, the same trees drop leaves, twigs, and fruit on pedestrian walkways; attract birds and
insects that can cause distress by entering businesses; block views and street signs; invade
sewer lines; and, crucially, incur ongoing taxpayer expense through their need for expensive
maintenance. According to Cal Poly San Luis Obispo’s SelecTree website, Ficus microcarpa’s
branch strength is “medium weak,” they are a potential human health irritant due to the
allergens and latex-containing sap they produce, and they are not “powerline friendly”
(SelecTree/UFEI, 1995-2022).
By the mid-1990s, cities throughout California had either stopped planting Ficus microcarpa for
these reasons or were actively tearing them out and replacing them with palms, often to the
consternation of tree lovers (Gordon, 1996). Some southern California cities, reluctant to cut
down these popular features of their downtowns, have opted to play the waiting game by
performing root trimming, installing underground root barriers, and replacing sidewalks with
stone pavers around the trees. However, the overall feeling on the part of arboricultural
Page 108 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 62 of 99
professionals seems to be that this is a case of “wrong tree, wrong place” – that these trees
have simply gotten too big for their surroundings.
As the number of Ficus and other large, 1960s-era trees in downtown San Luis Obispo slowly
dwindles through attrition, it is likely that a replacement program based on planned rotation
and “right tree, right place” principles will be created, as discussed previously under “Lifecycle
Perspective.” The most likely plan is for a regular 20- to 30-year replacement cycle to be
established. Some trees of the same species, including Ficus microcarpa, may be replanted but
they will not be allowed again to attain such enormous size in cramped sidewalk spaces.
In future decades, the vision for downtown SLO is that it will have a more diverse, mixed-age
and mixed-species tree palette containing a preponderance of species that, while still beautiful
and inspiring, do not have the potential to grow as large as the current specimens and cause the
aforementioned problems.
G. Increase Outreach to Officials and the Public
The use of public outreach and engagement to build support for urban forestry is essential
because, although research has found that overall public support for tree planting is high, trees
also have downsides. They can be messy, damage sidewalks and underground utilities, comprise
a safety hazard by dropping limbs or falling, attract insects, in some cases trigger allergies with
their pollen, block views, and be expensive to water and maintain (Conway and Bang, 2014;
Ziska et al., 2019). In addition, some tree species emit high levels of volatile organic compounds
(VOCs) that may contribute to the formation of ground-level ozone when combined with
human-generated pollutants (Churkina et al., 2017).1
Furthermore, many urban forest benefits are intangible and therefore not obvious and/or
meaningful to the general public. Residential planting and removal of trees is based far more on
personal preferences such as aesthetics or maintenance concerns than on consideration of tree-
related ecosystem services. In general, tree-based information highlighting benefits that are
more inherently obvious to the general public (e.g., landscape beautification, cooling and
reduced energy bills, wildlife habitat) should have a greater impact on driving support for the
urban forest than more specialized information regarding ecosystem services (e.g., air pollution
removal or reduction of flooding and erosion). However, given that the dollar value of
environmental services provided to a city by urban trees can easily be in the millions of dollars
annually in costs avoided, the City still might consider broadly publicizing ecosystem services as
a reason for continued support and growth of the taxpayer-funded urban forest program.
1 It should be noted, however, that many of these undesirable effects can be minimized through planning and
regular maintenance.
Page 109 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 63 of 99
The City and its partners can enhance public interest and participation in urban forestry efforts
by continuing with existing outreach programs, creating new ones, and by planning for and
hosting special events. One “low-hanging fruit” example would be to maintain the City’s existing
Tree City USA designation with the Arbor Day Foundation. As of this writing, San Luis Obispo has
been a Tree City USA participant for 39 years. The participation requirements include
maintaining a tree board or department, having a community tree ordinance, spending at least
$2 per capita on urban forestry, and celebrating Arbor Day (Arbor Day Foundation, 2022). The
City has also been the recipient of two Gold Leaf Awards from the International Society of
Arboriculture (ISA).
H. Address Equity Issues
Green infrastructure and the associated health benefits are not equitably distributed in the
United States (Heynen et al., 2006; Landry and Chakraborty, 2009). Urban neighborhoods that
were targeted for systematic disinvestment in the past (i.e., redlining) commonly lack adequate
tree cover and other landscaping (Locke et al., 2021), depriving local residents of access to these
benefits and exposing the residents to higher temperatures (due to the urban heat island effect)
than are experienced in wealthier, tree-lined parts of the same city (Wilson, 2020).
This issue takes on even more importance in the context of increasingly severe climate change
effects (e.g., extreme heat, drought, wildfire, flooding). The cumulative result is poorer public
health and safety outcomes for the residents of tree- and landscaping-poor neighborhoods,
leading to the question, “How can a city ensure that environmental, social, and economic
benefits provided by the urban forest are equally distributed across all residents and
neighborhoods, both now and in the future?”
In San Luis Obispo, Diversity, Equity, and Inclusion (DEI) is both a Major City Goal in the 2021-
2023 Financial Plan and an important component of the 2020 Climate Action Plan for
Community Recovery. Davey Resource Group (DRG) addressed the topic of equity in their Urban
Forestry Organizational Assessment for the City Public Works Department (Davey Resource
Group, 2021). The Organizational Assessment states that while maintenance of trees in the
public right-of-way is equally distributed across the entire city and public parks are located
throughout the City, there are generally more opportunities for tree planting in newer
neighborhoods than in older ones.
However, there seems to be considerable uncertainty among San Luis Obispo residents around
this topic. Among DRG’s urban forest poll respondents (conducted in support of the
Organizational Assessment), 63% of those responding were unsure whether urban forest
benefits are equally accessible to all in the city, while 20% said they are not.
The DRG Organizational Assessment included the following recommendations regarding equity:
Page 110 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 64 of 99
• Conduct an assessment to explore the distribution of public tree canopy and associated
benefits by neighborhood, census tract, and/or other geographic metrics
• Coordinate with the City’s Diversity, Equity, and Inclusion Task Force to identify gaps in
equity as regards urban forest access and benefits
• Develop equity strategies around the urban forest.
The nonprofit organization American Forests maintains an online data tool called Tree Equity
Score that estimates the equitability of tree canopy distribution in a city based on tree canopy
cover, climate, and demographic and socioeconomic data (American Forests, 2022). The result is
a score (0 = lowest, 100 = highest) that is calculated at the neighborhood (Census block group)
level and aggregated to the municipal level.
San Luis Obispo has an overall Tree Equity Score of 74 out of 100 (Treeequityscore.org, 2022).
The two highest scoring block groups are located between Broad Street and Santa Rosa Street,
south of Foothill Boulevard and north of US 101 (score = 94; canopy cover = 27%), and an area
mostly south of Foothill Boulevard including Ramona Drive and La Entrada Avenue (score = 91;
canopy cover = 21%). The two lowest scoring block groups are an area around S. Higuera Street
that includes Elks Lane, Bridge Street, and Fontana Avenue (score = 55; canopy cover = 9%) and
the area immediately to the south of that but north of Tank Farm Road (score = 46; canopy
cover = 7%). The Cal Poly campus, although not within the city limits, also earned a low score, 49
(canopy cover = 12%).
Page 111 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 65 of 99
Appendix B: City of San Luis Obispo Designated Heritage Trees
San Luis Obispo's Heritage Tree Program serves to document the significant contributions of certain
trees, illustrate their historical value, and call attention to specimens of significant arboricultural
interest. Residents may nominate a tree for Heritage Tree status by contacting Urban Forest Services
within the Public Works Department.
Currently 15 properties within the city host one or more designated Heritage Trees, as shown on the
City’s Heritage Trees GIS webpage (Andrews, n.d.):
(https://storymaps.arcgis.com/stories/fbc1b607a9454c66b4fc643518bfc1df)
The City’s Heritage Trees area also listed in the summary table below. As of late 2022 one of the
Heritage Trees listed on the webpage, a cajeput tree (genus Melaleuca) at 1359 Palm St., had been
removed.
Heritage Tree(s) by Site Address
Dawn Redwood (Metasequoia glyptostroboides) 237 Del Mar Ct.
Torrey Pine (Pinus torreyana) 60 Casa St. (behind Sagrado Corazon Townhomes)
Cork Oak (Quercus suber) 382 Lincoln St.
California Bay Laurel (Umbellularia californica) Immediately south of Nipomo St. bridge over
Brizziolari Creek
Coast Redwood (Sequoia sempervirens) “Moon Tree” - south/west end of Mission Plaza
Japanese Maple (Acer palmatum) Jack House & Gardens, 536 Marsh St.
Incense Cedar (Calocedrus decurrens) The Monday Club, 1815 Monterey St.
Olives (Olea europaea) 1839 Conejo Ave.
Coast Redwood (Sequoia sempervirens) 1303 Higuera St.
Coast Redwoods (Sequoia sempervirens) Dallidet Adobe & Gardens, 1185 Pacific St.
Deodar Cedar (Cedrus deodara) 1190 Buchon St.
Western Redbud (Cercis occidentalis) 1060 Pismo St.
Shamel Ash (Fraxinus uhdei) Mitchell Park, 1400 Osos St.
California Sycamore (Platanus racemosa) Old Mission Cemetery, 101 Bridge St.
Incense Cedars (Calocedrus decurrens)
California Sycamores (Platanus racemosa)
Queen Palm (Syagrus romanzoffiana)
Blackwood Acacia (Acacia melanoxylon)
CalTrans District 5 Offices, 50 Higuera St.
The following pages contain photos taken at each Heritage Tree site in 2022. If visiting one or more of
these trees, please be respectful of residents’ privacy or posted hours of public access, as applicable. Do
not trespass on private property.
Page 112 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 66 of 99
A. Dawn Redwood, Del Mar Ct.
Page 113 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 67 of 99
Page 114 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 68 of 99
B. Torrey Pine, Casa St.
Page 115 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 69 of 99
Page 116 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 70 of 99
C. Cork Oak, Lincoln St.
Page 117 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 71 of 99
Page 118 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 72 of 99
D. California Bay Laurel, Brizziolari Creek
Page 119 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 73 of 99
Page 120 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 74 of 99
E. Coast Redwood, Mission Plaza (“Moon Tree”)
Page 121 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 75 of 99
Page 122 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 76 of 99
F. Japanese Maple, Jack House & Gardens
Page 123 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 77 of 99
Page 124 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 78 of 99
G. Incense Cedar, The Monday Club
Page 125 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 79 of 99
Page 126 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 80 of 99
H. Olives, Conejo Ave.
Page 127 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 81 of 99
Page 128 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 82 of 99
I. Coast Redwood, Higuera St.
Page 129 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 83 of 99
Page 130 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 84 of 99
J. Coast Redwoods, Dallidet Adobe & Gardens
Page 131 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 85 of 99
Page 132 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 86 of 99
K. Deodar Cedar, Buchon St.
Page 133 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 87 of 99
Page 134 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 88 of 99
L. Western Redbud, Pismo St.
Page 135 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 89 of 99
Page 136 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 90 of 99
M. Shamel Ash, Mitchell Park
Page 137 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 91 of 99
Page 138 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 92 of 99
N. California Sycamore, Old Mission Cemetery, Bridge St.
Page 139 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 93 of 99
Page 140 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 94 of 99
O. Incense Cedars, California Sycamores, Queen Palm – CalTrans District 5 Offices, Higuera St.
Page 141 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 95 of 99
Page 142 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 96 of 99
Page 143 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 97 of 99
Page 144 of 299
City of San Luis Obispo Community Forest Plan April 2023
Office of Sustainability and Natural Resources Page 98 of 99
Page 145 of 299
Page 146 of 299
San Luis Obispo Summary Report
Urban Forestry Organizational Assessment
2021
Page 147 of 299
Page 148 of 299
San Luis Obispo Summary Report
Urban Forestry Organizational Assessment
2021
Prepared for:
City of San Luis Obispo Public Works Department 990 Palm Street San Luis Obispo, CA 93401
Prepared by:
Davey Resource Group, Inc. 295 South Water Street, Suite 300 Kent, OH 44240 www.davey.com/drg
Page 149 of 299
Table of Contents
Introduction 1 Urban Forest Resource 3 Urban Forest Canopy 3 Community Tree Resource 4 Tree Inventory Management 5 Equity 8 Resource Threats 9
Climate Change 9
Drought 10
Pests and Pathogens 10
Resiliency Strategies 12
Operations and Programs 23
Services and Programs 24
Service Requests 24
Tree Pruning 25
Clearance and Visibility 28
Heritage Trees 28
Tree Planting 29
Commemorative Tree Program 31 Tree Selection 32 Irrigation 34 Tree Removal 37 Debris and Wood Utilization 38 Emergency Response 41 Community Engagement and Outreach 41 Development 43 Design 46 Safety 49 Urban Forest Partners 51 Internal Partners 51 Parks and Recreation Department 52 Community Development Department 53 Fire Department 54 Administration Department - Office of the City Manager 55
Administration Department - Office of Sustainability 56
Public Works Department - Maintenance Operations (Parks) 57
Advisory Bodies 58
San Luis Obispo Tree Committee 58
San Luis Obispo City Council 60
External Partners 61
Environmental Center of San Luis Obispo (ECOSLO) 61
Downtown SLO 62
Page 150 of 299
California Polytechnic State University (Cal Poly) 63 Organizational Structure and Staffing 65 Staffing 65 Equipment 71 Contract Management 72 Funding 74 Policy and Regulation 77
Federal and State Law 77
Endangered Species Act 77
Migratory Bird Treaty Act (MBTA) 77
Vegetation Management Standards 77
California Urban Forestry Act 77
Model Water Efficient Landscape Ordinance (MWELO) 78
California Global Warming Solutions Act 78
California Solar Shade Control Act 78
Climate Adaptation Actions for Urban Forests and Human Health 78
Guiding Documents for the Urban Forest 79
Municipal Code 79
San Luis Obispo General Plan 2035 80 Climate Action Plan For Community Recovery 82 2021-23 Financial Plan 83 Engineering Standards 83 Management and Performance Audit of the Public Works Department 84 Estimating Urban Canopy Cover in San Luis Obispo 84 San Luis Obispo Creek Stormwater Resource Plan 85 Parks and Recreation Blueprint for the Future 2021-2041 85 Resilient SLO 85 Additional Planning Documents 85 Benchmark Community Survey 87 Analysis of Sustainability Indicators 93 The Trees 93 The Players 95 The Management Approach 96
Conclusion 97
Appendix A: References 101
Appendix B: Industry Standards 104
Appendix C: Estimated Time on Services 107
Appendix D: Sustainability Indicators 108
Appendix E: Community Survey 118
Page 151 of 299
Tables
Table 1: Tree Canopy by Land Use in San Luis Obispo (Nessen, 2012) ...................................................... 4 Table 2: Sustainable Indicators ............................................................................................................................... 94 Table 3: Tasks and Estimated Time Spent by Urban Forest Services Staff ........................................... 107 Table 4: The Trees ...................................................................................................................................................... 108 Table 5: The Players ................................................................................................................................................... 111 Table 6: The Management Approach ................................................................................................................. 114
Figures
Figure 1: San Luis Obispo Urban Core Boundary in Red (Left) and Canopy Cover (Right) (Nessen, 2012) .................................................................................................................................................................................... 3
Figure 2: Tree Condition ............................................................................................................................................... 4
Figure 3: Relative Age Distribution ........................................................................................................................... 5
Figure 4: Tree Removal Flow Chart ........................................................................................................................ 38
Figure 5: Current Staffing Structure of Urban Forest Services .................................................................... 65
Figure 6: Staffing Recommendations ................................................................................................................... 68
Figure 7: San Luis Obispo Community Member Opinions on the Most Important Benefits of
Trees .................................................................................................................................................................................. 87
Figure 8: Community Member Opinions on the Most Important Environmental Benefit from
Trees .................................................................................................................................................................................. 88
Figure 9: Community Member Opinions on the Most Important Socioeconomic Benefit from
Trees .................................................................................................................................................................................. 88 Figure 10: Community Member Opinions on Where it is Most Important to Plant More Trees ... 89 Figure 11: Community Member Opinions on Encouraging Tree Planting on Private Property ..... 89 Figure 12: Community Member Awareness and Interactions with the Urban Forestry Program .. 90 Figure 13: Community Member Opinions on the Level of Care Provided for Community Trees .. 90 Figure 14: Community Member Opinions on Whether Urban Forest Services and Programs are Equally Accessible to all Residents ........................................................................................................................ 91 Figure 15: Community Member Opinions on Topics of Education and Outreach of Interest ........ 91
Page 152 of 299
Glossary of Acronyms
American National Standard Institute (ANSI)
Best Management Practices (BMP)
California Department of Forestry and Fire Protection (CAL FIRE)
California Polytechnic State University (Cal Poly)
Capital Improvement Project (CIP)
Diameter Breast Height (DBH)
Environmental Center of San Luis Obispo (ECOSLO)
Full Time Employee (FTE)
Integrated Pest Management (IPM)
International Society of Arboriculture (ISA)
Invasive Shot Hole Borer (ISHB)
Occupational Safety and Health Administration (OSHA)
Pacific Gas and Electric (PG&E)
Part Time Employee (PTE)
Rights-of-way (ROW)
San Luis Obispo (SLO)
Tree Risk Assessment Qualification (TRAQ)
Tree Care Industry Association (TCIA)
Urban Forest Strategic Plan (UFSP)
Page 153 of 299
1 Introduction
Introduction
The city of San Luis Obispo (SLO) places a great emphasis on creating a sustainable, resilient, livable, and vibrant community and both the community and the organization recognize and celebrate the role the urban forest plays in providing the quality of life for visitors and the community. Community members are actively involved and passionate about trees. This is evident from the many volunteers involved in tree planting, maintenance, and advocacy as well as the community’s consistent support of local revenue measures that provide funding for tree-related programs. The City’s achievements around the urban forest include 38 years as an Arbor
Day Foundation “Tree City USA” and two International Society of Arboriculture Gold Leaf
Awards. San Luis Obispo’s urban forest is made up of trees on public and private property. The
City’s Urban Forest Services, within the Public Works Department, is responsible for the care of
approximately 20,000 trees along streets, in parks, and at city facilities.
As outlined in the Climate Action Plan and the Financial Plan, the City intends to develop an
Urban Forest Strategic Plan (UFSP) in the near future. To begin that process, the City of San Luis
Obispo Public Works Department contracted with Davey Resource Group, Inc. (DRG) to review
the urban forest program, including the current structure and operations, background
documents, and existing policies. DRG also engaged key partners and community members and
conducted an online survey to gauge community awareness and support for the urban forest.
This document summarizes the findings from this review and provides recommendations for
consideration during the development of an Urban Forest Strategic Plan. The review process did not include an assessment of the entire urban forest (trees on private property, natural areas, and riparian buffers) or engagement with other governing bodies. Therefore, the findings provided in this report are not a comprehensive account of every consideration that should be addressed by a UFSP. DRG recommends that future planning phases include additional exploration on the role of the Tree Committee, objective design standards, compensatory planting requirements resulting from development, along with expanded engagement with key stakeholders and the community. Furthermore, Urban Forest Services is in a transition period and recently began to contract tree maintenance and inventory work. The next phase of development of a UFSP should assess any new information gathered on the resource from these activities.
The vision for San Luis Obispo is of a “sustainable community within a diverse
natural and agrarian setting, which is part of a larger ecosystem upon which its
existence depends. San Luis Obispo will maintain its healthy and attractive
natural environment valued by residents, its prosperity, and its sense of safety
and community, within a compact urban form…”
-Land Use Element of the General Plan
Page 154 of 299
Introduction 2
The findings in this report reflect input that was received from stakeholders and document known challenges and opportunities that should be considered by the City to make decisions around Public Works Department services and staffing levels. Each section of this report documents and benchmarks current conditions, challenges, and opportunities, and provides initial recommendations for the advancement of the urban forestry program and the development of a UFSP.
Page 155 of 299
3 Urban Forest Resource
Urban Forest Resource
An urban forest is a living and dynamic resource, changing over time and in constant response to its environment. The health and stability of the urban forest can be influenced by many factors, including pruning, irrigation, climate change, weather fluctuations, emerging pests and disease, as well as development and new tree planting. A complete understanding of the current extent of tree canopy within City boundaries, as well as the structure, condition, and maintenance needs of trees managed by the urban forestry program is essential to making the best possible management decisions.
Urban Forest Canopy
When looking at a subset of the City boundary that contains urbanized areas within San Luis
Obispo, there are 1,050 acres of tree canopy for an overall canopy cover of 13.2% (Figure 1;
Table 1). Canopy cover varies by land use category and is highest for office properties (19.6%)
and residential areas (19.2%) and lowest in business parks (2.5%). Tree canopy in residential
areas ranges from 15.4% in medium density to 20.6% in low density, with medium high and high
density falling in between (Nessen, 2012).
Figure 1: San Luis Obispo Urban Core Boundary in Red (Left) and Canopy Cover (Right) (Nessen, 2012)
Page 156 of 299
Urban Forest Resource 4
Table 1: Tree Canopy by Land Use in San Luis Obispo (Nissen, 2012)
Land Use Category Acres Canopy
Acres Canopy %
Residential 3,313.1 635.7 19.2
Public Facilities 981.4 91.8 9.4
Undeveloped 1,171.5 84.8 7.2
Manufacturing 1,013.0 76.9 7.6
Commercial 737.1 69.3 9.4
Office 232.4 45.6 19.6
Park 220.2 38.2 17.3
Business Park 311.7 7.9 2.5
Total 7,978.2 1,050.0 13.2
Community Tree Resource
The tree inventory includes 17,983 trees along streets, in medians, parks, and at city facilities. Although the inventory is outdated (last updated in 2008), the data is estimated to be between 90-95% accurate. The Climate Action Plan (2020) estimates there are currently 20,000 trees and additional planting opportunities in 15-25% of sites that are vacant.
Tree condition is an indication of how well trees are managed and how well they are performing in the region and in each site-specific environment (e.g., street, median, parking lot, etc.). Condition ratings can help managers anticipate maintenance and resource needs, as well as give a glimpse on the benefits the trees provide. The amount and distribution of leaf surface area is the driving force behind a tree’s ability to produce benefits for the community (Clark et al. 1997). Trees rated in the good or better category typically have full, healthy canopies and therefore
maximize benefits to the community. Thirty
seven percent of San Luis Obispo’s
community tree inventory is in good or
better condition (Figure 2). Typically trees in
fair condition have minor structural
problems, but reasonable vitality and therefore
also provide considerable benefits to the
community.
Excellent
0.4%
Very Good
0.9%Good
35.2%
Fair
54.8%
Poor
7.8%
Critical
0.1%Dead
0.8%
Figure 2: Tree Condition
Page 157 of 299
5 Urban Forest Resource
The relative age distribution of a species and for the overall resource can be approximated with consideration of the diameter (DBH 1) of individual trees. The age distribution of a tree population influences present and future costs as well as the flow of benefits. An ideally aged population allows managers to allocate annual maintenance costs uniformly over many years and assures continuity in overall tree canopy coverage and associated benefits. A desirable distribution has a high proportion of young trees to offset establishment and age-related mortality as the percentage of older trees declines over time (Richards, 1982/83). San Luis
Obispo’s inventoried trees show a nearly ideal age distribution (Figure 3).
Figure 3: Relative Age Distribution
Maintaining diversity in a community tree resource is important. Dominance of any single species or genus can have detrimental consequences in the event of storms, drought, disease, pests, or other stressors that can severely affect a community tree resource and the flow of
benefits and costs over time. Having a diverse tree resource provides resiliency to the urban
forest. Recognizing that all tree species have a potential vulnerability to pests and disease, urban
forest managers have long followed a rule of thumb that no single species should represent
greater than 10% of the total population and no single genus more than 20% (Santamour,
1990). There are 298 unique species in San Luis Obispo’s tree inventory. The most abundant
species, coast live oak (Quercus agrifolia), represents 10% of the overall resource. All other
species represent less than 5% of the overall resource and fall within these recommendations
but striving for greater diversity could provide even more benefits for resiliency.
Tree Inventory Management
In the past, the City used a tree specific inventory management software (ArborPro) to inventory community trees in rights-of-ways, streets, parks, city facilities, and heritage trees on private property. In line with a recommendation from the 2011 audit of the Public Works Department, the City integrated the tree inventory into Cityworks, an inventory management software used to track multiple assets within the Public Works Department (Management and Performance
1 DBH: Diameter at Breast Height. DBH represents the diameter of the tree when measured at 1.4 meters (4.5 feet) above ground (U.S.A. standard).
0%
10%
20%
30%
40%
0 - 3 3 - 6 6 - 12 12 - 18 18 - 24 24 - 30 30 - 36 36 - 42 42+% of PopulationDBH Class (inches)
ideal age distribution
total population
Page 158 of 299
Urban Forest Resource 6
Audit of the Public Works Department, 2011). Since the transition, that began in 2013 and ended in 2014, tree data has not been regularly updated in Cityworks, although staff does use Cityworks to track tree removal inspections as they occur. Currently, the Public Works Department is developing a request for proposals for a complete update of the tree inventory maintained by Urban Forest Services.
Currently, partnering departments and organizations do not have access to the tree inventory. For example, ECOSLO manages the inventory of trees the organization has planted in an online format and cannot integrate with the City’s existing inventory. During maintenance, inventory updates are conducted by contractors and occur in a separate program so data has to be uploaded into Cityworks quarterly.
A complete, up-to-date tree inventory housed in a comprehensive management system will strengthen the program. An inventory management system is a powerful tool that can be used to track trees that require pruning or removal for risk mitigation, record current characteristics of each tree (e.g., species, condition, size), map (GIS based) assets, develop maintenance cycles and work plans, create real-time workflows, analyze work history, and share data amongst divisions in the Public Works Department as well as other urban forest partners (Bond and Buchanan, 2006).
Challenges and Opportunities: Urban Forest Resource
• Tree inventory is out of date and not regularly updated as work occurs.
• The Public Works Department is planning to obtain a complete inventory of the trees they manage.
• The tree inventory has an approximate 10% error rate, with some errors in species identification.
• Urban forest partners provide the majority of new tree planting in rights-of-ways yet do not have access to update the existing inventory program.
• Tree canopy data is more than 10 years old and is not comprehensive.
• The stocking level for trees maintained by Urban Forest Services is unknown and vacant sites are not currently documented or tracked.
• Staff struggles to document and maintain the tree inventory data, especially for assets that require frequent maintenance.
Page 159 of 299
7 Urban Forest Resource
Recommendations for UFSP Planning: Urban Forest Resource
• Complete a comprehensive update of the tree inventory that includes data on all existing trees, vacant sites, stumps, and potential sites (per Climate Action Plan and Strategic Budget Direction Report).
Use this information to better understand the stocking level and potential for future planting.
• Update inventory database (as needed) when inspections or maintenance occur (per Climate Action Plan).
Confirm species
Update condition and maintenance needs (if applicable)
Update DBH
• Analyze and correct misidentified species in the tree inventory.
Explore opportunities for assistance from Cal Poly students.
• Allow urban forestry partners access to update the tree inventory.
Use administrative settings to control access and editable data
• Conduct a full land-cover assessment, including impervious surfaces (per Climate Action Plan).
Analyze historic change.
Explore canopy distribution and equity, especially for publicly managed areas
Explore canopy and planting potential.
• Maintain historic records of tree maintenance, update data as trees are pruned or removed and add new trees to the inventory as they are planted.
• Determine and account for the time it takes to keep the inventory up-to-date as work occurs for budgeting purposes.
• Use a common database tracking system amongst Urban Forest Services, contractors, ECOSLO, Office of Sustainability, Parks and Recreation, and any other partners so there are not redundancies or lag times in accessing data.
Page 160 of 299
Urban Forest Resource 8
Equity
Equity is an initiative for the City’s Climate Action Plan and Diversity, Equity and Inclusion is a Major City Goal in the
2021-23 Financial Plan. The City aims to consider the
distribution of the urban forest to increase the benefits from
trees, especially for residents most vulnerable to extreme
heat and flooding.
The City has the greatest ability to directly impact tree planting on City property followed by trees within the City
limits (excluding properties owned by state and county
agencies). In all maintenance zones, trees in rights-of-way
currently receive the same level of service. Parks are
distributed throughout the community so that all residents
have access to trees and tree canopy. In general, newer housing developments have more tree planting opportunities than what is available for houses in older neighborhoods. If a planting site is vacant, residents have an opportunity to request a tree.
Twenty percent of respondents to the online survey do not feel that urban forest services and programs are equally accessible to all. The Urban Forest Strategic Plan process should consider a comprehensive land-cover assessment, including analysis of rights-of-way, to explore distribution and quality of tree canopy across the community. Additional community engagement should explore concerns about equitable access to urban forest resources and services.
20% of community
survey respondents
did not think that
Urban Forest Services
and programs are
equally accessible to
all.
Challenges and Opportunities: Equity
• The current extent of tree canopy across the community is not known.
• Equity is a City initiative, but currently there is not coordination between Urban Forest Services and the Diversity, Equity, and Inclusion Task Force.
• The online survey indicated that 63% of community members are not sure if Urban Forest Services and programs were equally accessible to all and 20% feel they are not.
Page 161 of 299
9 Urban Forest Resource
Resource Threats
Like all urban forests, San Luis Obispo's trees are vulnerable to numerous stressors and threats. These threats may be specific to a particular host species, which means that the threat is more isolated. Other threats, like climate change, can affect a broader range of tree species and could result in significant loss in benefits and canopy cover.
Climate Change
Urban Forest Services recognizes that shifts in weather patterns are likely to alter species habitat ranges and render some species less adapted to the region. Research on climate change in complex urban ecosystems is challenging and still evolving. Although there is no clear consensus on the future outcomes, it is thought that extraordinary weather events are likely to increase in years to come. As temperatures rise and precipitation patterns fluctuate from historical norms, existing trees must adapt or succumb to the changes in climate.
Impacts on the urban forest program may include:
• Health and structural impacts on tree species that are not adapted to new and changing conditions.
• Increase in pests and disease as a result of changes in temperature, precipitation, and tree stress.
Recommendations for UFSP Planning: Equity
• Conduct a tree canopy and land cover assessment and explore the distribution of tree canopy (particularly in ROW) by neighborhood, census tracts, and other geographic metrics to better understand distribution and opportunities for additional canopy.
Analyze canopy distribution, cover, and urban forest benefits for equitable distribution, including for vulnerable populations.
○ Analyze canopy as it relates to flood zones and land surface temperatures.
○ Create linkages in areas with high tree canopy fragmentation.
• Explore the relationship between tree canopy and socioeconomic variables.
• Coordinate with the Diversity, Equity, and Inclusion Task Force to identify gaps in the equity of the urban forest.
• Explore how urban forest services and programs can be more equitable in the Urban Forest Strategic Plan development process.
• Develop equity strategies around the urban forest.
• Use trees to increase neighborhood wellness, aesthetics, and other quality of life improvements (per 2021-23 Financial Plan).
• Use trees to increase carbon sequestration and mitigate the effects of climate change (per 2021-23 Financial Plan).
Page 162 of 299
Urban Forest Resource 10
• Additional costs for mitigation (e.g., irrigation infrastructure) and tree removal for marginal species.
• Canopy loss, especially where key species (e.g., predominant species) become marginalized.
Tree species can adapt to climate change by shifting their range (e.g., expanding northward and to a higher elevation) or contracting (reducing) their range. In a study of North American tree species, more than half were contracting their ranges in response to climate change (Zhu, et al 2012). With a potential for an increase in maladapted species in tree populations and the potential for urban areas to exacerbate these stresses, it is important to incorporate new species that are showing promise into ongoing tree planting and then proactively monitor and select
high performing species for additional planting.
Climatic events (e.g., storms, drought, wildfire), disease or pest outbreaks, land use changes, and other stressors can severely affect the urban forest and the flow of benefits and costs over time. Increasing species diversity and tracking species performance can help managers determine suitable species and lessen the detrimental consequences in the event species are susceptible to changes in climate and other pressures in the urban environment.
Drought
The recent droughts in California have led to a decrease in urban trees throughout the state. Not only can drought be
the primary cause for a tree to die, but it can also
predispose trees to other stressors. Urban forest partners
and community members expressed concern that park
trees in San Luis Obispo have died from drought conditions
and also the need to focus future planting efforts on
drought tolerant species.
Pests and Pathogens
In some cases, pests or pathogens can result in significant tree damage or loss and/or be costly to manage. Involvement in the global economy, close proximity to major ports, and a highly
mobile human population increase the risk of an invasive pest or pathogen to San Luis Obispo.
Pests of greatest concern have already been introduced to the state or neighboring
communities and other pests or pathogens could foreseeably have a huge impact on the tree
resource. Urban Forest Services continually monitors the tree resource for emergent pests and
pathogens. When unknown diseases are discovered, the causal agents are identified by a local
lab and management is determined based on the results.
Invasive Shot Hole Borers and Fusarium Dieback
The polyphagous shot hole borer and the Kuroshio shot hole borer (Euwallacea sp.) are invasive beetles introduced from Asia. They are involved in a disease called Fusarium dieback, which is present in Southern California. The polyphagous shot hole borer was first found in Southern California in 2003 and now has established populations in Los Angeles, Orange, and Riverside counties. It has recently spread to San Bernardino, Ventura, and Santa Barbara counties, and in 2016, a single beetle was found and caught in a trap in San Luis Obispo County (University of
“Ideally, less water
intensive trees would be
great across the city.”
-Survey Respondent
Page 163 of 299
11 Urban Forest Resource
California, 2021). Urban Forest Services has not observed this pest in San Luis Obispo, but participates in the statewide invasive shot hole borer management program, coordinates with the regional CAL FIRE representative specializing in forest pathology and entomology, and stays up to date on what to look for and how to manage this pest.
The damage causes branch dieback, and over time can kill the tree (Eskalen et al. 2017). These beetles have the potential to colonize healthy or stressed trees and have a large host range consisting of more than 260 plant species. The invasive beetles feed on fungi that they carry into heartwood tissues of the tree. Some of the introduced fungi are tree pathogens that disrupt the flow of water and nutrients. Sometimes staining and gummosis can be seen around beetle entry and exit wounds, and typically cankers have formed at these sites. The beetles feed on the fungus rather than tree tissues (Umeda et al. 2016).
Citrus Greening
Similarly, citrus greening (Candidatus liberibacter asiaticus) is a bacterial disease spread by the Asian citrus psyllid. The disease causes bitter, hard fruit production, and is among the most concerning pests as it threatens the viability of California’s citrus crop. As citrus is an important agricultural crop, there are quarantines in place to protect the industry. Because of the lack of effective treatments, the typical treatments for non-agricultural trees are to destroy and dispose of material appropriately and treat trees with pesticides (Grafton-Cardwell et al. 2019). In San Luis Obispo, all incoming citrus trees are inspected by the county.
Sudden Oak Death
Sudden oak death (caused by the pathogen Phytophthora ramorum) is documented in many coastal counties of California including the counties of Monterey, Santa Cruz, and Santa Clara (California Oak Mortality Task Force, 2020). While primarily affecting coastal areas from Monterey up to the Oregon border, there is a possibility of the disease spreading south to San Luis Obispo (EDDMapS, 2021). Urban Forest Services has identified this disease as a threat. In susceptible hosts, the pathogen can become systemic and girdle trees as quickly as one year after infection (Daugherty and Hung, 2020). San Luis Obispo’s most abundant species, coastal live oak (Quercus agrifolia) is highly susceptible to sudden oak death and incurs high mortality rates upon infection.
Challenges and Opportunities: Resource Threats
• Selecting species of trees that will be resilient in a changing climate, such as selecting drought-resistant tree species that will perform well in dryer and hotter climates.
• Increasing potential for periods of prolonged drought.
• Existing and emerging pests and disease.
Page 164 of 299
Urban Forest Resource 12
Resiliency Strategies
Severe impacts on the urban forest are anticipated as a result of climate change, including increased management costs and loss of canopy from declines in overall tree health. Despite anticipated negative outcomes for trees and the urban forest, the urban forest can be used as a tool to adapt to climate change. Management strategies can increase resiliency in the urban forest and also contribute to the overall resiliency of a community. It is important to incorporate as many resiliency strategies as possible and strive to maintain a healthy urban forest to better address climate change and pest and disease threats.
Recommendations for UFSP Planning: Resource Threats
• Update/develop a comprehensive species palette, including key characteristics, such as
Size/height
Water needs/drought tolerance
Space requirements
Propensity to cause infrastructure conflicts
Fall color, flowers, fruit, etc.
Minimum planter size
Pest/disease resistance
• Collaborate with researchers for newly recognized species that are expected to perform well in the region/microclimates.
• Explore tree palettes in regions with similar and projected climate.
• Consider a policy requiring replanting a certain percentage of native and/or drought tolerant species.
• Continue to collaborate with local and regional experts (Extension, Universities/Colleges, Nurseries, Landscape Architects, Researchers).
Emerging pests/disease and management strategies/treatments
Species selection and diversity
• Partner with the SLO Climate Coalition on climate action initiatives that relate to the urban forest.
Threats to the urban forest
Contribution or support from the urban forest
• Ensure the urban forest is continues to be emphasized in future planning documents (e.g., Resilient SLO).
Page 165 of 299
13 Urban Forest Resource
In recognition of the urban forests’ role in mitigating the effects of climate change, in 2021 the USDA Forest Service published nine strategies to increase resilience in the urban forest and communities to climate change, including the following (Janowiak et al. 2021):
• Activate social systems for equitable climate adaptation, urban forest, and human health outcomes
• Reduce the impact of human health threats and stressors using urban trees and forests
• Maintain or increase extent of urban forests and vegetative cover
• Sustain or restore fundamental ecological functions of urban ecosystems
• Reduce the impact of physical and biological stressors on urban forests
• Enhance taxonomic, functional, and structural diversity
• Alter urban ecosystems toward new and expected conditions
• Promote mental and social health in response to climate change
• Promote human health co-benefits in nature-based climate adaptation
Strategy 1: Activate social systems for equitable climate adaptation, urban forest, and human health outcomes
Effective response to climate change will require collaboration. Strategy 1 highlights the importance of engaging the community and leadership as a means to help sustain the urban forest, respond to climate change, and invoke broader policy to meet environmental justice goals for the health of both trees and people.
The key adaptation methods or approaches include:
• Address socio-ecological systems in early, comprehensive response.
• Integrate urban forestry in climate planning and policy.
• Address climate and health challenges of disadvantaged communities and vulnerable populations.
The following are examples of how urban forest management can activate social systems for equitable climate adaptation, urban forest, and human health outcomes:
• Engage the Community in the Urban Forest — When a community recognizes the many benefits provided by trees, supports the urban forest, and engages in activities related to trees, the community is more aware of their responsibility in the care of public and private trees and the resilience of the urban forest to climate change.
• Share Common Goals and Collaborate with Urban Forestry Partners — Partner with other green industry leaders, neighboring communities, regional groups, nonprofits, businesses, utility and state agencies, and other municipal agencies to work together to support the urban forest and climate change response efforts.
Page 166 of 299
Urban Forest Resource 14
• Capitalize on Tree Planting Efforts to Address Climate Based Impacts — Communities of black, indigenous, and other people of color have been disadvantaged by racially motivated policies, like redlining. Early studies suggest that one of the impacts of such policies is fewer trees in areas where more of these groups live. Planting trees is hugely beneficial, but through the strategic planting of trees, not only can some of these disparities in canopy distribution be alleviated, but climate concerns can also be addressed.
• Create New and Expand Existing Urban Natural Areas — Promote greater species diversity, expand canopy cover and the urban forest through creating, restoring, and/or expanding the size of urban natural areas.
Strategy 2: Reduce the impact of human health threats and stressors using urban trees and forests.
The key adaptation methods or approaches include:
• Reduce extreme temperatures and heat exposure.
• Improve urban air quality conditions.
• Anticipate and reduce human health impacts of hazardous weather and disturbance events.
The following are examples of how urban forest management can be used to reduce impacts of human health threats and stressors:
• Achieve Optimal Canopy Cover — The benefits of trees are directly attributed to their canopy. To optimize the benefits of canopy, managers should seek to achieve optimal canopy cover and equitable distribution across a community. Use of accurate, high-resolution canopy data can approximate optimal canopy cover levels. By identifying canopy potential, managers can work with the community to set long-term canopy goals and promote the preservation of existing trees on private property and incentivize the planting of trees on private property.
• Reduce Urban Heat Islands — Urban heat islands contribute significantly to high
temperatures in urban areas and can result in consequences to human health.
Some of the effects of urban heat islands can be abated through the strategic
planting of trees to shade hardscapes (e.g., parking lots, streets, other impervious
surfaces).
• Create “Green Screens” — Exhaust from cars and trucks are a main source of air pollution (California Office of Environmental Health Hazard Assessment, 2021). Communities adjacent to major roads and highways are heavily exposed to air pollutants and noise. Planting trees and creating “Green Screens” near major emissions sources (especially adjacent to high-speed transportation corridors) and selecting tree species with specific traits for particulate capture can result in improvements in air quality (Janowiak et al. 2021).
Page 167 of 299
15 Urban Forest Resource
• Establish Plans and Funding Reserves in Case of Natural Disaster — A variety of consequences can result from severe weather events and changes in climate. The ability to adapt and recover from damages to infrastructure, property, community health impacts, and environmental contamination is critical to our way of life (Carter et al 2015). A disaster management plan is in place in the case of trees damaged during extreme weather events. The plan includes staff roles, contracts, response priorities, debris management and a crisis communication plan. Staff are regularly
trained and/or updated.
Strategy 3: Maintain or increase extent of urban forests and vegetative cover.
A healthy urban forest is more able to withstand stresses, including the direct and indirect
impacts of climate change. By increasing the extent of urban forests and canopy cover, the
benefits they provide and climate change mitigation functions they provide can be maximized.
The key adaptation methods or approaches include:
• Minimize forest loss and degradation.
• Maintain existing trees through proper care and maintenance.
• Restore and increase tree, forest, and vegetative cover.
• Sustain sites and ecosystems that provide high value across the landscape.
The following are examples of how urban forest management can support the maintenance and expansion of canopy cover:
• Provide Clear Guidance and Protections Through a Tree Ordinance — A tree ordinance provides enforceable guidance for adequate maintenance and protection of the canopy cover provided by significant trees on private property. With strong enforcement, the loss of individual trees will not result in significant losses to the overall canopy cover.
• Define and Protect Heritage Trees — Trees are long lived organisms and mature
trees provide the greatest benefits. Defining heritage trees as those trees that are
especially significant to the community promotes their protection and recognizes
the benefits of mature or unique trees, which can further promote canopy
protection and enhancement.
• Protect Trees During Development and Redevelopment — According to the USDA Forest Service, it is estimated 175,000 acres of urban forest was lost per year between 2009 to 2014 due to development. During the same period, pavement and other impervious surfaces grew by 167,000 acres each year (Janowiak et al. 2021). While space is limited in urban areas, redevelopment projects do not have to result in the loss of trees and tree canopy. By establishing tree protection measures and implementing protection requirements whenever construction occurs near trees, the loss of valuable canopy cover can be avoided. Further restrictions on development and/or acquisition of land for the purpose of preservation and/or
Page 168 of 299
Urban Forest Resource 16
creation of conservation easements on private land holdings can limit development and its effects on the urban forest.
• Follow a Comprehensive Tree Planting and Replacement Plan — With a comprehensive tree planting and replacement plans, the resources needed to plant trees and establish trees can be more efficiently and strategically used to meet canopy goals and to maximize potential benefits (i.e., planting large-stature trees where space allows, prioritizing growth and expansion of canopy to address canopy distribution inequities, planting trees at optimal distance and direction from building to offset carbon emissions from heating and cooling).
• Routinely Maintain Trees — When all community trees are proactively and systematically maintained on a cyclical basis, optimal tree health and condition are more easily achieved, which contributes to tree longevity and maximal benefits.
• Ensure Tree Care Meets Industry Standards — By ensuring that tree care is conducted by ISA certified arborists and meets industry standards, tree health is optimized. Improper pruning practices (e.g., “topping” or removing the tops of trees and reducing large branches to stubs) can be extremely detrimental to tree health and can lead to irreparable damage that can lead trees to be prematurely
removed.
• Establish and Use Irrigation to Combat Drought — All trees need water during times of drought. Droughts are occurring more frequently and for longer periods, which require planning to ensure that trees receive water during such periods. By installing efficient drip irrigation systems that are separate from turf irrigation or where not feasible, supplying water bags or scheduling hand watering trees will have some assurance that trees will receive adequate water.
• Plant Trees per Best Practices — By planting trees per best management practices
and post-planting care are followed trees have improved long-term outcomes,
which can reduce maintenance costs and maximize benefits.
• Set and Follow Minimum Soil Volume Requirements when Planting — In the urban environment, soil is one of the most critical environmental factors that contributes to street tree health. Trees have extensive root systems that grow beyond the spread of the canopy and can be more than 6.5 feet into the ground (Day et al. 2010). If a tree is provided with an adequate amount of uncompacted soil, then the necessary water, mineral, nutrient, and oxygen requirements are more
likely met and it will have a greater opportunity to grow for years to come and can
reduce costs associated with maintenance (pruning) and infrastructure damage
caused by trunk buttress flare and root expansion (Clark et al. 1997).
• Build Wildlife Habitat and Corridors — Strategically plant and/or preserve trees and tree canopy to connect with and/or bridge existing core canopy to promote ecosystem functionality and biodiversity and create wildlife habitat and corridors for the movement of birds, insects, and other animals.
Page 169 of 299
17 Urban Forest Resource
Strategy 4: Sustain or restore fundamental ecological functions of urban ecosystems
Climate change is projected to have negative impacts on the environment and in many cases is already. In urban environments, trees are a critical component of the ecosystem. Trees have numerous properties that make them natural tools for mitigating the many of the effects of climate change. By supporting trees, the health of urban ecosystems can be improved through lessening environmental degradation and reducing physical and emotional health incidents.
The key adaptation methods or approaches include:
• Maintain or restore soils and nutrient cycling in urban areas.
• Maintain or restore hydrologic processes in urban forests.
• Restore or maintain fire in fire-adapted ecosystems.
The following are examples of how urban forest management can support urban ecosystems:
• Sequester and Store Carbon — Trees sequester carbon throughout their lifetimes and store it in woody biomass. These carbon sequestering capabilities suggest that urban trees could be incorporated into overall greenhouse gas emission reduction and/or storage strategies. To maximize such carbon sequestering benefits, trees should be retained as long as possible and when they must be removed, to avoid
the release of carbon back into the atmosphere from decomposition, utilize the
woody biomass in the highest and best possible end-use to maximize carbon
storage capacity.
Strategy 5: Reduce the impact of physical and biological stressors on urban forests.
Climate change presents many challenges to the health of trees, including variations in
precipitation and extreme temperature shifts. With these changes, many trees that were once
successful in a local area may no longer be suitable.
The key adaptation methods or approaches include:
• Reduce impacts from extreme rainfall and enhance water infiltration and storage.
• Reduce risk of damage from extreme storms and wind.
• Reduce risk of damage from wildfire.
• Maintain or improve the ability of forests to resist pests and pathogens.
• Prevent invasive plant establishment and remove existing invasive species.
• Manage herbivory to promote regeneration, growth, and form of desired species.
The following are examples of how urban forest management can reduce physical and biological stressors on urban forests:
Page 170 of 299
Urban Forest Resource 18
• Establish and Maintain a GIS Based Tree Inventory— Comprehensive, GIS-based, current inventory of all intensively managed public trees to guide management, with mechanisms in place to keep data current and available for use.
• Follow a Current and Comprehensive Urban Forest Master Plan — Having an urban forest master plan provides long-term management goals for increasing community safety and preserving and improving the health, value, and environmental benefits of the urban forest and can even support efforts in response to climate change.
• Monitor Tree Performance — The inventory indicates the condition of trees and is used to identify underperforming or maladapted tree species. Trees are continually monitored for the condition and test species anticipated to be adapted to the future climatic conditions are incorporated and monitored. Managers have a sense of species that either should be continued or phased out over time.
• Fully Staff and Adequately Fund Urban Forestry Programs — Establish stable funds to cover the costs of proactive and reactive tree maintenance as well as staffing, administration, and programming. Stable funds can allow for consistent staffing to meet daily workloads and ensure access to necessary equipment and
vehicles needed so that the community receives a high level of service.
• Assess and Promptly Address Urban Forest Risks — Large, mature trees may be removed because they are perceived as a health or safety hazard, but the benefits these trees provide take hundreds of years to replace. While it is true that wherever trees are present, there is some potential risk to people and property, many of these risks can be mitigated. In many instances, removal of entire trees can be avoided, through proactive inspection and management.
• Follow an Integrated Pest Management Program — Use of Integrated Pest
Management (IPM) protocols can effectively address pests and diseases (Wiseman
and Raupp, 2016).
• Prepare for Wildfire — In recent years, wildfires have devastated many communities. With prolonged periods of drought and a changing climate, wildfire is likely to continue to be a threat to communities that neighbor the wildland urban interface. Developing wildfire preparedness plans is not only important for establishing community wide evacuation protocols, but also can assist in wildfire mitigation strategies.
• Build Drought Tolerance — The tree species that make up the urban forest each
have different requirements and are best adapted to certain environments. Drought
tolerant and native trees are represented in the inventory to help managers
minimize tree losses during and following droughts.
Strategy 6: Enhance taxonomic, functional, and structural diversity.
With highly mobile populations, the spread of pests and pathogens that can negatively affect tree and other plant health is an ever-growing concern. Pests and pathogens that are currently devastating tree populations in one part of the country now, can easily immigrate to other areas.
Page 171 of 299
19 Urban Forest Resource
Through enhancing species diversity and stratifying the age of tree populations, communities can reduce the likelihood of severe losses in canopy from pests, pathogens, or other stressors brought on by climate change.
The key adaptation methods or approaches include:
• Enhance age class and structural diversity in forests.
• Maintain or enhance diversity of native species.
• Optimize and diversify tree species selection for multiple long-term benefits.
• Maintain or enhance genetic diversity.
The following are examples of how urban forest management can enhance taxonomic, functional, and structural diversity:
• Diversify the Population of Community Trees — Industry leaders suggest that no species should represent more than 10% of a population and no genus should represent more than 20% of a population (Clark et al. 1997; Santamour, 1990). Managers should consider diversity (i.e., species, genera, and family) when planting new and/or replacement trees to reduce vulnerabilities to pests and pathogens and reduce the likelihood of catastrophic losses to trees and tree canopy (Janowiak et al. 2021).
• Strive for an Ideal Aged Tree Population — An ideally aged tree resource allows managers to allocate annual maintenance costs uniformly over many years and assures continuity in overall tree canopy coverage and associated benefits. Striving to achieve an ideal age distribution ensures that there is a high proportion of young trees planted to offset establishment and age-related mortality as the percentage of older trees declines over time (Richards, 1982/83).
• Provide Adequate Funding and Resources for the Urban forest — The community tree resource, just like other community infrastructure, requires consistent planning and maintenance. Climate change is likely to increase the
frequency of reactionary maintenance. By providing stable funding for urban
forestry, preventative maintenance can occur, which is frequently less costly than
reactive maintenance and prolong the lifetimes of trees.
Strategy 7: Alter urban ecosystems toward new and expected conditions.
Research is actively trying to understand the potential impacts of climate change. With climate change, local climate conditions are expected to shift. Models have been developed to project some of these changes and communities can evaluate these projections and begin planting trees that are anticipated to be more successful in future climatic conditions.
The key adaptation methods or approaches include:
• Favor or restore non-invasive species that are expected to be adapted to future conditions.
Page 172 of 299
Urban Forest Resource 20
• Establish or encourage new species mixes.
• Introduced species, genotypes, and cultivars that are expected to be adapted to future conditions.
• Disfavor species that are distinctly maladapted.
• Move at-risk species to more suitable locations.
• Promptly revegetate and remediate sites after disturbance.
• Realign severely altered systems toward future conditions.
The following are examples of how urban forest management can support urban ecosystems:
• Apply Climate Change Projections to Species Selection — Increasingly, cities are recognizing that shifts in weather patterns are likely to alter species habitat ranges and render some species less adapted to the region. Although there is no clear consensus on the future outcomes, some research has pointed to looking toward comparable cities thought to have a similar climate to future projections as a way to move forward. The current climate of a comparable city is known (Bastin et al. 2019) and managers make connections with colleagues in comparable cities and explore their species palettes. Experimental species are chosen based on climate projections, such as changes in temperature and precipitation. Strategies for climate adaptation include favoring species that are predicted to do well in climate models, encouraging new species mixes, and choosing species that are well adapted to weather events such as flooding, high winds, and other storm events (Janowiak et al. 2021).
• Remove and Replace Trees — Some species of trees are maladapted to the local climate or succumb to pressures brought on by climate change (e.g., saltwater intrusion, increased temperatures, etc.). Once species are identified to be unsuccessful, future plantings of the species should halt and existing trees be gradually phased out and removed.
• Fully Stock the Community Tree Resource — Municipalities are limited to planting trees in the public rights-of-way. If all vacant sites are tracked and as funding permits, planted with trees, then the contribution of public trees to overall canopy cover is maximized.
Strategy 8: Promote mental and social health in response to climate change.
Climate change is anticipated to severely impact human health and many health issues may exacerbate inequalities and disproportionately affect those with underlying health conditions.
The key adaptation methods or approaches include:
• Provide nature experiences to ease stress and support mental function.
• Encourage community and social cohesion to support climate response.
Page 173 of 299
21 Urban Forest Resource
The following are examples of how urban forest management can promote mental and social health in response to climate change:
• Share Information, Ideas, and Resources — Collaborative planning is important for effective communication amongst partners to plan for and respond to climate change stressors. Together, managers can communicate and collaborate to address the urban forests’ greatest vulnerabilities and select experimental species that may be best adapted to the future climate.
• Integrate Urban Forestry in Climate Planning and Policy — Trees have properties that make them especially useful in mitigating the effects of climate change. Wherever possible, policies and long-term planning for response to climate change should consider opportunities to support urban forestry programming.
Strategy 9: Promote human health co-benefits in nature-based climate adaptation.
Nature-based climate adaptation technologies, like trees, can not only mitigate the effects of climate change, but also promote improvements in human health.
The key adaptation methods or approaches include:
• Co-design large-scale green infrastructure and build systems to promote health.
• Provide micro-scale nature experience to promote health and healing.
The following are examples of how urban forest management can promote human health co-
benefits in nature-based climate adaptation:
• Considered Trees Essential Infrastructure — Prior to planting a tree, provide
adequate space for future growth of the tree (including space for the root systems)
and consider future impacts of trees with lines of sight and other critical
infrastructure and to avoid conflicts between trees and above or below ground
utilities. In many instances, structural pruning can mitigate conflicts with
infrastructure and avoid premature removal.
• Incorporate Trees into Stormwater and Other Green Infrastructure — Trees filter stormwater, cleaning and moderating the amount of water in urban areas. Urban forests can provide both cost savings and reduce pressures on engineered systems with urban area function in mind.
Specific recommendations for the City of San Luis Obispo for implementing and improving
resiliency strategies are noted in the sections where they apply.
Page 174 of 299
Urban Forest Resource 22
Page 175 of 299
23 Operations and Programs
Operations and Programs
San Luis Obispo’s urban forest is composed of both public and private trees within City limits and in the surrounding Open Space areas. Trees within the build environment, or in the urbanized area, require more management than trees within the City’s Open Space areas and other more natural areas. The Urban Forest Services program within the Department of Public Works is responsible for the maintenance of trees along streets, in medians, parks, and at City facilities. Urban Forest Services staff perform the following services:
• Maintenance of trees along streets, in medians, parks, and at public facilities
Proactive maintenance of trees in the downtown core
Accelerating maintenance for grid pruning to re-establish a maintenance cycle for all other rights of-way trees (contractor)
Reactive maintenance resulting from service requests or special requests (e.g., planting, pruning, watering) (in-house or contractor)
• Contract monitoring (grid pruning, removal, stump grinding, and planting)
• Commemorative Tree Program
• Service requests/citizen complaint and correspondence
• Safety and clearance for all public trees (including natural areas)
• Safety and clearance for private property trees that interfere with public rights-of-way
• Emergency response for all public trees
• Tree inspections, including new tree plantings
• Tree removal applications
• Enforcing the Tree Ordinance
• Development design review
• Heritage tree program
• Tree Committee liaison
• Coordinating with urban forest partners
• Community outreach and engagement
• Addressing hardscape/tree conflicts
• Supplemental watering
• Pest monitoring
“The City should have an
aggressive street tree
planting and maintenance
program.”
-Survey Respondent
Page 176 of 299
Operations and Programs 24
Services and Programs
Service Requests
Residents can submit service requests and report tree issues through a link on the City’s web page. The Public Works Department also has a central call line, but residents are directed to the online portal when possible. Urban Forest Services receives approximately 415 service requests each year. Most service requests are for pruning to address fallen or broken limbs or tree removal.
At any given time, there may be around 20 open service requests. Generally, staff review requests within 24-hours, but the time it takes to address the request depends on the situation. For example, downed limbs are typically addressed on the same day whereas requests for tree removals require an inspection, which can take as long as a week. If approved, trees will be removed within the
scheduled cycle or a property owner may pay for the removal at their own expense. The majority
of requests for tree removals are attributed to conflicts between trees and sewer lines. Residents
Staffing Level Changes
Historically, the urban forestry program has provided proactive maintenance to all community trees along streets, in parks, public rights-of-way, and at city facilities on an 8–10-year cycle with an in-house tree crew. The team was fully staffed with 1 city arborist, 3 urban forest service staff, 3 tree assistants, 1 annual contract arborist, and 1 arborist in the Community Development department who was responsible for design review.
Since 2019, staffing in the urban forestry program has dwindled. Attrition from retirements and transitions has reduced staffing from 8 members to 2. At current staffing levels (2 full time staff), Urban Forestry Services is limited to providing reactive maintenance for most community trees (excluding trees in the downtown core and watering).
In an effort to return to previous service levels and catch up on delayed routine maintenance, Urban Forest Services increased the use of contractors. Since the beginning of 2021, Urban Forest Services is having contractors prioritize areas known to have higher risk trees. San Luis Obispo is like many municipalities, where tree maintenance is increasingly being contracted out to reduce risk and reduce the physical demands on City staff. Despite staffing levels and a period of deferred maintenance, Urban Forest Services
staff exhibit extreme professionalism and are committed to identifying areas to make
progress on maintenance priorities and fulfill the responsibilities for the care of
community trees and the expectations for service.
“I appreciate how quickly a SLO
urban forest employee
responded when we had an issue
with a tree on the sidewalk near
the driveway to our house
(large, broken branch was
hanging so low that we couldn't
access our driveway without
possible damage to our cars).”
-Survey Respondent
Page 177 of 299
25 Operations and Programs
with old, cracked sewer pipes often experience issues when tree roots exploit cracks in search of water. Urban Forest Services requires images or video of the damage before approval of a removal request for any healthy tree that has roots growing into sewage pipes. As the City is concerned with stormwater intrusion, there is a voluntary program for sewer line replacement through the utilities program. This program allocates a set amount of funding to address this issue in specific districts that tend to experience the majority of cracked sewer pipes.
Tree Pruning
Urban Forest Services program’s primary objective is to maintain the estimated 20,000 trees along streets, in parks, rights-of-way, and at public facilities on an 8 to10-year pruning cycle, but
maintenance currently is largely reactive and staff estimates they are a full cycle behind (8 to10
years behind in maintenance). The Urban Forest Services program has contracted tree pruners
working to accelerate maintenance work to get back to a regular pruning cycle. With the current
maintenance backlog, inspections for trees only occur during routine maintenance or when staff
are in the field. Ideally, Urban Forest Services would conduct proactive, cycle-based maintenance
that corresponds to the maintenance schedule for other Public Works assets. The intent of these
studies and inventories is to provide the necessary resources to the program to properly
management the urban forest assets to the community’s expectations.
While the frequency of care and the levels of services have been reduced in most areas of the
community, downtown trees receive biannual maintenance for structural pruning, building
clearance, and signage visibility. Business owners are notified of pending work whereas residents are notified of this and all other maintenance through parking notices. If adjacent property owners wish to prune a tree outside of the Urban Forest Service’s maintenance schedule, the resident must first acquire permit and must employ an ISA Certified Arborist to perform the work.
Recommendations for UFSP Planning: Service Requests
• Clearly communicate which services Urban Forestry Services offers and the time it takes to provide the services in a future urban forest strategic plan.
Challenges and Opportunities: Service Requests
• Some community members use the hotline to call in situations that are out of the scope of services, taking up valuable time and resources.
• Service requests are submitted frequently because the majority of street trees adjacent to private property are not regularly maintained.
Page 178 of 299
Operations and Programs 26
Municipal Code 12.24.150 protects all trees within the City from improper pruning practices by requiring that all tree care follow industry standards. The primary focus for pruning may differ between city departments (e.g., safety, risk management, storm mitigation, utility clearance), but following industry standards ensures that all public trees are properly maintained. Stakeholders indicated some concern for tree pruning that occurs in natural areas where the primary focus is on quickly addressing safety and clearance issues. A future UFSP should reiterate the requirement to follow industry standards for all tree care and ensure that maintenance staff are
fully trained to meet these requirements. When private trees are damaged due to improper
pruning, the Urban Forest Services Program enforces the City’s Municipal Code and holds the
responsible parties responsible for violations. Despite this, not all trees are receiving quality care.
Challenges and Opportunities: Tree Pruning
• The pruning cycle is estimated to be one full cycle behind.
• Resources need to be augmented to meet community and organizational needs.
• Industry standards recommend trees be pruned on a 5 to 7-year cycle, but current maintenance is reactionary.
• Despite Municipal Code, maintenance on some trees does not follow industry standards including private property and natural areas where the primary focus is on safety and clearance.
• Inspections occur during the routine maintenance of trees in the downtown core, but most trees are not regularly inspected.
• All City trees should receive the appropriate maintenance complying with best management practices.
Page 179 of 299
27 Operations and Programs
Recommendations for UFSP Planning; Tree Pruning
• Use maintenance schedules to quantify resource needs for budget augmentation.
• Continue to use contract services to enhanced tree pruning and maintenance to promote the long-term health and vigor of the city's urban forest, as well as maintain public safety (per Strategic Budget Direction Report).
• Determine the amount of funding needed to maintain a fully stocked inventory, where all planting sites are filled.
• Ensure contract services are regularly evaluated to ensure work meets best management practices and standards.
• Ensure all public trees are maintained according to industry standards as well as Municipal Code.
Move toward a 6-year maintenance cycle to proactively maintain all rights-of-way trees using pruning grids to efficiently group routine maintenance.
○ Publish the grid pruning map and schedule on the City website to provide residents with information on when to expect routine service.
Continue to plan for the increased maintenance for species that require more frequent pruning in the downtown area as well as throughout the community (an estimated 20% of the current inventory).
Work with the Parks and Recreation Department to ensure proper pruning for trees in natural areas.
• Develop an annual work program (per Management and Performance Audit of the Public Works Department).
Use Department-wide work planning and scheduling systems.
Include tree planting and maintenance costs for trees planted in support the goal of planting 10,000 new trees by 2035 in partnership with ECOSLO and the community (per Strategic Budget Direction Report).
• Provide efficient and prescriptive maintenance to all city trees.
• Continue to work with Downtown SLO Ambassadors and the Downtown Foresters for tree well maintenance and tree pruning in the downtown core.
• Designate the urban forester or someone qualified within Urban Forest Services to set the level standards and policies for tree care.
Communicate the standards to all other City departments and partnering organizations tasked with managing public trees.
• Lead a campaign to support business licensing for tree care professionals and to educate private property owners on their responsibilities.
Page 180 of 299
Operations and Programs 28
Clearance and Visibility
Urban Forest Services provides clearance and visibility pruning for all trees interfering with the public rights-of-way. In the past, Urban Forest Services commonly provided safety and clearance
services to private trees interfering with public property. This is an auxiliary service that takes
away time and resources that should be directed toward the care of public trees because
Municipal Code designates private property owners responsible for addressing safety concerns
on their property. While the goal is to change this precedent, staff continue to provide safety and clearance services to private trees for increased safety and accessibility. Municipal Code calls for Urban Forest Services to provide a notice to property owners to abate clearance and visibility issues caused by privately-owned vegetation encroaching into the rights-of-way.
Heritage Trees
Heritage trees are landmark trees that stand out for their size, growth habit, or represent a unique species. Trees can be nominated for this designation by anyone in the community, but
trees must be approved by the Tree Committee and City Council before they are given this
designation and recognition. Once a tree becomes a heritage tree it is given the highest
preservation priority. According to Municipal Code, heritage trees can be any healthy tree within
City limits and the City is responsible for their maintenance. The current Urban Forest Services
policy is to inventory heritage trees, but designate maintenance responsibilities to the property
owner.
Urban Forest Services provides information about the heritage tree program for the City website
and features a self-guided tour of San Luis Obispo’s heritage trees, which includes the tree
location, photos, notable facts, and relevant history.
Challenges and Opportunities: Clearance and Visibility
• Urban Forest Services is upholding the past precedent to provide safety and clearance services to private trees.
Heritage Trees
• There is a discrepancy between the Municipal Code and the current Urban Forest Services policy around the maintenance of heritage trees.
Recommendations for UFSP Planning: Clearance and Visibility
• Increase public awareness of Municipal Code that designates private owners as responsible for private tree clearance and safety concerns.
Heritage Trees
• Modify Chapter 12.14.160 Heritage Trees to designate private property owners responsible for their maintenance.
• Consider a permit process to prune heritage trees.
Page 181 of 299
29 Operations and Programs
Tree Planting
Urban Forest Service’s tree planting efforts are primarily grant based and conducted by the longstanding nonprofit partner organization ECOSLO or contractors. Urban Forest Services does
not have an up-to-date inventory that includes available planting sites (i.e., stumps and vacant
sites) nor a tree planting and replacement plan. Staff direct tree planting to known vacant sites,
but with these tools, tree planting could be done in a more targeted, efficient manner. On
average, approximately 150-200 new trees are planted each year in vacant sites within public
rights-of-way and Public Works is responsible for planting approximately 50 trees each year and
relies on partnering organizations to plant the remainder. Urban Forest Services provides young
tree care to trees they plant, including watering. Mortality rates are generally low (<5%) and are
mostly attributed to gopher damage, lack of establishment, or vandalism.
ECOSLO is co-leading the City’s tree-planting efforts in
the rights-of-way. ECOSLO and its volunteers have been
integral to obtaining grant funding, planting, and establishment of 140 new trees since 2019. The organization works with several city departments, including Urban Forest Services, to identify planting sites and flag utility lines. For tree-planting requests in front of private property, ECOSLO encourages residents to choose a species from a limited list, based on the approved street tree list, grant requirements, and current availability. Planting is done by hand, which is difficult due to the hard, heavy clay soil. This is becoming a limiting factor for the organization because only a portion of volunteers are able to help with the physically demanding tree plantings. The City also relies on ECOSLO for watering and providing some structural pruning on the young trees planted through the partnership (during the first three years).
All tree planting on public property follows the City’s Tree Planting Standards as well as the Guidelines Specifications for Nursery Tree Quality, which is a document compiled by industry
professionals in the region. Nursery stock is monitored to ensure newly-planted nursery trees
are of high quality and to ensure any existing structural problems are identified and addressed
as quickly as possible (e.g., problematic branch connections or girdling roots).
“Tree planting requires continuous community engagement, volunteerism, and
stewardship beyond what our small City Urban Forest Services team can
provide.”
-Survey Respondent
“ECOSLO is a relatively
small nonprofit trying to do
BIG work.”
- Executive Director,
ECOSLO
Page 182 of 299
Operations and Programs 30
Community members are interested in caring for and expanding the urban forest. As a testament to this, community members initiated 10 Tall: An Initiative to Plant 10,000 Trees on Public Property in San Luis Obispo by 2035, which was introduced in the Climate Action Plan. Planting efforts are largely centered around low-cost, one-gallon container stock of native trees in City open space, creeks, and riparian areas. However, a subset of the 10,000 trees will be larger container trees and fill in vacant tree wells. This initiative is currently in the visionary stage, and Urban Forestry Services and ECOSLO are currently assessing their capacity to meet this
vision. Public Works is aligning staffing and funding levels with this vision, as they will ultimately
be responsible for the planting and maintenance of trees in the public-rights-of way.
In the benchmark community survey, eleven participants expressed the importance of tree planting and increased tree canopy at schools. While school properties present an opportunity for potential planting space, the San Luis Coastal Unified School District has been reluctant to expand existing tree planting efforts at facilities. Urban forest partners believe the barriers to tree planting at local schools are related to their capacity to provide tree maintenance and limited species availability through grant funded tree planting initiatives.
“Please look at our public
school's needs for trees.
Many of the school sites in
SLO can benefit from
more trees.”
-Survey Respondent
Environmental Center of San Luis Obispo (ECOSLO)
The nonprofit ECOSLO has been working to preserve and protect the beautiful natural areas of San Luis Obispo for more than 50 years. Since the organization’s humble beginnings as a group of college students taking it upon themselves to clean up city creeks, it has grown into being the area’s premier nonprofit for environmental advocacy. Among residents, ECOSLO may be most well-known for its creek-to-coast clean-ups, which historically have had considerable volunteer support and turnout. However, ECOSLO now works across many facets, including open space stewardship, county parks, green business development, sustainability outreach, and as of recently, urban forestry. Currently, ECOSLO is a team of six with two staff members primarily dedicated to the urban tree program. These staff members coordinate with numerous partners and, at any given time, work with approximately 40 volunteers.
ECOSLO is an incredibly valuable partner to the City, who has come to rely on ECOSLO for several projects, including trail work and tree planting. In 2019 a grant with California ReLeaf spurred what is now a large focus for the organization, planting trees in the urban areas of the community. Currently, ECOSLO is managing three tree planting projects
supported by CAL FIRE, the Tourism Business Improvement District Board, and Hardwood
Revitalization. In addition, the city has already relied heavily on ECOSLO in their robust tree
planting initiative. The natural areas and features of San Luis Obispo, so intensely treasured
by residents and visitors alike, would not be what it is today with ECOSLO! The partnership
between ECOSLO and the City of San Luis Obispo is a model example for progressive tree
planting partnerships.
Page 183 of 299
31 Operations and Programs
Commemorative Tree Program
The Commemorative Tree Program, managed by the Public Works Department, allows residents and groups to plant a tree in the Commemorative Grove at Laguna Lake Park in honor of
significant events or people. In the past, the Urban Forest Services provided planting,
maintenance, and replacement trees for those that were damaged or removed. Although not the
City’s responsibility, plaques are often damaged, vandalized, or removed. While the City has
long prided itself on offering this service, the program has been temporarily suspended due to the COVID-19 pandemic and other recent complications. Maintaining the Commemorative Grove is time-consuming and with the program's suspension, there is a considerable maintenance backlog. The City is currently assessing how to manage the program.
Challenges and Opportunities: Tree Planting
• A City-wide tree planting and replacement plan does not exist.
• Vacant tree wells are common and hard to locate because inventory records are not up-to-date.
• Existing stumps limit planting in available spaces.
• Replanting does not occur quickly.
• ECOSLO staff have informal training on tree care and rely on community partners for technical advice.
• Most young trees are not pruned by Urban Forest Services for the first 5-6 years.
• ECOSLO is limited in the number of trees they are able to plant.
ECOSLO does not have heavy machinery such as a truck, watering truck, or agar, therefore tree planting is done manually.
ECOSLO would have a greater capacity to plant trees if holes were pre-drilled.
• Due to visibility and safety concerns for volunteers, the ability to plant trees in medians is limited.
• Tree planting does not occur at local schools.
Commemorative Tree Program
• Many trees have suffered as a result of recent droughts and replacing them has been a challenge.
• The Commemorative Grove initiates a relatively high amount of service requests for trees that die, as each tree is tied to an individual or event.
• Plaques were installed on the ground, which presents difficulties maintaining grass and controlling weeds.
• The costs of maintaining the Commemorative Grove are not adequately covered by the current fee structure, as the fees only cover the planting cost.
• The current location of the Commemorative Grove hinders some functionality of the park.
Page 184 of 299
Operations and Programs 32
Recommendations for UFSP Planning: Tree Planting
• Create a planting plan.
Identify tree planting sites (per Strategic Budget Direction Report and Climate Action Plan).
Include the number of trees that need to be planted by Urban Forest Services, ECOSLO, as well as other partners (e.g., Tourism Business Improvement District Board) and Departments each year to support the initiative to plant 10,000 new trees.
Plan for the increased planting and maintenance efforts that will be taken on by Urban Forest Services as a result of the 10,000 Tree initiative.
• Quickly replant rights-of-way trees and replace infrastructure damaged by tree roots upon tree removal (not only those in wells).
• Set and follow policies to check that replacement plantings occur after removals.
• Ensure young trees receive structural pruning several times in the first 5-6 years to meet industry standards.
• Include shade trees as a cooling mechanism in new development (per Urban Heat Effects Policy in the General Plan).
• Engage with ECOSLO in strategic planning to determine what each party can manage in regard to future tree planting.
Consider pre-drilling holes with an agar for ECOSLO plantings or donating equipment for this use.
• Take over tree planting in medians, as Urban Forest Services can follow clear safety policies set by the City and the materials needed to divert traffic.
• In the planning process, explore ways to partner with schools to increase canopy cover.
Address schools’ concerns over maintenance with possible solutions.
Commemorative Tree Program
• Re-evaluate the program, consider ways to continue recognizing and memorializing significant individuals while addressing maintenance challenges.
Consider implementing a commemorative wall, bravado, and/or path with engraved bricks as memorials so that a tree is not tied to an individual.
• Work with the community and other City departments to determine if another location would be more appropriate for the Commemorative Tree Grove.
Page 185 of 299
33 Operations and Programs
Tree Selection
The City has a regularly updated (every 4-5 years) Street Trees Species List in the
Engineering Standards that guides tree
species selection. Urban Forest Services
is interested in expanding the tree list.
Local nurseries stock an assortment of species, but on occasion, some species are not available. Other species perform well in San Luis Obispo, but they are hard to source and therefore are not widely planted.
Right Tree, Right Place
To visitors and residents alike, the most recognizable trees in San Luis Obispo are the large ficus trees that line the streets of downtown. Many people have a fondness for these trees, as the urban forest is part of the culture in San Luis Obispo and these particular trees have been an integral part of downtown for around 50 years. These trees provide ample shade to the downtown area of San Luis Obispo, and undoubtedly contribute other benefits. While it is always unfortunate when one of these iconic ficus are removed, practicing “Right Tree, Right Place” can help avoid some of the current issues caused by the trees.
The practice of installing the optimal species for a particular planting site is known as the “Right Tree, Right Place”. This philosophy considers the effects of tree growth on existing and planned utilities, existing landscape, and other infrastructure. Factors to consider include, planter size, soil characteristics, water needs, as well as the intended role and characteristics of the species. By considering the long-term consequences of planting a particular tree in a particular place, conflicts and premature removal of trees can be avoided.
Some species, such as redwoods, are not suited for the local climate and climate change will likely exacerbate the problem. In the case of the downtown ficus trees, there are several causes of concern when considering “Right Tree, Right Place.” First, the ficus tree population is in a state of decline due to aging, which increases maintenance costs, safety concerns, the incidence of nuisance pests, and disease potential. Due to the large size of the trees and the root systems, sidewalk buckling and safety are ongoing issues. Furthermore, ficus trees drop fruit, which requires clean up, can cause slipping hazards, and commonly attracts flies and pigeons.
Ficus trees are also largely a monoculture in the downtown area, and species diversity is an important aspect and goal for the urban forest going forward. This is not to disregard their
importance and relevance to the San Luis Obispo urban forest. Urban Forest Services is
slowly replacing ficus with other species, aligning with the philosophy of “Right Tree, Right
Place.” Going forward, replacement and new plantings should consider different species to
increase species diversity and age distribution.
“I definitely would plant more trees in
my front and back yard if I know what
and where!”
-Survey Respondent
Page 186 of 299
Operations and Programs 34
Challenges and Opportunities: Tree Selection
• The species list should be expanded to include climate ready species.
• Species availability is dependent upon current nursery stock and some species the City, ECOSLO, community members, or grant funders want to plant are not available through vendors.
• Some species are performing well, yet they are not widely planted.
• Some species are not considered in future plantings because people rule out species because they are basing their opinions on the maintenance needs of overly mature individual trees.
• Planting the appropriate tree species for the available space to help to reduce infrastructure conflicts and nuisance fruit drop (“Right Tree, Right Place”).
• Providing ample shade downtown by selecting adequate replacement species during the phased removal of downtown ficus trees.
• Community survey respondents expressed a desire to incorporate more trees known to support wildlife.
• There is some desire to increase the amount of fruit and bearing trees in the community along pedestrian and bike paths and parks.
While fruit trees could provide residents with a nutritious source of food, consider the maintenance requirements associated with fruit and nut producing trees.
○ Increased maintenance to clean-up of fruits and nuts.
○ Potential to harbor agriculturally significant pests and pathogens.
Determine if trees will be pruned for fruit production.
Determine who is able to harvest fruit from public trees.
• Some trees are blocking historic and architecturally significant buildings.
Page 187 of 299
35 Operations and Programs
Irrigation
Trees in the public rights-of-way are rainfed and hand-watered when needed by staff with a City-owned water tanker. Through ECOSLO’s Adopt-a-Tree Program, called Tree Keeper, volunteers’ water their adopted tree using a 5-gallon water jug. Trees are watered with 5-10 gallons of water each week. ECOSLO and the City have an agreement where volunteers are permitted to access public water at the City’s Corporate Yard (non-potable well), at parks, or community gardens. Other strategies such as water bags, mulching, and informal neighbor adoption also provide water to rights-of-way trees. Urban Forest Services requests irrigation
systems be retrofitted in a limited number of locations with a significant amount of landscaping
impacted by redevelopment projects.
Trees in parks are irrigated with lawns on a watering schedule that is also conducive for the
trees. Per the General Plan, recycled water is used to irrigate park trees whenever possible. The
recycled water often has high levels of salt and chlorine, although park trees are not currently
experiencing problems. The San Luis Obispo Water Resource Recovery Facility is transitioning
the use of UV filtration technology and this problem will be resolved. It is likely more parks can
be transitioned to recycled water as distribution lines are implemented.
Recommendations for UFSP Planning: Tree Selection
• Expand the tree list.
Engage the Tree Committee and Cal Poly students when doing so.
Work with vendors, and collaborators such as Cal Poly, to get access to species that are not currently available.
Consider limiting the incorporation of tree species that require more frequent maintenance.
• Develop specific planting plans and palette themes for neighborhoods and
areas with different characteristics.
Engage the community in meetings to determine preferences for a downtown tree list and age succession of downtown trees.
• Identify and implement a strategy for a prioritized replacement schedule for downtown ficus trees in order to ensure the long-term preservation of the street tree canopy (per Strategic Budget Direction Report).
• Explore the use of plant growth regulators to decrease maintenance needs of downtown ficus.
Consider conducting case studies on other communities using growth regulators.
• Explore the use of anti-gibberellins to reduce nuisance berry drop.
• Promote species that provide wildlife habitat.
Page 188 of 299
Operations and Programs 36
Challenges and Opportunities: Irrigation
• Irrigation is not in place for current trees nor is there a plan for irrigation for new trees planted as part of the 10,000 Tree initiative.
• Changing water needs as a result of climate change and significant new tree plantings.
• Watering needs fluctuate and it is difficult to predict how much of Urban Forest Services staff’s time will be needed to water in any given year.
• ECOSLO has to frequently remind volunteers and City staff about their agreement for volunteers to access city water at parks and community gardens.
• Vigilant community gardeners are unaware of the agreement ECOSLO and the City have to access city water. This negatively reflects on the program and can be difficult for ECOSLO volunteers to navigate.
Recommendations for UFSP Planning: Irrigation
• Update the engineering standards to require irrigation in new tree plantings.
Create an irrigation installation standard for the 10,000 Tree initiative.
Include requirements for developers or property owners.
• Work collaboratively with the San Luis Obispo Water Resource Recovery Facility to implement irrigation whenever feasible.
During new and re-development.
During street renovations.
As new lines are implemented.
• Consider taking on some of the responsibilities to ensure newly planted trees in the rights-of-way are adequately watered.
• As the water facility is upgraded, include tree irrigation as part of this plan.
• Explore additional planter designs to help with stormwater management and bioremediation.
• Explore improvements to the watering agreement with ECOSLO.
Page 189 of 299
37 Operations and Programs
Tree Removal
Although there are some exceptions, tree removal is regulated for the majority of otherwise healthy trees within the City. Municipal Code 12.24.090 prohibits removing most any tree (public
and private land) without a permit and requires replacement trees to mitigate the loss of
canopy. Residents can submit a service request for the removal of dead or dying public trees.
Trees are inspected and if a tree needs to be removed, the tree will be removed during the
routine maintenance schedule, if it does not constitute a public hazard. Residents may pay for a
tree to be removed outside of the schedule. On average, less than 50 community tree removals
occur each year.
Per Municipal Code, all tree care
companies are required to be licensed.
Yet, some tree care companies are
operating without licenses and
participate in illegal removals. Urban Forest Services is responsible for the enforcement of the Tree Ordinance and is authorized to hold both the private property owner and the vendor responsible for violations of the chapter (including illegal removals). Many violations are reported by neighbors. All responsible parties are subject to fines and must mitigate the loss of the tree or trees through a mitigation plan.
Mitigation planting, as a result of the removal of rights-of-way trees, can be a slow process. For the relatively small portion of community trees removed from wells, City staff are responsible for mitigation planting and trees are replaced relatively quickly. All other mitigation planting is performed by contractors or ECOSLO. The City always meets, but more typically exceeds, the current mitigation for replacement by planting more trees than are required. In mitigation
Illegal tree removals are most commonly spotted and called in by neighbors. Even so, collecting
evidence and accessing policies make mitigation challenging. Many community members are
concerned that a large portion of mitigation plantings on private property do not occur at all.
Also, some residents are reluctant to plant trees because Municipal Code requires mitigation
planting upon removal. The City should educate the community about the options to plant for
mitigation.
Tree Removal Applications are required for the removal of private trees. The City Arborist will
review requests for removals and inspect trees and either approve or deny the removal request.
Residents and developers can appeal the City Arborist’s decision to the Tree Committee or
Community Development Director (Figure 4). Community members can review pending removal
permits on the City website and may submit an appeal within 10 days. Approximately 25% of the
City Arborists decisions on tree removal permits are appealed.
“The city requires a property owner to
get permission to remove a tree, requires
replacement planting, but never checks
to see that the replacement planting has
taken place.”
-Survey Respondent
Page 190 of 299
Operations and Programs 38
Figure 4: Tree Removal Flow Chart
In 2019, the Municipal Code was amended, which provided the Urban Forest Services and the Tree Committee with improved standards to review tree removal requests. Some subjectivity remains in the ordinance, but staff try to remain consistent in decisions for approval or denial of removal requests. The recent revisions improved the tree removal application process and Urban Forest Services is actively working to educate and assist residents and developers with these changes.
After removal, Urban Forest Services hires contractors for stump grinding. Occasionally,
contractors have not ground stumps adequately, which prohibits replacement planting until it
has been re-ground. To address this, the City recently modified their contract to include
guidelines that ensure stumps are ground to an adequate depth and to prepare the site for
future planting.
Debris and Wood Utilization
When public trees are removed, either the contractor disposes of the material or the in-house crew chips and repurposes the woody material into mulch. Mulch is used in parks or is offered to residents for private use. Residents can pick up mulch at designated public pick-up sites seven days a week. These sites are the City Corporation Yard, Laguna Lake, and Sinsheimer Park.
Page 191 of 299
39 Operations and Programs
To save on disposal costs and to give the community an opportunity to use wood produce from urban forestry operations, Urban Forest Services will occasionally leave usable wood adjacent to the rights-of-way, where residents can take the wood on a first-come, first-served basis. Until recently, a local mill that specialized in reclaimed wood processed wood from in-house removals. The wood produced from this operation was used to make custom furniture.
ECOSLO received the Hardwood Revitalization Grant, a CAL FIRE grant focused on planting trees that have an end-use for furniture. Likely, these trees will be harvested before they are mature, between 20 to 50 years from now. ECOSLO is responsible for their establishment and then these trees will become the Public Works Department’s responsibility. The City realizes that premature removals may become contentious, as community members have a strong desire to see healthy trees maintained to the end of their lifespan. In addition, trees removed as part of the Hardwood
Revitalization Grant will require milling rather than chipping, which is a different process than
other rights-of-way trees.
Challenges and Opportunities: Tree Removal
• In the past, Urban Forest Services has not always followed the Tree Ordinance when approving tree removal permits.
• Current staff are doing their best to follow these policies and provide clear documentation on their rationale, but there is still confusion for those applying for tree removal permits.
• Applicants or property owners call City staff regarding permit applications. These staff do not have access to information to update callers if the tree(s) in question have been approved or appealed.
• There is little to no code enforcement so many tree replacements that result from tree removals do not get planted and it can be hard to track down those involved in illegal tree removals.
• There is some subjectivity in Municipal Code 12.24.090, convoluting the process for tree removals, especially as to what constitutes as significant damage to infrastructure.
• Current policies allow for mitigation planting to occur offsite (another property or in the rights-of-way), but an alternative Tree Fund does not exist.
• Not all property owners understand the tree removal and mitigation planting process.
• Public outcry commonly occurs around tree removals, especially large mature trees in the downtown area and as a result of development projects.
Debris and Wood Utilization
• There is no plan in place for the removal of trees planted as part of the Hardwood Revitalization Grant through ECOSLO.
• A wood utilization program is not in place.
Page 192 of 299
Operations and Programs 40
Recommendations for UFSP Planning: Tree Removal
• Review and revise the ordinance to clarify what constitutes significant damage.
Conduct a PSA to promote proper tree care and business licensing within the City.
Consider testimonials from property owners.
• Use a variety of outlets such as newspapers, social media, and the City’s website
• Continue to consistently enforce Municipal Code when illegal tree removals occur.
• Increase mitigation requirements in cases where large stature, mature trees are being removed to incentivize retaining existing canopy. Explore alternative mitigation measures, such as funds to increase the size of the greenbelt.
• Have a system in place so partnering City staff can be up-to-date on information when applicants or owners call regarding if the tree(s) in question have been approved or appealed.
• Follow up to ensure tree replacement planting / mitigation is occurring.
• Explore creating a separate category on the City’s Tree Removal Application for tree removals associated with biofiltration planters.
• Explore creating a Tree Fund where mitigation fees as an alternative to tree planting.
• Explore an educational campaign outlining the City’s tree removal and planting policies.
Debris and Wood Utilization
• Coordinate with ECOSLO to determine ways to meet the Hardwood Revitalization Grant requirements while addressing concerns about premature removals.
Consider outreach events to educate the community on wood utilization.
Consider the phased removal of trees planted as part of the grant so their benefits are not all lost in a short amount of time.
• Consider implementing a wood utilization program to help meet carbon sequestration goals in the Climate Action Plan.
Collaborate with other City Departments and local mills.
Partner with contracting arborists to recycle/reuse wood from large tree removals.
Track carbon sequestration benefits provided by community trees in the urban areas.
Consider partnerships with local mills.
Page 193 of 299
41 Operations and Programs
Emergency Response
Urban Forest Services plays a significant role in the Public Works Storm Response Plan. Staff are involved in training and implementing the storm response plan each fall prior to the rainy
season. The storm response plan has thresholds to activate departments. Urban Forest Services
staff have a clear understanding of when to respond, where equipment is stored, and identified
locations to stage debris.
When emergencies occur, Public Works, Parks and Recreation, Natural Resources have a reciprocal relationship and help each other address tree maintenance across the community. All crews help address emergencies such as storm cleanup and patrol along streets, in parks, and
open spaces although Rangers are relied on more heavily and take more responsibility. If Urban
Forest Services is not able to address a call, Ranger Services seamlessly steps in. In addition,
Urban Forest Services rely on contracted crews for quick response.
Community Engagement and Outreach
The City’s website provides quick and accurate information for residents on tree care operations, current tree ordinance, the tree removal process, tree species selection, and frequently asked questions. By partnering with ECOSLO, the City is able to incorporate educational materials about the benefits of trees, the state of the urban forest, how to best care for trees, and how to volunteer which provides another avenue for community support of the urban forest.
Urban Forest Services perform outreach with local elementary schools highlighting the benefits of trees. They also hold an annual Arbor Day celebration that commonly includes tree talks by City staff, tree plantings by ECOSLO and the public, and a tree art contest for elementary school students in San Luis Obispo. Urban Forest Services had a bi-yearly presence at the Farmer’s
Market, both the week of Arbor Day and Public Works Week, where the booth for the urban
forest program is always one of the most popular. Some community engagement has been put
on hold due to the COVID-19 pandemic.
Challenges and Opportunities: Emergency Response
• Currently, there is not a specific training program or drill for emergency response duties.
Recommendations for UFSP Planning: Emergency Response
• Implement a training program or drill that covers staff responsibilities during emergency response.
• Include existing emergency response policies in the future Urban Forest Strategic Plan.
Page 194 of 299
Operations and Programs 42
As part of their tree planting partnership with the City, ECOSLO coordinates an adopt-a-tree program called Tree Keeper and engages a steady volunteer base. Volunteers are typically enthusiastic to help plant and maintain trees, demonstrated by their current volunteer base, exceeding their need for current work. In fact, some trees are receiving double watering in order to keep volunteers
engaged.
Cal Poly students make up a significant portion of the
volunteer base. In the past, Cal Poly students have interned
with the urban forest program, most commonly to conduct spot inventories. With an engaged
community, there is an opportunity to engage an even larger volunteer base for urban forestry
in San Luis Obispo.
Challenges and Opportunities: Community Engagement and Outreach
• Partnering organizations have expressed interest in increasing collaborative efforts to provide urban forest-related outreach and education as well as career development internships within Urban Forest Services.
• There is an opportunity to expand education and outreach at local schools.
• Community members are interested in volunteering and the online survey results revealed a potential to engage an untapped volunteer base.
• Community members filled out the online survey in great numbers and many want to be more engaged in the urban forest planning process.
• There is an opportunity to partner with the Parks and Recreation Department in facilitating urban forest outreach and volunteer events.
“My children's school
participated in an Arbor
Day art contest and tree
planting event.”
-Survey Respondent
Page 195 of 299
43 Operations and Programs
Development
Historically, a design review arborist was on staff in the Community Development Department. The design review arborist was engaged in every development proposal. This position no longer exists. Municipal Code requires developers to submit an arborist report with development proposals, but proposals for single-family residential sites are up to the discretion of the Community Development Department. If an arborist report is required, ideally, they are reviewed by the City arborist for accuracy. Due to staff attrition, a fraction of the proposals is currently being reviewed thoroughly by an arborist. This, coupled with the recent increase in growth/infill
development within the community, has led to many projects going without adequate
Recommendations for UFSP Planning: Community Engagement and Outreach
• Engage local schools.
Promote the benefits of the tree canopy in regard to student health and well-being and provide access to the wealth of information that support these benefits.
Develop tree care programs that students can get involved in, use tree planting as an educational tool for students.
• Work with ECOSLO to further circulate outreach and educational materials as well as volunteer opportunities.
• Promote the Adopt-a-Street-Tree volunteer program coordinated by ECOSLO.
• Continue to partner with local nonprofit and tree advocacy groups to support tree planting events.
• Continue to collaborate with Cal Poly to provide students with environmentally focused volunteer and internship opportunities.
Consider creating an annual internship with an arborist.
• Collaborate with Downtown SLO to provide outreach and educational programming around trees and the natural environment in the downtown area.
• Provide nonprofit partners with more clarity on the communication chain and what services are provided.
• Continue to explore ways to engage ECOSLO’s volunteer base and expand volunteer engagement.
• Provide additional opportunities for engagement during the Urban Forest Strategic Plan development process.
Organize another, more in-depth community survey.
Consider pop-ups at parks or local events.
• Explore support for moving large urban forestry-related events and volunteer coordination to the Parks and Recreation Department.
Page 196 of 299
Operations and Programs 44
consideration for existing trees. As a result, many large, mature trees are being removed for development projects. While replacement trees are required, they take decades to replace the benefits and the community is currently experiencing a loss in tree canopy.
Currently, developers are responsible for maintaining new tree plantings in the rights-of-way for 1 year and then these trees become the responsibility of Urban Forest Services. While many of these trees are in adequate condition, some trees were neglected and the City is responsible for these poorly established trees. The City should consider prolonging developer maintenance of new tree plantings to ensure proper establishment (e.g., 3-5 years) and mitigation if trees die.
State Housing Mandates
Historically, the City of San Luis Obispo has had a 1% growth rate cap set forth in the General Plan Land Use Element (Chapter 17.144 of Municipal Code). According to the City’s “Sustainable Growth Management” document, the last time this cap was reached was 2004. Since then, growth has remained under 1%, hovering around 0.5% from 2015-2020 (SLO City, n.d.). However, growth increased to 1.2% in 2021 and this growth trend is expected to continue with an increasing population and multiple new development projects in the City (Johnson, 2021). Starting as early as next year, the new State Housing Bills have potential to compound this growth as they modify single-family zoning to easier allow subdivisions and multi-unit properties.
In September 2021, several new bills were signed into law by Gavin Newsom to address the growing housing crisis in California. The most consequential of them may be Senate
Bill 9, which changes single family zoning to allow for subdivisions and multiple units on
single-family zoned property. These bills aim to address a severe housing shortage and
demand for affordable housing across the state.
• Senate Bill 8- extends the existing 2025 deadline for the ‘Housing Crisis Act of
2019’ by another 5 years, which requires local governments to increase density
in areas to offset ‘downzoning’ in other areas.
• Senate Bill 9- will allow most homeowners to build two homes or a duplex on single-family zoned lots through local ordinance or by ministerial approval. In some cases, the bill allows lots to be split to build an additional 2 homes for a maximum of 4 units for each lot. The bill sets forth the requirements local agencies can impose to approve subdivisions and multi-units in single-family zoned areas. This bill goes into effect January 1, 2022.
• Senate Bill 10- Streamlines the process for cities to upzone single-family
neighborhoods and build small apartments in transit and/or jobs-rich areas.
The bill provides the groundwork for cities or counties to pass ordinances
streamlining the construction of small apartments of up to 10 units on a single
parcel.
Page 197 of 299
45 Operations and Programs
The City uses the Engineering Standards in Capital Improvement Projects (CIP) and therefore follows the minimum requirements for the incorporation of trees in capital projects. Trees are incorporated, when possible, especially in rights-of-way improvements. Many times, the project budget is not adequate and more emphasis is placed on other infrastructure. In other words, trees are one of the first components cut. Trees are essential infrastructure that should be given consideration in planning through completion of Capital Improvement Projects.
Challenges and Opportunities: Development
• According to Municipal Code, not all development proposals require an arborist report, it is up to the discretion of the Community Development Department.
Lack of coordination between Urban Forest Services and Community Development in architectural review / planning in early stages of projects.
In many instances, development plans are not reviewed by an arborist and do not provide consideration for the preservation of existing trees (e.g., zero setbacks from the back of the sidewalk are not wide enough to allow for preservation).
• Lack of clarity on what trees need to be removed or what trees can stay during development.
• Trees in parking lots are being removed as a result of infrastructure conflicts and development.
• The community is undergoing a period of significant infill development and many of the recent projects have conflicted with the City’s priorities to preserve existing trees.
• New tree plantings are cared for by developers for a relatively short amount of time.
• Some of the trees planted by developers are in poor condition when Urban Forest Services takes over their maintenance due to inadequate maintenance and young tree establishment.
• Residents contact ECOSLO to request trees for mitigation planting.
• Urban Forest Services is tasked with inspection of tree protection measures during construction, but staffing restrictions limit their ability to do so.
• There are no standards for the replacement/planting of trees during CIP.
• Placing the same emphasis on trees as other community infrastructure.
In the online survey, community members were invited to provide comments on
their thoughts on San Luis Obispo's urban forestry program. There was
overwhelming concern about the recent developments causing the removal of
mature trees, more than 50 responses were related to this topic.
Page 198 of 299
Operations and Programs 46
Design
Trees in the Mission Sidewalk Districts have iron tree grates and tree guards that allow for pedestrians to walk over tree wells. Tree grates frequently require repairs, as the trunks and roots expand and create trip hazards. Urban Forest Services and Streets Maintenance address any maintenance needed to the grids. Sidewalk buckling also occurs regularly in the downtown
core as a result of tree root lifting. As such, maintenance also occurs regularly in the downtown
core, but in other areas of the community maintenance only occurs in conjunction with the
Pavement Management Plan (every 9 years). Some sidewalk maintenance projects require tree
root pruning. Any root pruning has to be approved by the City arborist and is then completed,
with little oversight, by the Streets Maintenance team. The team is not trained in urban forestry
and uses a stump grinder to prune roots, which is not consistent with industry standards and
can severely impact tree health.
Alternative designs are considered when possible. For
example, bricks are included when sidewalks cannot be
ground down. To allow for more space and water
infiltration, the City has implemented engineered soils
in the downtown core around carrotwood (Cupaniopsis anacardioides), a species known to frequently cause hardscape damage. While engineered soils increase water infiltration, other design options are available that hold more water (e.g., suspended sidewalks). As long-term improvement projects occur, the City should consider ways to expand the sidewalks and tree wells by implementing alternative designs to provide trees with adequate space, especially in the downtown core and parking lots.
“Encourage creative
designs so that existing
trees can be maintained
for environmental and
visual esthetics.”
-Survey Respondent
Recommendations for UFSP Planning: Development
• Ensure all development proposals are reviewed by an arborist in the initial planning stages to provide adequate consideration and space for existing and planned trees.
• Review and consider mature tree canopy growth.
• Explore a requirement for a longer establishment time for new tree plantings that are required as part of development.
• Require developers follow minimum (ANSI A300) maintenance standards.
• Ensure developers are responsible for reporting the status of their trees post-occupancy.
• Recognize trees are a critical infrastructure and plan to include them in development and new construction projects on public land.
• Ensure tree replacements after removals are not referred to ECOSLO.
• Explore incentives for retention of large trees in new construction.
Page 199 of 299
47 Operations and Programs
In the rights-of-way of the downtown core, temporary parklets have been installed to provide businesses with outdoor spaces during the COVID-19 pandemic. As these areas have been successful at keeping the downtown area safe and lively, the City is considering creating a permanent program for parklets. Tree maintenance has become more complex as a result of the parklets. If parklets become permanent, the City should work with the Downtown Association to explore their support in taking on some of the extra cost of this service.
The City is working on several infrastructure projects that have the potential to impact trees.
Several solar panel installation projects are underway including at the Bus Yard, Fire Station 1,
and Sinsheimer Pool parking lots. These projects do not interfere with tree canopy but should
initiate the development of internal policies on solar/tree conflicts as these are the first projects
of their kind. As planters for stormwater management, such as bioretention basins and
bioswales, become more common, Public Works may need policies that differ from typical street
trees. Trees incorporated in stormwater management infrastructure may require more frequent
maintenance or removal and replacement as their purpose is to enhance water quality and
reduce runoff.
“I am extremely grateful for SLO's urban forest. It is why I shop here rather
than in surrounding communities—all the shady parking.”
-Survey Respondent
Challenges and Opportunities: Design
• Implement alternative designs to benefit the trees, but also decrease trip and fall hazards.
• Where planters are designed with a focus on stormwater mitigation and/or bioremediation maintenance of stormwater infrastructure may require premature removal of trees.
• Internal policies around trees and solar collectors do not exist.
• Some homeowners’ associations within the community discourage tree planting.
• The Streets Maintenance program often uses a stump grinder to prune tree roots when they are disrupting sidewalks and potentially causing hazards, which does not follow current industry standards.
Page 200 of 299
Operations and Programs 48
Recommendations for UFSP Planning: Design
• Explore the use of pervious pavements and suspended pavements to increase the amount of uncompacted soil available to trees.
• Partner with Downtown SLO to implement designs that can help reduce hardscape conflicts involving large, mature trees in the downtown core.
• Perform case studies to explore the products/designs available for stormwater management and how they may work in San Luis Obispo.
• The Tree Ordinance should exclude requirements for tree removal permits within stormwater mitigation treatment areas.
Educate the public on the purpose of trees planted for stormwater mitigation.
• Assess parking lot sites and create larger tree wells whenever possible.
• Explore policies and procedures that fit the community’s vision around solar/tree conflicts in the Urban Forest Strategic Plan.
• Explore and identify reasons why some homeowners and HOAs don’t want trees in rights-of-way or on private property.
• Identify strategies to increase appreciation for the urban forest (e.g., more species choices, education, etc.).
• Explore policies and procedures around tree and solar conflicts in the development of an Urban Forest Strategic Plan.
• Update policies for tree root pruning to follow ISA standards.
Page 201 of 299
49 Operations and Programs
Safety
Tree care is a very dangerous occupation, frequently cited as being one of the top 10 most dangerous jobs in the US. In 2017, the Tree Care Industry Association (TCIA) reported that there
were 153 incidents, 92 resulted in fatalities and 63 were nonfatal in 2016. When Urban Forest
Services had more staff and a working crew, several incidents occurred and initiated safety
training around the topic, but most accidents are minor. Each division, including Urban Forest
Services, has a representative on the City’s Safety Committee which reviews accidents as they
occur and relays information back to their group.
Urban Forest Services staff are required to adhere to standards set forth by CAL OSHA (Group 3,
Article 12 Tree Work Maintenance or Removal), The American National Standard (ANSI Z133.1
Arboricultural Operations Safety Requirements and ANSI A300 Tree Care Specification), and ISA
Western Chapter of the International Society of Arboriculture pruning standards. In addition, all
staff are first aid CPR trained. Safety tailgates are reviewed every 2 weeks and staff complete
field assessments when they are in the field. In the past, Urban Forest Services was TCIA certified. Although they are currently not certified, they continue to supplement safety training with TCIA materials and participate in TCIA programs, such as the Aerial Lift Specialist Course.
Challenges and Opportunities: Safety
• Training on equipment and safety has been suspended for almost 2 years, but in the past Parks Maintenance, Urban Forest Services, and Ranger Services participated in joint trainings.
Recommendations for UFSP Planning: Safety
• Reenact training on equipment and safety.
Page 202 of 299
Operations and Programs 50
Page 203 of 299
51 Urban Forest Partners
Urban Forest Partners
Key urban forest partners were engaged to identify existing challenges and opportunities and to provide insight and recommendations to strengthen the existing urban forestry program structure. All engaged stakeholders were asked to respond to an initial survey and depending upon response and level of engagement, some team members were invited to participate in interviews for more nuanced discussions on maintenance, construction and development, planning, and preservation. All stakeholders provided important information about the current function of the Urban Forest Services program and potential staffing needs. Concerns, requests, and suggestions from all stakeholders were of primary interest and were provided full consideration in the development of the summary report.
Internal Partners
The urban forest in San Luis Obispo is managed by 4 city departments including Public Works, Parks and Recreation, Community Development, and Administration. Cross-departmental
cooperation is often necessary to achieving urban forestry goals. While there is a great deal of
shared appreciation, resources, and effort, coordination and communication among
departments is generally ad hoc. Regularly set meetings are not in place, but communication
avenues are open and staff have high rapport and a desire to support each other when possible.
The different departments recognize that helping each other results in shared success yet also
appreciate the value of their independence.
Page 204 of 299
Urban Forest Partners 52
Parks and Recreation Department
The Parks and Recreation Department is responsible for managing over 4,000 acres of open space with priority for maintaining viewpoints, building trails, outreach and education, and
safety and risk management. When needed, they conduct large-scale pruning for trees in the
Open Space areas. Urban Forest Services is responsible for maintaining trees in developed parks.
Parks and Recreation staff periodically help Urban Forest Services address emergency response for rights-of-way trees. Discussions with this department revealed the following challenges and opportunities:
Challenges and Opportunities: Parks and Recreation Department
• Currently, park tree maintenance is reactionary and does not meet the community’s expectations.
• More attention should be placed on adequate staffing and the resources needed to maintain park trees and mitigate hazards.
Recommendations for UFSP Planning: Parks and Recreation Department
• Plan maintenance cycles to include park trees.
• Develop and document inspection protocols for park trees to identify and mitigate structural concerns and risk.
Train all maintenance staff to recognize and communicate hazardous situations.
• Document mutual aid policies, including available resources.
Page 205 of 299
53 Urban Forest Partners
Community Development Department
The Community Development Department oversees many programs including development projects, building permits, code enforcement, affordable housing, and the flood control
programs. The Code Enforcement division is made up of Code Enforcement Officers and Code
Enforcement Technicians who provide information, investigate, and actively patrol for code
violations. When complaints are received for vegetation encroachment into the rights-of-way
Code Enforcement will make the initial vist, provide the propertry with a door hanger and pass along the violation to Urban Forestry. When violations are related to trees, Code Enforcement notifies Public Works who is then responsible for communication with property owners and ensuring the hazard is mitigated. Public Works is also responsible for enforcing the Tree Ordinance.
Challenges and Opportunities: Community Development Department
• The Public Works Department (Urban Forest Services) is currently tasked with enforcing the Tree Ordinance and code-related tree removals but the Department does not have the staffing capacity to adequately provide this service especially when violations occur on private property.
• Standards for tree removal policy during development are not always clear and objective.
• Existing trees are not always provided full consideration during the planning process for development proposals.
• The 2019 Senate Bill 330, Housing and Accountability Act, limits proposed housing developments to a total of 5 public hearings, putting the Community Development Department in a position where they do not want to refer a hearing to the Tree Committee but are required to in some cases to follow Municipal Code.
• The role and expectations for the Tree Committee are sometimes unclear.
Recommendations for UFSP Planning: Community Development Department
• Explore the feasibility for Code Enforcement to take on Tree Ordinance enforcement duties through an impact study.
• As development proposals are being planned, trees should be considered by all parties and if removals occur, plan for tree planting requirements and mitigation requirements.
• Create a study group that examines the optimal role of the Tree Committee in the development of the Urban Forest Strategic Plan.
• Explore modifications to Municipal Code 12.24.090 Tree Removal in relation to Tree Committee hearings.
• Create a policy and procedures guide for the Tree Committee and conduct training for new members.
Page 206 of 299
Urban Forest Partners 54
Fire Department
The San Luis Obispo Fire Department is a full-service
fire department that protects
residents and visitors from
fires, medical emergencies,
and other dangers. The department has an Insurance Services Office Public Protection Class 2 Rating, which is only achieved by 2% of fire departments in the country (City of San Luis Obispo Fire Department, 2021). In relation to trees, the department deals in fuel reduction, weed abatement, and enforcing code for hazard trees. It is rare, but when hazard trees are reported as fire hazards, the Fire Department will send out an inspector to see if the tree is on City property. If it is, the Public Works’ city arborist or contract arborist assumes responsibility for mitigation.
Challenges and Opportunities: Fire Department
• Fire response is not a consideration in the current disaster and preparedness response plan followed by the Public Works Department.
• Pinch points, or areas where if a fire were started it would spread into residential areas, are not all identified nor inspected annually for hazards.
Recommendations for UFSP Planning: Fire Department
• Develop/Update an overarching after-hours emergency response plan that includes existing plans for storm and flood response, and fire.
• Collaborate with the Fire Department to address trees that may pose fire hazards and identify and manage vegetation where infrastructure may need defensible space.
“The Urban Forestry Program needs to be part of a
City standing taskforce/working group with Fire
Department/Parks Dept/Public Works to conduct
wildland fire interface vegetation management
projects along open space boundaries, roadway
right of ways and city boundaries with areas such
as Cuesta Park to reduce ladder fuels and maintain
defensible space in the event of wildfire.”
-Survey Respondent
Page 207 of 299
55 Urban Forest Partners
Administration Department - Office of the City Manager
The City Administration Department is led by the City Manager who guides the day-to-day activities for the City. The City Manager reviews and sets standards for the urban forest, such as
planting, trimming, monitoring, carbon sequestration, and urban cooling. Serving as the
Department Head, the Deputy City Manager manages Finance, Human Resources, the City
Clerk’s office, the Economic Development Program, the Office of Sustainability, and Information
Technology. High level goals and visioning for the urban forest have largely been spearheaded
by the Administration Department.
Challenges and Opportunities: Administration Dept. — Office of the City Manager
• Although visionary documents call for robust tree planting efforts, plans have not been developed for the implementation of 10,000 Trees, including planting, maintaining, and ensuring tree survival.
• While City leaders have provided clear direction for increasing tree planting efforts, Urban Forest Services has concerns around the long-term maintenance of new trees as they are understaffed and not currently able to meet these expectations.
• The City intends to create a planning document for the urban forest such as a UFSP.
Recommendations for UFSP Planning: Administration Dept. — Office of the City Manager
• Create and facilitate greater connection between Departments involved in caring for the urban forest. Develop and document mutual aid policies, including resources.
• Ensure that planning for 10,000 Tree initiative includes funding for tree establishment, structural training, and long-term maintenance for trees planted in public space and rights-of-way.
• Partner with other departments and stakeholders to develop a comprehensive UFSP with clear action steps to achieve immediate and long-term goals.
• Create an Urban Forestry Core Team to aid in cooperation and communication among departments involved with the urban forest.
• Clear goals and plans in place for Urban Forest Services, partnering organizations, and nonprofits.
Include trees planted as part of the 10,000 Tree initiative in maintenance plans.
• Create and engage with a technical group, including CalPoly, ECOSLO, and other key partners for the development of the Urban Forest Strategic Plan.
Consider including sidebars with culturally significant trees and tree-related projects in the Urban Forest Strategic Plan (e.g., the “moon tree”, wood utilization projects, and growing Italian stone pine from seed for use in parks).
• Continue to promote the role importance of trees in long term planning, including the General Plan. Climate Action Plan, etc.
Recognize urban trees as critical public infrastructure.
Page 208 of 299
Urban Forest Partners 56
Administration Department — Office of Sustainability
The Office of Sustainability was created with the vision for San Luis Obispo to be a “thriving, resilient, and sustainable community” and works to achieve this through positive leadership,
collaboration, and policy development. The Office has several programs to support this goal,
including Natural Resources and Climate Action. Natural Resources oversees greenbelts, land
stewardship, natural history education, environmental restoration, and environmental mitigation.
These programs include habitat restoration and tree planting in open space. San Luis Obispo has ambitions to curb the effects of climate change through an aggressive tree planting initiative, which will largely occur in open space. The Natural Resources Environmental Restoration program focuses on creek restoration, tree planting, wetland and natural habitat improvements and considering these aspects in development processes.
Challenges and Opportunities: Administration Department — Office of Sustainability
• There is an opportunity to increase collaboration between the Office of Sustainability — Natural Resources and Urban Forest Services, as there is shared interest in the urban forest.
• Without a plan for the implementation or tracking tree planting as part of the 10,000 Tree initiative, Urban Forest Services is not sure how many trees will be planted in the built areas of the community.
• Collaborating Departments have ambitious goals around the urban forest and Public Works Urban Forest Services is not always included in visionary conversations.
• The transition from urban forest to open space is clear, but urban forest managers would like less distinction and more of a natural transition between urban forest trees and trees in open space.
Recommendations for UFSP Planning: Administration Department - Office of Sustainability
• Ensure all key Departments and organizations involved in managing the urban forest are engaged in planning and implementation for the 10,000 Tree initiative.
• Record details each time a new tree is planted for tracking purposes.
• Collaborate with the Office of Sustainability, Natural Resources to create a transition zone between urban forest trees and open space trees by using an appropriate mix of native species.
• Explore interdepartmental relationships and needs/opportunities for better communication and inclusive planning where appropriate.
Page 209 of 299
57 Urban Forest Partners
Public Works Department — Maintenance Operations (Parks)
Public Works provides safe mobility options and maintains public infrastructure and assets in San Luis Obispo. Public Works’ programs are divided between the Deputy Director, the City
Engineer Deputy Director, and Maintenance Operations. The City Engineers manage the CIP
Programs in addition to Transportation. The Deputy Director — Maintenance Operations
manages Facilities, Fleet, Parks, Street, and Urban Forest. The Parks division manages
approximately 550 acres of parks and a large number of park trees. The Parks maintenance staff monitor all trees in parks, provide clearance, and remove dead trees. When trees require service, they fill out a work order to be sent to Urban Forestry.
Challenges and Opportunities: Public Works Department — Maintenance Operations (Parks)
• Trees in parks are not maintained regularly, which has caused a backlog of maintenance and impacted tree health and aesthetics in parks.
• Over the past two years, Urban Forest Services has not been able to complete the work orders submitted by Parks Maintenance, creating a significant amount of additional work for Parks Maintenance staff to report and/or address, such as broken branches, branches blocking sidewalks, hangers, and litter clean up.
• San Luis Obispo’s parks are the unintended hosts of a consistent homeless population, which cause damage to park trees through improper pruning or destruction of young trees.
• Tree care is considered in Parks Maintenance Plans, although to a lesser extent than other infrastructure.
• Parks provide ample, irrigated space for trees.
• In most cases, the initial Parks Maintenance Plans underestimate the number of trees and amount of maintenance that will be needed in the future.
Recommendations for UFSP Planning: Public Works Department — Maintenance Operations (Parks)
• Inventory trees in established parks and include their maintenance in pruning cycles, work plans, and maintenance budgets.
• Continue working with the Parks Maintenance staff on trainings such as hazard identification, chainsaw safety, and basic tree pruning.
• Current and future growth/planning — Involve Urban Forest Services in new park plans and include trees in new development maintenance plans.
Page 210 of 299
Urban Forest Partners 58
Advisory Bodies
San Luis Obispo Tree Committee
The Tree Committee is an advisory body that provides recommendations to City Council and City Staff after reviewing tree-related proposals and requests. If the City Arborist cannot approve a tree for removal (non-development) the application is typically determined by the Tree Committee. Members of the committee may have some expertise in arboriculture and/or an interest in trees. The majority of the Tree Committee’s time is spent reviewing development proposals but they also engage in the appeal process around tree removals that are deemed a hazard and the nomination of Heritage trees. Commonly, topics include whether or not removal is warranted and/or if the proposed mitigation planting is adequate. The Committee reviews each topic and suggests recommendations on policies and regulations relating to the urban forest (e.g., invasive species management, specimen or rare species, overcrowding issues, mitigation requirements, planning to offset the canopy loss, and reasonably allowing for development). Currently, the Tree Committee is housed in the Public Works Department, which provides a staff member as a liaison/subject matter expert to the Committee.
Challenges and Opportunities: San Luis Obispo Tree Committee
• The roles, responsibilities, and authority of the Tree Committee are ambiguous.
• The Tree Committee is housed within the Public Works Department yet spends the majority of deliberations on topics relating to private trees.
• The community is undergoing a significant amount of infill development, partially related to an increased demand for housing, commercial sites, and the recent state Housing Mandate. Increasingly, the Tree Committee is being asked to review these development plans.
• The Tree Committee is the last governing body to review large development proposals. In most situations, by the time these projects are presented to the Tree Committee, they have already been approved and the Tree Committees recommendations may or may not be taken into consideration.
• There is no requirement for City staff involved with the proposal process to report back so that the Tree Committee knows whether or not their recommendations are being implemented.
• Currently, neither the Tree Committee nor the City Arborist serve as a liaison/ support for the Architectural Review Commission yet this Commission reviews projects that involve consideration for tree preservation and removal permits.
• The Tree Committee has a limited advocacy role for urban forestry budgeting through an annual report to the City Council that includes desired improvements.
Page 211 of 299
59 Urban Forest Partners
Recommendations for UFSP Planning: San Luis Obispo Tree Committee
• Perform case studies on the roles and responsibilities of Tree Committees in various model cities to help develop a clear purview and purpose for San Luis Obispo’s Tree Committee.
• Consider the amount of authority the Tree Committee should have in large development proposals.
• Clearly communicate the purpose of the Committee.
• Create guidance on roles and responsibilities and train new members.
• Consider changes to the organizational structure, specifically moving the Tree Committee to a Department with a larger focus on policies and regulations for the entire urban forest (e.g., the Office of Sustainability or Community Development).
• Make an ISA-certified arborist available to support both the Architectural Review Committee and Tree Committee for technical questions involving tree health and preservation strategies.
“I recently had to remove a tree on our
property. The process was good. The tree
committee members listened, the arborist
was helpful, and it was easy to see that the
City is working to maintain trees citywide.”
-Survey Respondent
Page 212 of 299
Urban Forest Partners 60
San Luis Obispo City Council
The San Luis Obispo City Council is a five-member board consisting of the directly-elected Mayor and four City Council Members. The City Mayor is elected to a two-year term, whereas
City Council Members have four-year terms. The City Council is the primary legislative authority
that sets policy, adopts ordinances, approves programs, appropriates funds, adopts budgets,
and approves contracts. The City Council outlines four overarching goals for San Luis Obispo,
including:
• Climate action, open space, and sustainable transportation
• Housing and homelessness
• Economic resiliency, recovery, and sustainability
• Diversity, equity, and inclusion.
Challenges and Opportunities: San Luis Obispo City Council
• The community and City Council are supportive of trees and understand that tree canopy is integral to the culture and character of the community.
• The budget for tree care is often one of the first to decrease during economic downturns.
• City Council Members are not always aware of the urban forest needs and the actions and associated budget required to meet visionary goals.
Recommendations for UFSP Planning: San Luis Obispo City Council
• Develop a robust and comprehensive Urban Forest Strategic Plan (UFSP) and clearly communicate the following:
Value and benefits of the urban forest
Community vision and direction for tree care and canopy cover
Long term goals and objectives, including long and short-term action steps and proposed timelines for meeting them
Maintenance standards for trees, including pruning cycles and industry BMPs
• Use direction from the UFSP to develop annual work plans in support of budget requests.
• Deliver an annual State of the Urban Forest Report to Council, outlining successes of the UFSP as well as challenges for implementation.
• Designate a liaison that can advocate for tree maintenance needs and goals.
Advocate for the importance of community trees and predictable, stable funding so that tree maintenance can meet community expectations.
Page 213 of 299
61 Urban Forest Partners
External Partners
Environmental Center of San Luis Obispo (ECOSLO)
ECOSLO is a 501(c)(3) nonprofit organization that serves the community of San Luis Obispo. ECOSLO was originally started in 1972 by Cal Poly students with the goal of cleaning up polluted creeks in the City. Now, ECOSLO is the premier organizer for sustainability, environmental advocacy, and environmental justice in the community. ECOSLO’s programs include various environmental cleanups, green business certifications, county park improvements, as well as urban tree planting.
The ECOSLO urban tree planting program started in 2019. It is made possible by grant funding from CAL FIRE and California ReLeaf and is largely volunteer supported. ECOSLO currently partners with the City to plant trees on city street parkways and on residential front yards. Tree care and maintenance is done through a volunteer adopt-a-tree program for which anyone can volunteer. The organization is interested in exploring additional opportunities to partner with the City in support of urban forestry.
Challenges and Opportunities: ECOSLO
• Communication and planning with multiple city departments on tree planting locations, tree removals, watering needs, and other maintenance needs is difficult for ECOSLO to navigate.
Under ideal circumstances, ECOSLO would ask for more support, but they limit their requests to Urban Forest Services’ support because they recognize that staff are currently overstretched.
• ECOSLO would like to explore a more clearly defined partnership with the city.
• Community members often reach out to ECOSLO for tree removals or replacement trees, but these requests have to be re-routed because these services are the responsibility of Urban Forest Services.
• ECOSLO is integral to the planting and maintenance of public trees throughout the community, a greater emphasis should be placed on continued
collaboration, clear communication, and joint strategic planning.
Recommendations for UFSP Planning: ECOSLO
• Explore existing partnerships with ECOSLO to optimize the relationship for both parties:
Create a central chain of communication and identify a primary contact from the city to coordinate with ECOSLO and facilitate projects.
• Engage with ECOSLO during the development of the Urban Forest Strategic Plan to discuss existing partnerships and future opportunities.
• Discuss and clarify expectations for the 10,000 Tree initiative, including specific planting sites and their intended planting date.
Page 214 of 299
Urban Forest Partners 62
Downtown SLO
Downtown SLO is a nonprofit organization formed in 2007 with the mission to promote an economically vibrant downtown in San Luis Obispo. Downtown SLO has several proclaimed
values, including creating community, promoting sustainability, prioritizing the environment,
helping businesses thrive and making downtown a beautiful place to visit. Partners of
Downtown SLO include fee-paying businesses, volunteers, nonprofit organizations, residents,
visitors and the City of San Luis Obispo. Many of the regular events in the downtown core are run by the nonprofit, including the Thursday Night Farmers Market and Concerts in the Plaza (Downtown SLO, 2021).
Downtown SLO hires Downtown Ambassadors, professional staff that clean and maintain tree grates or remove suckers and small limbs below 6 feet if they impede pedestrian paths. Historically, there has been a group of tree care volunteers called Downtown Foresters who have assisted with tree care in the downtown core.
Challenges and Opportunities: Downtown SLO
• There is opportunity for Urban Forest Services to further engage Downtown SLO in redevelopment projects, maintenance, and education and outreach.
• The upcoming downtown pavement project could be an opportunity to explore designs that promote large-stature shade trees.
• Large ficus trees provide a significant amount of canopy cover for downtown streets, but present several challenges.
Fruit and wildlife (e.g., birds, etc.) create aesthetic and nuisance conditions that are a concern for patrons.
Many of the trees are aging and a succession plan is needed.
Most agree that large shade trees are important to the character of downtown, but would like to explore other species options with an emphasis on reducing litter and pavement conflicts.
• As a result of COVID-19 and staffing changes, the Downtown Foresters have been less active than before.
“I think it is time to find a species of tree
to start replacing the ficus trees
downtown that are tearing up sidewalks.”
-Survey Respondent
Page 215 of 299
63 Urban Forest Partners
California Polytechnic State University (Cal Poly)
Located in San Luis Obispo, Cal Poly is a public university and one of the two polytechnic colleges in the California State University system. Cal Poly’s motto is “learn by doing,” hence many of the academic programs promote hands-on learning. Cal Poly offers more than 60 majors across 6 different colleges, many falling under the college of Agriculture, Food and Environmental Sciences. The college includes the major Forest and Fire Science that gives hands-on experience in forestry, as well as access to a 3,800-acre field laboratory site. Cal Poly has been recognized as a Tree Campus USA by the Arbor Day Foundation since 2014, and boasts the most diverse urban forest of any college campus in the nation (Cal Poly, 2020).
Cal Poly has previously been involved with San Luis Obispo’s urban forest. Previous projects and partnerships include work on the City’s approved tree species list, spot inventories done by student interns, and graduate work on urban forest planning. Volunteers from Cal Poly’s arboriculture class have also helped with city tree planting in the past.
Recommendations for UFSP Planning: Downtown SLO
• New downtown development and reconstruction projects should emphasize designs that support large-stature shade trees.
Upcoming downtown pavement project.
• Construction plans should include consideration for suspended sidewalks and/or plazas with pervious pavements to support large trees and canopies.
Consider areas of the Monterey District, Mission Plaza Concept, and Downtown District.
• Engage the community to clarify the vision for the future character and role of trees downtown.
• Create a species palette for downtown, including large-stature shade trees. Develop a successional planting plan to replace aging ficus.
• Engage with existing volunteers (e.g., Downtown Foresters) to formalize relationships and goals.
Challenges and Opportunities: Cal Poly
• Many opportunities to acquire and recruit Cal Poly students to become involved in the Urban Forest program through volunteering, interning, or other means.
• There are currently no formal programs or partnership agreements with Urban Forestry Services.
Page 216 of 299
Urban Forest Partners 64
Pacific Gas and Electric (PG&E)
Pacific Gas and Electric are responsible for the management of trees located under utility lines in San Luis Obispo. Municipal Code requires public utilities to acquire a permit before completing
any utility work that impacts adjacent trees. State law allows utility providers to remove or prune
trees as necessary to provide safe clearance. PG&E was not engaged in the development of this
report, but should be in future planning efforts around the urban forest.
Recommendations for UFSP Planning: PG&E
• Increase communication with PG&E.
Challenges and Opportunities: PG&E
• Urban Forest Services has established communication avenues with local utility providers, but in most instances, they do not learn about work occurring on public trees until after it is underway.
Recommendations for UFSP Planning: Cal Poly
• Engage with Cal Poly students and faculty to explore opportunities for students and programs to support the urban forest and gain valuable hands-on experience.
• Increase collaboration with Cal Poly through internship and volunteer opportunities.
Consider student help with expanding the species list, inventory management and updates, new tree plantings, and tree maintenance.
Engage forestry students in the UFSP planning process.
Page 217 of 299
65 Organizational Structure and Staffing
Organizational Structure and Staffing
Staffing
The urban forestry program has been undergoing organizational and staffing changes over the past 10 years. However, the most significant decreases in the staffing levels have occurred over
the past two years. Currently, Urban Forest Services employs one full-time Urban Forest
Supervisor (Interim) and one full-time Tree Assistant (Figure 5). The Department is currently
assessing staffing needs with consideration for the soon-to-be-developed Urban Forest
Strategic Plan, the 10,000 Trees initiative, and existing responsibilities.
Many of the organizational changes in the past 10 years have followed the 2011 Management and Performance Audit of the Public Works Department, a document that assessed the
organization’s structure and provided recommendations for the program (Management and
Performance Audit of the Public Works Department, 2011). The audit recommended the Urban
Forest Supervisor report to the Public Works Director and manage an in-house, 3-person crew.
Some of the asset management recommendations outlined in the report have not been
adopted by the urban forestry program and positions have not been backfilled as employees transferred, retired, or left the City. As a result, the program is understaffed and there is a backlog of maintenance needs and an anticipated increase in future workloads from infill development and increased tree planting. Urban Forest Services has fallen behind on the majority of maintenance tasks they are responsible for.
Figure 5: Current Staffing Structure of Urban Forest Services
Page 218 of 299
Organizational Structure and Staffing 66
Currently, Public Works has begun to use a contractor to perform the scheduled maintenance of area pruning. An in-house crew would continue to address reactive maintenance, training/structural pruning of young trees, specialized pruning, and emergency response. While contract crews can lead to greater efficiencies and reduced liability for the City, it is important to maintain an in-house crew that has a vested interest and knowledge of community assets and able to put trees into context with other city policies, goals, and infrastructure.
In addition to Urban Forest Services, other departments and teams have responsibilities for urban forest assets. Although this project did not include a full review of tasks or staffing in those other departments, several duties relating to the urban forest fit the purview and skillsets of other departments. For example, an Urban Forester position located in the Office of Sustainability or Community Development Department could act as a liaison to other
departments and enact broader goals and visions for the urban forest as a whole. Additionally, a
Volunteer Coordinator position placed in the Parks and Recreation Department could organize
outreach, community engagement and education for the urban forest program as these roles fit
the vision of this department. As the recommendations in this document address optimal
staffing for the urban forest and consider the addition of staff in other departments, it should be
reviewed and discussed by appropriate city staff to ensure agreement.
Challenges and Opportunities: Organizational Structure
• Positions have not been filled in the last 2 years and the program is severely understaffed.
Maintenance requests from other divisions are submitted to Urban Forest Services, but in most cases, there is not enough staff to complete the work.
Staff are not able to complete all of the assigned duties.
• Progress on the current high-level goals is not feasible for the Public Works
Department with the current staffing levels and budget.
• Maintenance and administrative roles are being carried out by the same individual, yet these roles require different skillsets and full-time attention.
• The city has not historically had an urban forester position focused on managing the entire urban forest resource (city assets) but has followed a model where a subset of individual trees are managed by multiple departments. This model does not facilitate a shared vision and allows for inconsistent standards in tree care and programming inefficiencies.
• While interdepartmental staff collaborate well and often coordinate for success, these relationships and overall program efficiency could be improved by documenting policies, responsibilities, and procedures. Coordination and collaboration with other departments responsible for shared visioning and care for the urban forest could be improved.
• Not all of the work provided by Urban Forest Services fit the vision of the Public Works Department.
Page 219 of 299
67 Organizational Structure and Staffing
Recommendations for UFSP Planning: Organizational Structure
• Explore the development of a comprehensive staffing structure that consolidates urban forestry services.
Collaborate with all urban forest service providers to identify optimal structure for consistent and efficient services.
Create an urban forester position to administer consistent vision and policy across departments and teams engaged in managing urban forest assets and is who responsible for the stewardship of the Urban Forest Strategic Plan and liaison with planning, development, Tree Committee, and City Council.
• Increase staffing levels, include the following positions (see Figure 6):
1 FTE Urban Forester (potentially located within the Administration Department — Office of Sustainability or the Community Development Department).
1 FTE or contracted Development Review Arborist managed by the Urban Forester.
2 FTE Arborists to create an in-house crew in the Public Works Department.
1 FTE Volunteer Coordinator (potentially located in the Parks and Recreation
Department).
Explore the need for additional administrative support to address permitting
and applications.
• Support and collaborate with all other departments responsible for the urban forest.
Page 220 of 299
Organizational Structure and Staffing 68
Figure 6: Staffing Recommendations
Page 221 of 299
Page 222 of 299
Organizational Structure and Staffing 70
Positions within the Public Works Department
1 FTE Senior Arborist. This is a lead arborist position that reports to the Maintenance and Operations Manager or another maintenance supervisor. This position should have the same duties as an Arborist but act as a crew lead at times.
1 FTE Arborist. Together, with the Senior Arborist these positions should create one functional in-house crew. At a minimum, the tree crew should contain one Senior Arborist able to tree climb and work from a bucket truck as well as two additional arborists. The tree crew should have the following duties:
• Respond to internal work requests.
• Address clearance and visibility of City owned trees.
• Conduct structural pruning in parks and city facilities, training pruning, and watering trees.
• Provide emergency response.
• Young tree care and watering.
1FTE Maintenance Contract Coordinator. In addition to other contract monitoring within the Public Works Department, this position provides oversight of the contract for cycle pruning and large tree removals.
• Oversee the contract for cycle pruning and large tree removals (ISA certification is preferred).
Positions outside of Public Works Department
Several key positions are needed in other departments to support urban forestry goals. Their placement is flexible and all partners should be involved in determining the optimal placement.
1 FTE Urban Forester (potentially located within the Administration Department — Office of Sustainability or the Community Development Department). This is a management level position with administrative and visioning duties, including the following:
• Liaison to other departments, City Council, the Tree Committee and Architectural Review Commission, work with partners and stakeholders.
• Advocate for the entire urban forest (not only the trees maintained by Public Works), set goals for canopy cover, sustainability, and climate action.
• Create and share policy, visionary documents, and an overall budget.
• Apply ordinances and evaluate trees.
• Conduct tree inspections and risk assessments when a hazard has been identified
(TRAQ qualification is preferred).
• Oversee a development review arborist.
• Participate in tree related outreach activities, support Parks and Recreation in the annual Arbor Day events.
1 FTE Development Review Arborist. This position should be managed by the Urban Forester have the following duties:
Page 223 of 299
71 Organizational Structure and Staffing
• Review all development proposals.
• Advise during development planning and review.
• Ensure contractors are following the Tree Ordinance and ANSI standards.
• Administer Removal Applications.
Respond to resident correspondences.
1 FTE Volunteer Coordinator (potentially located within the Parks and Recreation Department). This position should have duties that relate to education and outreach events that impact the entire urban forest, even trees cared for by Public Works. This would allow the City to expand formal volunteer opportunities and community engagement around trees.
• Conduct large outreach and education events, including those related to public trees managed by Urban Forest Services (e.g., Arbor Day).
• Further expand relationships with City Departments and partnering organizations caring for the urban forest.
Coordinate with Public Works and ECOSLO on an Adopt a Street Tree program.
• Lead volunteer efforts.
Equipment
Urban Forest Services has the equipment needed for a functional in-house crew. Staff have access to an aerial lift, truck, and chipper. Other equipment, such as the brush chipper and mowers, are shared amongst Departments. Once an organizational structure, services, and work
plans are agreed upon, Urban Forest Services can explore additional equipment needs,
potentially during the development of an Urban Forest Strategic Plan.
Challenges and Opportunities: Equipment
• Re-examine equipment needs once there is consensus on the appropriate organizational structure.
• The Parks Maintenance crew has one chipper truck and the City has a backup chipper truck. During winter storms, chipper trucks can be high in demand and not available, limiting clean up efforts to one crew.
• Several community survey respondents were concerned with the amount of fossil fuels being used to maintain the urban forest.
Page 224 of 299
Organizational Structure and Staffing 72
Contract Management
Approximately 95% of tree maintenance is currently conducted by contractors. In the current agreement, contractors are required to provide the City with tree maintenance forms that log
the maintenance performed each day. The following work is being contracted:
• Tree pruning
• Tree removal
• Stump grinding
• Emergency response
The ISA-certified Interim Urban Forest Supervisor has been working with the contractor to ensure maintenance meets the standards of Urban Forest Services, industry standards, and community expectations. The Public Works Department recently hired an in-house Maintenance Contract Coordinator who will be tasked with overseeing the tree maintenance contract as well as other contracted work within the Department. While this will help with the administrative aspects of the contract agreement, it is important that an ISA-certified arborist is involved in work planning and inspections of contract work.
Currently, the contractor has their own inventory and plans to integrate data on community trees to the City’s inventory database quarterly. Periodic data transfers do not allow the City to have a real time, up-to-date inventory. Ideally, contractors would update the City’s inventory.
Recommendations for UFSP Planning: Equipment
• Evaluate equipment needs.
Assess whether the City should replace the current water truck or fully contract out this service (also consider other young tree care duties).
Assess whether a stump grinder would be useful, or if this work will continue to be contracted out.
Assess whether the City should purchase an agar to aid urban forest partners in tree planting.
• Evaluate where redundancies would be useful.
• Explore the carbon use and capture that results from urban forestry operations.
Explore ways to reduce the amount of carbon (carbon footprint) produced in the management of the urban forest.
Page 225 of 299
73 Organizational Structure and Staffing
Challenges and Opportunities: Contract Management
• Contractors are not providing updates to the city’s tree inventory data, rather they are using their own internal system.
• Depending on the size of the in-house crew, Urban Forest Services may need to explore additional contract funding in the future.
Additional contract services will be needed to successfully complete the future increase in planting and maintenance expected as part of the tree planting initiative.
• The city recently transitioned contract monitoring to the Maintenance Contract Coordinator and although they are experiencing positive results, contract services are only sporadically monitored by a certified arborist.
Recommendations to follow up for UFSP Planning: Contract Management
• Require contractors to update the city’s inventory data as work occurs.
Confirm species
Update DBH as needed
Update condition as needed
• Explore additional contract needs for expanded services (e.g., watering, new tree establishment).
• Ensure a certified arborist is regularly monitoring/inspecting contractor’s work to avoid conflict of interest with maintenance contractor.
Monitoring can be done in-house (e.g., consider requirements for ISA certification for the Maintenance Contract Coordinator position) or through a contractor/company.
• Ensure contractors are completing and documenting tree inspections as they conduct routine pruning.
Document risk factors, health, and pest/disease concerns that cannot (or will not) be mitigated through maintenance.
• Continue to contract regular street tree maintenance / cycle pruning.
• Continue to implement contracts that:
Can be easily extended if the level of tree care provided by the contractor is satisfactory.
Clearly state the goals for contract services.
Require contractor adhere to all ANSI and ISA standards and BMPs for tree care operations.
Require that pruning be completed or supervised by an ISA certified arborist or ISA certified tree worker.
Page 226 of 299
Organizational Structure and Staffing 74
Funding
Funding for the urban forest program within Public Works is sourced from the General Fund and is expected to be $680,571 in FY 2020-2021. Preserving and maintaining the urban forest is one
of four strategic goals laid out for Public Works in San Luis Obispo’s 2021-2023 Financial Plan.
As part of this goal, the Financial Plan provides funding projections to meet the objectives of
completing the Urban Forest Strategic Plan, a comprehensive tree inventory update, creating a
database tracking system, and more pruning and maintenance.
The 2021-23 Financial Plan calls for an overall 35% budget cut to Urban Forest Services’ FY 2020-2021 budget, for a FY
2021-22 budget of $441,419. A large portion of this budget
cut is in staffing, the budget of which is being cut by 40%
due to the open positions that were not filled during the
Departments assessment/evaluation period. While there are
staffing constraints to the program, contract services are increasingly meeting needs for tree maintenance. In recent years, the City has increased funding to contract services which has lessened the backlog of service requests and made tree maintenance more proactive. The budget for contract maintenance services has increased from $60,000 to approximately $175,000. A portion of the funding allocated to contract services is also to support the development of an Urban Forest Strategic Plan.
Challenges and Opportunities: Funding
• Historically, Urban Forest Services has been underfunded.
• Securing steady funding for Urban Forest Services that does not fluctuate based on external factors and take future growth into consideration.
• City leaders and the community support the urban forest and may be willing to provide more financial support recommended maintenance and service levels.
Increase investment in proactive, preventative maintenance by exploring options to increase the frequency of pruning events for public street trees.
• Creating a sustainable funding plan for Urban Forest Services that forecasts and plans the budget for more than 2 years into the future.
• All of the current funding for the program comes from the General Fund.
“The city urban forestry
department is woefully
underfunded.
Subsequently tree
maintenance is not
completed in a timely
manner and the trees
suffer for it."
-Survey Respondent
Page 227 of 299
75 Organizational Structure and Staffing
Recommendation for UFSP Planning: Funding
• Create maintenance zones and work plans that includes all trees in the rights-of-way, streets, medians, parks, and city facilities and budget for their maintenance.
Plan for increased maintenance costs for proactive care on a 6-year cycle.
Plan for increased contracted or in-house work to support the robust tree planting initiative.
Plan to include the cost of maintenance for newly planted trees along streets, in parks, rights-of-ways, and at city facilities, including all trees planted by partnering organizations.
• Use the current assets, workloads, and anticipated growth in staff and new tree planting to determine what the future resources are needed.
• Create a long-term budget for the 10,000 Tree initiative and consider it in future funding projections.
• Develop a sustainable funding plan that looks further than the current budget cycle of two years.
• Partner with ECOSLO as conduit for donations to help support the urban forest and volunteer services.
• Explore implementing a Tree Fund that is used toward tree planting or urban forest conservation easements.
Page 228 of 299
Organizational Structure and Staffing 76
Page 229 of 299
77 Policy and Regulation
Policy and Regulation
Urban forest management operations are influenced by and subject to regulations, policies, and guidance from federal, state, and local direction. The following section provides a summary of the regulatory and guiding policies explored during this assessment of the urban forestry framework in San Luis Obispo. Additional regulations and policies may also apply.
Federal and State Law
Endangered Species Act
Signed in 1973, the Endangered Species Act provides for the conservation of species that are endangered or threatened throughout all or within a significant portion of their range, as well as the conservation of the ecosystems on which they depend. The listing of a species as endangered makes it illegal to "take" (i.e., harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, collect, or attempt to do these things) that species. Similar prohibitions usually extend to threatened species.
Migratory Bird Treaty Act (MBTA)
Passed by Congress in 1918, this Act defines that it is unlawful to pursue, hunt, take, capture, kill, possess, sell, purchase, barter, import, export, or transport any migratory bird, or any part, nest,
or egg or any such bird, unless authorized under a permit issued by the Secretary of the Interior.
The Migratory Bird Treaty Act can impact forestry operations during times when birds are nesting, which may delay work in order to avoid violating the MBTA.
Vegetation Management Standards
In California, all utility providers are subject to General Order 95; Rule 35 Vegetation Management (California Public Utilities Commission, revised 2012) and FAC-003-2 Transmission
Vegetation Management (NERC), which outline requirements for vegetation management in
utility easements. These requirements include clearance tolerances for trees and other
vegetation growing in proximity to overhead utilities.
California Urban Forestry Act
Section 4799.06-4799.12 of the California Public Resources Code defines a chapter known as the California Urban Forestry Act. The Act defines trees as a “vital resource in the urban environment and as an important psychological link with nature for the urban dweller.” The Act also enumerates the many environmental, energy, economic, and health benefits that urban forests provide to communities.
The purpose of the Act is to promote urban forest resources and minimize the decline of urban forests in the state of California. To this end, the Act facilitates the creation of permanent jobs related to urban forestry, encourages the coordination of state and local agencies, reduces or
eliminates tree loss, and prevents the introduction and spread of pests. The Act grants the
authority to create agencies and mandates that urban forestry departments shall provide
technical assistance to urban areas across many disciplines (while also recommending numerous
funding tools to achieve these goals).
Page 230 of 299
Policy and Regulation 78
Model Water Efficient Landscape Ordinance (MWELO)
To promote the conservation and efficient use of water and to prevent the waste of water, a Model Water Efficient Landscape Ordinance (MWELO) was adopted in 2009 and later revised in
2015. The Ordinance requires increases in water efficiency standards for new and retrofitted
landscapes through the use of more efficient irrigation systems, greywater usage, and onsite
stormwater capture. It also limits the portion of landscapes that can be covered in turf.
California Global Warming Solutions Act
In 2006, the California Global Warming Solutions Act (Assembly Bill 32) was implemented to reduce greenhouse gas emissions. Through this Act, California was the first state in the nation to
initiate long term measures to help mitigate the effects of climate change through improved
energy efficiency and renewable technology. California approached the goal to reduce
emissions to 1990 levels by 2020 through direct regulations, market-based approaches,
voluntary measures, policies, and programs. The 2015 update set targets to reduce greenhouse
gas emissions to 40 percent below 1990 levels by 2030.
California Solar Shade Control Act
Passed in 1978, California’s Solar Shade Control Act supported alternative energy devices, such as solar collectors, and required specific and limited controls on trees and shrubs. Revised in 2009, the Act restricted the placement of trees or shrubs that cast a shadow greater than ten percent of an adjacent existing solar collector’s absorption area upon the solar collector surface at any one time between the hours of 10am and 2pm.
The Act exempts trees or shrubs that were:
• Planted prior to the installation of a solar collector
• Trees or shrubs on land dedicated to commercial agricultural crops
• Replacement trees or shrubs that were planted prior to the installation of a solar collector and subsequently died or were removed (for the protection of public health, safety, and the environment) after the installation of a solar collector
• Trees or shrubs subject to city and county ordinance
Climate Adaptation Actions for Urban Forests and Human Health
In July 2021, the U.S. Forest Service published Climate Adaptation Actions for Urban Forests and Human Health, a comprehensive document that synthesizes information and recommends action steps for professionals and communities in expanding the role of urban forests for climate adaptation. The central component to Climate Adaptation Actions for Urban Forests and Human Health is the Urban Forest Climate and Health Menu. This menu provides information and ideas for urban forestry projects to improve climate and human-health related outcomes with a clear, organized step-based approach. The Urban Forest Climate and Health Menu is structured with three chronological steps going from conceptual stages to action stages to accomplish each of nine core strategies. These strategies are:
• Activating social systems for equitable climate adaptation, urban forest and health
outcomes
Page 231 of 299
79 Policy and Regulation
• Reducing impact of human health threats and stressors using urban forests
• Maintaining/increasing extent of urban forest and vegetative cover
• Sustaining or restoring ecological functions of urban ecosystems
• Reducing impact of physical and biological stressors on urban forests
• Enhancing taxonomic functional on structural diversity
• Altering urban ecosystems toward new and expected conditions
• Promoting mental and social health in response to climate change
• Promoting human health co-benefits in nature-based climate adaptation
This report solves the common challenge of synthesizing broad science-based information into actionable steps for communities. It can be used in developing new climate adaptation plans, to explore benefits and drawbacks of existing adaptation plans, and to generate discussions about community needs with regards to urban forest development.
Guiding Documents for the Urban Forest
Municipal Code
San Luis Obispo Municipal Code has seven titles that include provisions that impact trees, tree care, or the urban forest.
Title 1 General Provisions cross references Tree Regulations (Chapter 12.24) for the penalties applied for violating code.
Title 8 Health and Safety defines rubbish to include tree trimmings. Requires the removal of fallen or standing trees that are causing dangerous obstructions or preventing the flow of water in streambeds or other bodies of water.
Title 10 Vehicles and Traffic includes provisions for trees in visibility and clearance requirements. Requires reporting any accident that causes damage to trees. Designates oversize and overweight vehicle permit holders responsible for repairing any resulting damage to public property, including trees. Prohibits the permit holder from trimming city trees.
Title 12 Streets, Sidewalks, and Public Places prohibits any structures from encroaching on or coming into contact with street trees. Outlines the encroachment permit process, and trees can be included as obstructions. Provides protections to trees and tree-stakes/guards along creeks, riparian areas, and city properties adjacent riparian areas. Encourages tree and landscape plantings in parking lots as well as alternative designs, such as porous pavement, to retain existing trees in or near parking areas.
The Tree Ordinance, Chapter 12.24 Tree Regulations, establishes policies and regulations on the maintenance, removal, and preservation of trees. Explains the structure and duties of the tree committee. Requires a street tree list, major street tree list, and, when applicable, a tree planting plan for developments. Requires following standards and procedures for tree planting and maintenance.
Sets criteria for tree removal and explains the tree removal permitting and appeals process. Requires mitigation in the case of tree removal. Designates the City responsible for sidewalk
Page 232 of 299
Policy and Regulation 80
maintenance resulting from street tree conflicts. Designates the City responsible for maintaining trees on public property. Allows private property owners to hire certified professionals to prune trees or repair sidewalk damage out of the maintenance cycles, but at their own expense.
Prohibits hazardous trees on private property, outlines the abatement notice process, and designates responsibility to property owners for addressing hazardous trees. Requires public utilities to obtain a permit to maintain trees adjacent to utility infrastructure. Requires tree care contractors to have the appropriate licensing and accreditation and to follow industry standards.
Provides tree protections for physical damage, including considerations for roots. Prevents tree planting unless it is in accordance with the ordinance. Requires approval for the use of tree-stakes and guards. Specifies where slacklining is allowed on public trees and the necessary tree protections. Outlines penalties for violations to the ordinance.
Defines heritage trees and outlines their maintenance and protections. Designates the Public Works Department responsible for the enforcement of this chapter and addresses liability.
Title 15 Buildings and Construction adopts California Building Code and amends site plan requirements to include the location and size of all trees, indicating trees to be preserved or removed. Prohibits posting signs on street trees.
Title 16 Subdivisions requires plans and site maps for lot line adjustments to include all trees on the property. Considers trees in design standards for lots and street layouts. Allows for exceptions to the typical requirement for subdividing lots to reduce grading or tree removal. Considers street trees in street improvements. Requires subdividers to grant land easements for street trees if determined necessary. Defines “street tree”.
Title 17 Zoning Regulations requires trees as a pedestrian amenity in open space. Explains that creek setbacks are not based on individual trees. Explains that lot areas do not include the area within the dripline of heritage trees. Prohibits dead, decayed, infested (i.e., pests, including vermin), diseased, overgrown trees on private property that are a public nuisance. Ensures street trees are incorporated in street and right-of-way improvements when possible. Considers tree removal as an option in reasonable accommodation for disabled persons in land use and zoning regulations. Includes trees in the definition of “riparian vegetation”.
San Luis Obispo General Plan 2035
The General Plan is a document adopted by the City Council that considers the current, future needs as well as available resources and provides the following:
• Visions for San Luis Obispo’s future physical and economic development
• Strategies and specific actions that will allow this vision to be accomplished
• Bases for judging whether specific development proposals and public projects are in harmony with community goals
• Authorizes the design of projects that will enhance the character and safety of the community and preserve environmental resources
• Guides planning and implementing programs
The General Plan consists of eight elements, all of which pertain to the urban forest.
Page 233 of 299
81 Policy and Regulation
Land Use Element summarizes current community values to preserve the natural resources and control urban growth. Calls attention to the greenbelt surrounding the City and requires preservation of significant trees in the greenbelt. Highlights that the City works with partnering land managers to protect significant trees located outside of city limits. Recommends trees and groves of trees be used to differentiate the edge between developed areas and open lands.
Some of the Land Use Sustainability Policies have a central focus that directly relates to trees and tree canopy, including:
• Carbon sequestration (Policies: Climate Action, Natural Areas, and Green Space)
• Urban cooling and shade (Urban Heat Effects)
• Efficient landscapes with drought tolerant /native species, efficient irrigation, and captured rainwater (Sustainable Design)
• Long term tree planting program (Renew the Urban Forest)
• An up-to-date master tree plan (Urban Forest)
• Protecting the urban forest (Healthy Environment)
The Land Use element also calls to retain mature trees in the rights-of-way, cluster street trees along scenic roadways to conserve views, encourage fruit trees in lieu of lawns or other plants with high water use, and consider solar collector locations that minimize tree removal.
Circulation Element emphasizes creating streetscapes that incorporate street trees and considers tree planting, maintenance, and retention. Expresses a preference for native species with the desired characteristics. Addresses street tree placement along scenic roadways, and encourages clusters of street trees to still allow for views. Promotes pedestrian and bike paths that use trees as part of a buffer between pedestrians and traffic.
Housing Element supports neighborhood improvement projects, some of which incorporate street trees. Considers trees and other natural features when assessing the environmental constraints on residential development and estimated residential capacity.
Noise Element allows for landscape plantings as a way to create an attractive noise mitigation wall.
Safety Element presents policies and programs to address hazardous trees and emergency response.
Conservation and Open Space Element describes San Luis Obispo’s natural resources and emphasizes the importance of open space for wildlife habitat and corridors. Notes that trees are an essential component of the habitats the City aims to preserve and expand (i.e., oak woodland). Many of the goals, policies, and programs covered in this element impact trees, including the following:
“Significant trees, as determined by
the City Council upon the
recommendation of the Tree
Committee, Planning, or
Architectural Review Committee, are
those making substantial
contributions to natural habitat or to
the urban landscape due to their
species, size, or rarity.”
-Conservation and Open Space
Element of the General Plan
Page 234 of 299
Policy and Regulation 82
• Protect significant trees
• Continue the City’s Heritage tree program
• Incorporate native plant species in landscapes
• Minimize habitat disturbance during development, emphasize soil conservation
• Follow integrated pest management practices to avoid the use of environmental toxins
• Engage in area-wide planning efforts around environmental conservation (e.g., Habitat Conservation Plans, U.S. Endangered Species Act)
• Participate in environmental review
• Incorporate trees around pedestrian and bike paths
• Preserve and expand ecotones, wildlife corridors, and native vegetation
• Require creek corridor setbacks that allow for riparian habitat, including trees
• Engage the Tree Committee when implement tree preservation and planting programs
• Promote wood reutilization through mulching, milling, or pulping
• Support protected species and the conservation strategy (e.g., the conservation strategy for monarch butterflies is to conserve groups of trees)
Parks and Recreation Element explains the existing park facilities. Mentions trees as amenities in some of the City parks and considers landscaping a basic element of the parks. Recommends acquiring new parkland, developing new parks, and increasing connectivity between parklands. Highlights community and volunteer participation in park projects.
Water and Wastewater Element calls attention to the use of recycled water for irrigating landscaping in parks, streetscapes, and medians as well as some types of landscaping on private properties (e.g., homeowners associations, commercial, industrial, and business areas). Introduces other water efficiency programs.
Climate Action Plan for Community Recovery
San Luis Obispo’s Climate Action Plan sets goals to reach carbon neutrality by 2035. During the development of the Climate Action Plan, community workshops identified updating the City tree
list to focus on native species. The Plan is organized into 6 pillars, one of which is centered
around the urban forest.
Pillar 6: Natural Solutions focuses on ways to increase carbon sequestration. This pillar introduces the City’s plan to develop their first Urban Forest Strategic Plan to guide tree maintenance and planting. It also introduces 10 Tall: An Initiative to Plant 10,000 Trees in San Luis Obispo by 2035 and supports this initiative’s goals to plant and maintain 10,000 new trees by 2035. Although not a current goal, the City is looking into using the urban forest and other carbon sequestration tools as carbon credits to offset greenhouse gas emissions.
This Pillar of the Climate Action Plan recognizes the urban forest for its contributions in providing residents with benefits to mental health, cooling, stormwater management, watershed health, and increased property values. It also highlights the role of the urban forest in
Page 235 of 299
83 Policy and Regulation
supporting local economic development through job creation. The community partnerships and volunteer networks currently in place to help obtain urban forestry related goals are documented.
This pillar sets the City’s intentions to continue routine tree maintenance and emergency response for the current 20,000 trees in the inventory as well as the anticipated 10,000 new tree plantings in existing vacant sites, open spaces, riparian areas, and parks. In total, the Plan estimates 10,670 trees will be planted on public and private property. Another priority is riparian restoration with a focus on native tree planting, the suggested species composition is included. It calls for the use of an inventory management system to track progress.
This pillar includes equity considerations to identify the populations most vulnerable to extreme heat and flooding and then use the urban forest to increase the benefits from trees in areas with vulnerable populations.
2021-23 Financial Plan
The Financial Plan outlines the City’s two-year plan and the associated budget allocation for core services and programs. In the current Financial Plan, the City Council, guided by community input and advisory bodies, chose four areas to address the highest priority goals, these include:
• Economic Recovery, Resiliency & Fiscal Sustainability
• Diversity, Equity, & Inclusion
• Housing & Homelessness
• Climate Action, Open Space & Sustainable Transportation
The Financial Plan focuses on considering the financial resources needed to be successful in implementing the goals adopted in the Climate Action Plan (e.g., carbon neutrality, preservation of open space and the urban forest, and resilience planning). Tracking the number of public trees that are maintained is included as a performance measure.
The Financial Plan also outlines the operating budget for General Fund programs that are needed to continue Public Works operations, such as annual maintenance to the urban forest. The staffing levels are reported, showing the Urban Forest program has lost staff (full time and supplemental employees) in recent years, but contract services have increased.
Engineering Standards
Inspections at construction sites to assess progress also include an assessment for proper tree protection.
Tree Protection Provides standards for tree protection during construction, including details on protection fences, when it is appropriate to prune or attach something to trees being protected, criteria for excavation, grading, trenching, and boring, and tree protection and monitoring plans.
Includes criteria for street trees and tree wells in the design standards for roadways. Mentions permeable pavement as a way to increase aeration and water for tree roots in parking areas and alternative, compact designs are allowed if it may result in saving a tree.
Page 236 of 299
Policy and Regulation 84
Provides standards for bioswale designs with and without trees. Includes the street trees master list and street trees major lists. Illustrates and describes standards for tree wells and alternative tree well covers.
Street Tree Planting Instructions and Requirements Illustrates and describes expectations for tree planting, including tree quality, backfill material, tree size, type of tree, and planting location, and materials (e.g., stakes, mulch, and guards). Requires inspections of the hole dimensions prior to planting as well as the planted tree. Illustrates and describes standards for installing drip irrigation and tree bubblers. Specifies using mulch at the base of trees.
Management and Performance Audit of the Public Works Department
The Management and Performance Audit categorized improvements to the Public Works Department into six categories, all of which include recommendations that impact the urban forest including the following:
• Accountability focuses on clear and transparent direction. This category has broad recommendations that relate to the urban forest, such as redirecting resources to infrastructure maintenance and preservation as well as developing work planning and scheduling systems.
• Asset Management calls for a better understanding of community resources, such as their condition and performance of the community tree resource.
• Maintenance Management recommends implementing an information system that can be used to track the inventory of all infrastructure and work activities as well as setting annual work programs.
• Administrative and Management focuses on implementing structural changes to the department to increase efficiency, including changes to staffing levels and position responsibilities. Specific recommendations are included for the Urban Forestry Division.
• Preventative Maintenance of the Infrastructure recognizes the long-term benefits of preventative maintenance to increase the useful lifespan of assets and reduce overall costs.
• Cost Effective Service Delivery highlights the cost savings associated with redesigning staffing levels and duties, vehicle needs, and implementing managed competition for contract work.
Estimating Urban Canopy Cover in San Luis Obispo
The tree canopy was determined for the urban reserve, which includes all of the core-built features within the City boundary. This assessment uses 2012 aerial imagery to estimate the tree canopy. When breaking down tree canopy by land use type, it showed that office properties and residential areas have the highest canopy cover. Tree canopy varied slightly between the residential density levels. The assessment found that tree canopy is not equally distributed throughout the City and tree canopy varies nearly eight-fold between the land use categories with the highest (Office) and lowest (Business Park) categories.
Page 237 of 299
85 Policy and Regulation
San Luis Obispo Creek Stormwater Resource Plan
Summarizes what is known about the watershed and recommends ways to improve watershed health. Tree canopy is mentioned as a non-quantifiable benefit to buffer and shade aquatic
habitats. Tree planting is recognized as a way to control stormwater flow and water quality.
Green streets that increase water capture and reuse are identified as a priority need. Several methods to increase water infiltration are listed including: bioretention, pervious pavements, downspout disconnection, infiltration basins, and dry wells. Sets criteria to prioritize for green streets projects (considers feasibility and ranks planned projects, public visibility, contributing runoff and pollution, infiltration feasibility, proximity to critical habitat, and existing drainage problems). Maps areas that generate greater stormwater runoff, which are largely areas with a high proportion of roads.
Parks and Recreation Blueprint for the Future 2021-2041
Guiding themes for the SLO Parks and Recreation Blueprint plan include Stewardship and Sustainability as well as Inclusion and Access. As part of the ‘Stewardship and Sustainability
goal,’ Parks aim to become carbon neutral and incorporate ‘low-allergen plants and trees’ (SLO
Parks). Additionally, as part of the ‘Inclusion and Access’ theme, Parks aims to create equal
access to green spaces for all. One of 25 new park projects, the Margarita Area plan, includes
park trees. At a 2018 pop-up event to gain community input, participants voted for trees as
being an important feature to be included at future parks. Trees were emphasized as important
to creating shaded play areas at future parks, as they not only contribute shade but a ‘distinctive
identity and sustainability’ (SLO Parks.) The park blueprints highlighted issues and future planned improvements for each park in San Luis Obispo. Minimal shade was listed as an issue at both Meadow Park Center and Laguna Lake Park. Shade could be increased at these parks with tree planting.
The Blueprint document sets goals to:
• Prepare a tree inventory for all the parks to inform future planting, maintenance needs, and budget
• Develop a master tree list to accommodate for climate change, allergen levels, and
drought tolerance
• Develop a new work order management system in collaboration with Public Works to assist staff in remaining up to date on maintenance tasks of various frequencies. This includes managing natural assets like trees.
Resilient SLO
Resilient SLO is currently in the planning phase and this planning document aims to increase resilience to the impacts of climate change.
Additional Planning Documents
In addition to these guiding documents, the City has developed Specific Area Plans that embed the principles for tree maintenance that are presented in other guiding documents, such as the General Plan and Engineering Standards.
Page 238 of 299
Policy and Regulation 86
Higuera Street then and now.
Page 239 of 299
87 Benchmark Community Survey
Benchmark Community Survey
An online survey was created for an initial assessment of community understanding, appreciation, and future vision for San Luis Obispo’s urban forestry program and urban forest. The survey was available on the City’s website, announced at City Council meeting and also advertised with signs at parks and trailheads. Responses were collected between September 22 and October 21, 2021. In this one-month period, the online community survey received 644 responses from community members. The survey included 9 questions about community members’ views on tree benefits, education and outreach, urban forest program operations, and
preferences for future plantings. The survey offered participants to expand on their answers and
provided space for thoughts and suggestions at the end. The complete survey and results are
available in Appendix E, and questions are summarized below.
While all the benefits of trees are important to consider, the preferences of a community for
certain benefits can be used by tree managers to select appropriate trees to further meet the
needs of the community. When asked why trees are important to the City, shading/cooling,
community character/aesthetics, wildlife habitat, and improving air quality were most frequently
chosen. However, a majority of the benefits offered in the survey were rated as important,
including connection with nature, improving quality of life, and reducing urban heat island
effects.
Figure 7: San Luis Obispo Community Member Opinions on the Most Important Benefits of Trees
61.8%58.5%54.8%53.9%
46.6%46.4%42.6%
35.3%
16.8%15.7%14.4%13.4%
8.5%6.4%4.5%2.2%1.7%1.4%Shading/coolingCommunity character/aestheticsWildlife habitatImproving air qualityConnection with natureQuality of lifeReducing urban heat islandeffectsGreenhouse gas reductionReducing energy needsReducing stormwater runoffReducing stressEnhancing pedestrian/bikecorridorsScreening/creating privacyIncreasing property valuesReducing health incidence/costOther (please specify)Increasing retail salesSafety/reducing crime0
50
100
150
200
250
300
350
400
450
BenefitNumber of ResponsesPage 240 of 299
Benchmark Community Survey 88
The survey indicated that environmental benefits from trees are relatively equal in importance to the community. Respondents rated shading and cooling, greenhouse gas reduction, reducing urban heat island effects, and improving air quality each around 20%. The lowest rated benefits in level of importance were reducing stormwater runoff and wildlife habitat.
Figure 8: Community Member Opinions on the Most Important Environmental Benefit from Trees
Survey respondents were asked which socioeconomic benefits from trees they felt were most important and given 11 options to choose from. The most important benefits according to the
survey, in descending order, were community character/aesthetics, quality of life, connection to
nature, and reducing energy needs which together received 85.1% of the votes.
Figure 9: Community Member Opinions on the Most Important Socioeconomic Benefit from Trees
22.1%21.3%20.2%18.3%
13.4%
2.8%2.0%Greenhouse gasreductionShading/coolingReducing urbanheat island effectsImproving airqualityWildlife habitatReducingstormwater runoffOther (pleasespecify)0
20
40
60
80
100
120
140
160
Number of Responses32.8%
24.2%
16.6%
11.5%
3.6%3.1%2.3%2.0%1.7%1.1%0.6%0.5%Communitycharacter/aestheticsQuality of lifeConnection to natureReducing energy needsEnhancingpedestrian/bike corridorsReducing stressIncreasing propertyvaluesReducing healthincidence/costOther (please specify)Screening/creatingprivacyIncreasing retail salesSafety/reducing crime0
50
100
150
200
250
Number of ResponsesPage 241 of 299
89 Benchmark Community Survey
When asked where residents thought it was most important to plant trees, neighborhood streets, parks, and open space were most important, but respondents also mentioned trees should be planted everywhere. Respondents also emphasized the need for tree planting in medians along arterial roads, many of which lack greenery or canopy and feel like ‘freeways’ and to use these trees as traffic-calming devices. While locations such as schools, parking lots, and buffer zones between freeways and neighborhoods were not choices, respondents volunteered that these as important locations for further planting.
Figure 10: Community Member Opinions on Where it is Most Important to Plant More Trees
Private property planting is an important aspect of growing urban forest canopy and will be an
important factor in increasing canopy with San Luis Obispo. When asked what survey
respondents thought were the best ways to encourage private property planting, the top three
responses were to offer a free or low-cost tree, to offer a rebate on water bills, and to have a
rebate for purchased trees. Survey respondents also had other recommendations, such as
having a lawn sign or decal to show they are a part of the 10,000 Trees initiative, to hold a photo
contest, and to have a tax incentive.
Figure 11: Community Member Opinions on Encouraging Tree Planting on Private Property
77.3%
54.5%
40.9%34.7%29.3%28.9%
7.6%
Neighborhood
streets
Parks Open space Medians Retail areas Arterial roads Other (please
specify)
0
100
200
300
400
500
600
Number of Responses72.0%
61.2%
49.4%45.0%
34.7%
7.0%
Free or low-cost
tree
Rebate on water
bill
Rebate on
purchased tree
Tree species and
site selection
information
Community tree
planting event
Other (please
specify)
0
50
100
150
200
250
300
350
400
450
500
Number of ResponsesPage 242 of 299
Benchmark Community Survey 90
Overall, survey respondents were fairly aware of the urban forest program and its operations in the City. About 70% of respondents had seen city crews working on trees, and about 20% of respondents had used the City website or called about tree information. However, 25% of respondents were not aware that there was an urban forest program. Some of the respondents had connections with the Tree Committee, heard about the program through ECOSLO, had taken an Urban Forestry class at Cal Poly, or had personally planted trees at the Arbor Day events.
Figure 12: Community Member Awareness and Interactions with the Urban Forestry Program
Residents were generally satisfied with the level of care given to community trees. Most were
‘somewhat satisfied’ (38.4%) and neutral or no opinion (32.1%). A total of 16.8% of respondents
were either somewhat dissatisfied or completely dissatisfied with the level of tree care.
Figure 13: Community Member Opinions on the Level of Care Provided for Community Trees
Most respondents were not sure whether urban forest services and programs are equally accessible to all residents (63.3%). About 20% of respondents said that they are not equally accessible, whereas 16.5% answered that urban forest services are equally accessible.
70.3%
52.8%
25.4%20.4%15.6%
9.0%8.3%
I have seen City
crews working
on trees
I was aware
that the City
responds to
tree
emergencies
I did not know
the City had a
program to care
for trees
I have used the
City website or
called for tree
information
I have read an
article in The
New Times or
The San Luis
Obispo Tribune
about trees
Other (please
specify)
I have
volunteered at
tree related
events
0
50
100
150
200
250
300
350
400
450
Number of Responses38.4%
32.1%
12.8%11.1%
5.7%
Somewhat satisfied Neutral Completely satisfied Somewhat dissatisfied Completely
dissatisfied
0
50
100
150
200
250
Number of ResponsesPage 243 of 299
91 Benchmark Community Survey
Figure 14: Community Member Opinions on Whether Urban Forest Services and Programs are Equally
Accessible to all Residents
SLO survey respondents were interested in most topics of education and outreach presented in the survey. Most respondents were interested in information on a tree list and about which trees to plant in the City. They also indicated education and outreach regarding irrigation and watering during a drought as an important topic. Survey respondents also commented that
education could be provided in public schools and requested guidance and education regarding
tree planting for greenhouse gas reduction.
Figure 15: Community Member Opinions on Topics of Education and Outreach of Interest
63.3%
20.3%16.5%
Not sure No Yes
0
50
100
150
200
250
300
350
400
450
Number of Responses84.6%
73.9%
47.7%46.5%
28.4%
6.5%
Tree list/what tree
should I plant in
San Luis Obispo
Irrigation/watering
during drought
How to plant a
tree
Benefits of trees How to hire a tree
care professional
Other (please
specify)
0
100
200
300
400
500
600
Number of ResponsesPage 244 of 299
Benchmark Community Survey 92
Page 245 of 299
93 Analysis of Sustainability Indicators
Analysis of Sustainability Indicators
The Sustainability Indicators is a tool based on the Characteristics of Urban Forest Sustainability as defined in the 1997 Journal of Arboriculture article “A Model of Urban Forest Sustainability”, which describes specific criteria that can be used in conjunction with measurable indicators to evaluate sustainability (Clark et al. 1997). To identify goals and areas where the urban forestry program can be improved, Urban Forest Services can regularly assess, evaluate, and indicate the current performance levels of the urban forest through the Sustainability Indicators.
While the Sustainability Indicators is a useful tool for assessing the current status of an urban
forest program, it does not necessarily provide a comprehensive review of all the areas in which
a program could be improved. In the case of San Luis Obispo, not all of the indicator categories
are applicable to the Public Works Department. The Sustainability Indicators do provide an
opportunity for Urban Forest Services to benchmark their current conditions and understand
how they can be improved to meet industry recommendations and then establish performance
measures to improve the effectiveness of their management approach (Kenney, et al 2011). The
criteria for the Sustainability Indicators were used as a reference to assess the current urban
forestry practices in San Luis Obispo and proved the framework for describing what current
urban forest management looks like and a step to advance urban forest management. For a
detailed report of the results of the assessment, refer to Appendix D.
The Trees
Among the three performance areas, The Trees is where San Luis Obispo currently has the lowest performance. The categories relating to the tree inventory, such as Age of Trees and Condition of Publicly Owned Trees have low to medium ratings because most community trees are not receiving routine maintenance nor are their attributes regularly updated in an inventory system. Trees in the downtown core are the exception. Downtown trees are regularly maintained, they are also monitored for structural defects and trees are removed and replaced as needed. San Luis Obispo is moving toward proactive maintenance for trees along streets, in parks, rights-of-way, and at City facilities. As work is completed, inventory data specifications such as tree condition, defects, and any necessary maintenance tasks to address risk will be updated. As part of the next phase in the urban forest planning process, the City intends to update the entire tree
inventory, with the exception of trees located in open spaces.
Location of Canopy and Trees on Private Property were categories of low performance for San
Luis Obispo. These categories are used to assess whether a community has an equitable
distribution of canopy across the community and if the extent and health of canopy on private
property is well known. Currently, urban forest managers have access to limited, outdated
information on tree canopy in the built areas of the community. Furthermore, the community is
currently experiencing a considerable amount of infill development as a result of state housing
mandates. Like many California communities, development will continue to put pressure on
urban forest growth and result in additional competition for space for trees. Some development
plans omit setbacks, taking away already limited space for trees. As a result, the extent and
location of tree canopy is changing quickly. To progress in this area, the City should conduct a
land cover and tree canopy assessment to determine the amount and distribution of tree
Page 246 of 299
Analysis of Sustainability Indicators 94
canopy citywide and use this information to determine areas that are in the most need of additional tree preservation and planting efforts.
Table 2: Sustainable Indicators
Indicators of a Sustainable Urban Forest
Assessed
Performance Level
Low Medium High
The
Trees
Urban Tree Canopy
Equitable Distribution
Size/Age Distribution
Condition of Public Trees - Streets, Parks
Condition of Public Trees - Natural Areas n/a n/a n/a
Trees on Private Property
Species Diversity
Suitability
Soil Volume
The Players
Neighborhood Action
Large Private & Institutional Landholder
Involvement
Green Industry Involvement
City Department/Agency Cooperation
Funder Engagement
Utility Engagement
State Engagement
Public Awareness
Regional Collaboration
The
Management
Approach
Tree Inventory
Canopy Assessment
Management Plan
Risk Management Program
Maintenance of Publicly-Owned Trees (ROWs)
Maintenance of Publicly-Owned Natural Areas n/a n/a n/a
Planting Program
Tree Protection Policy
City Staffing and Equipment
Funding
Disaster Preparedness & Response
Communications
Totals 9.5 15.5 3.5
Page 247 of 299
95 Analysis of Sustainability Indicators
Although San Luis Obispo has not set canopy goals, community members initiated an aggressive tree planting initiative. While the majority of the trees planted as part of this initiative will occur in open spaces, it calls for a fully stocked inventory in built areas. Urban forest Services, in partnership with ECOSLO, is not on a trajectory to achieve a fully stocked inventory along streets, in parks, rights-of-way, and at City facilities by 2035. To meet this goal, Urban Forest Services will need to prioritize tree planting through the development and implementation of planting plans that not only outline planting sites and timeframes, but also
the roles of Urban Forest Services, ECOSLO, and contractors.
In The Trees indicator category, San Luis Obispo’s strongest areas of performance is in Species Diversity. As of 2008, the most abundant species, coast live oak (Quercus agrifolia), is native to the region and represents 10% of the entire population. All other species represent 5% or less of
the overall population. Incorporating as much species diversity into an urban population as
possible is hugely important for a sustainable and resilient urban forest, especially considering
current and emerging pests and disease threats. Although Urban Forest Services is likely still
meeting expectations in this area, striving for even greater diversity is well-advised.
The Players
The Players is a performance area where Urban Forest Services is consistently ranking in the medium category. Three categories were assessed as low to medium and could be improved to advance the urban forestry program, including large private and institutional landholder involvement, utility engagement, and funder engagement. Greater interaction with external groups could promote Urban Forest Service’s goals to provide proactive maintenance to all along streets, in parks, rights-of-way and at City facilities. Currently, all of the Urban Forest Service’s funding comes from the General Fund. While the community is currently supportive of urban forest goals, it is still important to secure adequate and sustainable funding.
Discussion with Urban Forest Services and other urban forest partners revealed that communication between teams is generally good. Collaborations are often on a project-specific basis and most frequently revolve around emergency response. While communication avenues are in place, the current workload hinders Urban Forest Service’s ability to be a stronger
collaborator toward shared visions for the urban forest. One area in particular, development
review, has fallen by the wayside due to the recent increase in development and the lack of a
review arborist. Development proposals often result in the loss of mature trees which is a
primary concern of community members that feel the City is not doing enough to preserve the
urban forest.
As a whole, the community has a great appreciation for trees and a strong desire to support tree
canopy through the preservation of existing trees and increased planting efforts. In fact, the
community was integral to the robust tree planting initiative outlined in the Climate Action Plan
and recognizes the urban forest for its role in providing a number of benefits to health and
welfare of the community. Urban Forest Services relies on their nonprofit partner, ECOSLO, to
coordinate with volunteers for tree planting and care in urban areas. While coordinated
neighborhood action is limited to the Downtown Foresters and Downtown Ambassadors, many
residents volunteer to support the urban forest.
Page 248 of 299
Analysis of Sustainability Indicators 96
The Management Approach
Finally, The Management Approach is the area identified by the assessment to have the most criteria where the urban forestry program is performing at medium to high levels. The
community’s tree protection policy is an area of high performance for the program, as the policy
not only protects benefits derived from trees on public property, but also those on private
property. While this is a significant achievement for the program, this area can further be
strengthened through educational campaigns to increase community awareness for the
ordinance and expanded enforcement to protect the resource and the benefits derived from all
trees.
Recent retirements and general staff attrition have strained staffing levels and at the current
level (two staff) is inadequate to effectively manage the resource and the urban forestry
program. As a result, the program is performing at a medium level in the City Staffing and
Equipment categories. This area has numerous opportunities for improvement, as the intention
is to increase staffing levels and expand the use of contractors to provide regular and routine maintenance for all community trees. Improvements in these two categories could also result in improvements in other areas, such as Risk Management, which was ranked low. To enhance performance in this category, Urban Forest Services should conduct annual inspections and proactively address hazards.
Tree Inventory and Canopy Assessment are areas of medium performance. Currently, the program does not have a comprehensive and complete GIS-based community tree inventory nor an urban forest canopy assessment based on high-resolution tree canopy imagery. Updates to the inventory, will provide greater knowledge about the community tree resource. Further study and assessment of overall canopy cover could assist in community-wide planting projects, like the 10,000 Trees initiative. Both an inventory and a canopy assessment would aid in the development of management plan, which would define long-term maintenance schedules, planting plans that consider the strategic placement of trees to maximize benefits. The implementation of a management plan would further advance the program in the Management Plan category. These would give the urban forest program a greater understanding of the
current resource, benchmark canopy levels, and help determine progress on their planting
initiatives.
“Progressive cities like ours should lead the way in tempering our desire to
provide additional housing with the restraint necessary to keep from destroying
the very reason we love our community.”
-Survey Respondent
Page 249 of 299
97 Conclusion
Conclusion
The information gathered during this review of the urban forestry program provided an initial assessment of the challenges and opportunities for San Luis Obispo’s urban forest. Further exploration of urban forestry partnerships, community engagement, and assessment of the community tree resource and overall canopy will be critical for the development of a comprehensive urban forest strategic plan. The initial review of tree care operations, staffing, policies and guiding documents, and community feedback have emphasized a critical need for improvements in the care for the community tree resource.
Challenges with staffing have resulted in long-term delays of routine care for trees in most areas
of the community, which prior to 2019, were receiving care every 8 to 10 years. With the
implementation of contractor services to provide routine care in 2021, Urban Forest Services is
moving toward a cyclical maintenance cycle for the estimated 20,000 trees along streets, in
parks, public rights-of-way, and at City facilities. Tree maintenance in the downtown core is a
priority and these trees receive regular care, but all other maintenance is reactionary, driven by
responding to service requests, work orders, or concerns. Ideally, Urban Forest Services would
have all trees on a predictable pruning schedule, considering species that require more frequent
maintenance (such as palms and Ficus spp.). Many of the concerns around establishing more
proactive maintenance can be addressed by (1) contracting out cycle pruning, (2) reinstating an
in-house crew to address service requests and work orders, and (3) developing comprehensive
schedules and work plans that consider routine maintenance needs, rotation schedules, and the
time required to complete necessary maintenance (e.g., average time to complete maintenance).
Urban forest partners are critical to meeting the long-term goals for the urban forest. While Urban Forest Services is responsible for the maintenance of trees in the built areas of the community, staff in the Parks and Recreation Department and Administration Department care for a large portion of the urban forest and provide critical visioning and goals setting. The City’s partnership with ECOSLO has been integral to tree planting and establishment. Over the past 2 years, approximately half of the tree plantings in the urban areas of San Luis Obispo have been planted by volunteers through this program each year. Departments collaborate to effectively address storm response. Through open communication and shared equipment, these situations can be quickly addressed.
Prior to 2008, it was standard procedure that the inventory was updated as work was completed. At the time, the species diversity, age distribution, and condition ratings indicated a diverse, ideally aged resource in fair or better condition. Since that time, the inventory has not stayed current and therefore the current structure and health of the community tree resource is largely unknown. An up-to-date, regularly maintained inventory is key to understanding the tree
resource in real time, which is especially helpful for assisting staff in determining and prioritizing
tree care and tree planting. Urban Forest Services recognizes the importance of having a current
inventory and there are efforts underway to update the inventory by completing a
comprehensive inventory. The updated data specifications for the community tree resource will
provide the necessary information to develop a plan for maintenance and identify areas where
tree planting is needed to replace trees that have previously been removed or to plan for the
succession of an aging and maturing trees, especially in the downtown core.
Page 250 of 299
Conclusion 98
Responses to an online community survey revealed that trees are greatly appreciated by residents and are seen as a valuable part of the community’s identity. Respondents noted that trees are most appreciated for providing shade and contributing positively to the overall community aesthetics. Through comments, respondents voluntarily expressed great concern over the loss of mature trees as a result of the recent increase in development.
A strength of San Luis Obispo’s urban forestry program is that there is a strong tree protection ordinance. The ordinance not only prohibits the removal and pruning of public trees, but also trees on private property. Furthermore, if trees are removed, those trees must be replaced with a sufficient number of trees as determined by the ordinance, Tree Committee, or City Arborist. While mitigation planting can help offset some of the benefits that are lost from mature trees that are removed, sufficiently replacing mature trees with mitigation plantings takes decades, as
trees planted as part of mitigation efforts will take a long time to achieve the same level of
canopy as the trees that were removed. Although mitigations are required per Municipal Code,
not all large statured trees are being replaced with species of similar stature. As San Luis Obispo
continues to undergo infill development and potentially expand, undoubtedly trees will continue
to be affected. Feedback from stakeholders and the community suggest that expanded
education to the community about the tree protection ordinance, coupled with expanded
development review, and clarification of the role of the Tree Committee will be critical to
protecting large, mature trees and preserving tree canopy.
From this assessment of the urban forestry program, it is clear that further study and examination of urban forest partnerships and community engagement are needed to not only improve the urban forestry program, but also to develop a comprehensive urban forest strategic plan, which will ensure that the necessary resources are in place to care for the entire community tree resource and provide a long-term vision for the urban forest. In order to develop a comprehensive urban forest strategic plan future planning phases should include:
• A comprehensive tree inventory that is regularly updated by all urban forest partners
• A Resource Analysis that benchmarks the composition, benefits, and the value of
the community tree resource
• Mapping of the existing canopy and summarize results through a Canopy and Land Cover Assessment
• Management plans and budget needs to maintain trees on a 6-year cycle
• Further engagement of applicable stakeholders to identify and build consensus for solutions to challenges and opportunities that were identified for trees managed by Urban Forest Services in the summary report
• Consideration for challenges and opportunities for the remainder of the urban forest, including trees maintained by other departments in open space, natural areas, and riparian areas, private landowners, and other government agencies
• Robust community engagement
Additional discussions with urban forest partners and the community will be required to determine the path forward to re-enacting the high-performing urban forestry program with
Page 251 of 299
99 Conclusion
restoring service to the level prior to 2019. Discussions with Public Works and urban forest partners coupled with a review of policies and guiding documents have revealed great concern over the need to provide a greater level of care to San Luis Obispo’s community trees. With adequate staffing levels and continued contracted maintenance, San Luis Obispo’s urban forestry program will be on the right track to re-enact a high-performing urban forestry program, considering:
• Secured funding for increased staffing and contract maintenance
• Ambitious tree planting initiatives
• Collaborative avenues in place amongst Departments
• Engaged, passionate, and supportive community members
• Progress in increasing the level of performance in meeting Sustainability Indicators
Page 252 of 299
Conclusion 100
Page 253 of 299
101 Appendix A: References
Appendix A: References
Bastin J-F, Clark E, Elliott T, Hart S, van den Hoogen J, Hordijk I, et al. (2019) Understanding climate change from a global analysis of city analogues. PLoS ONE 14(7): e0217592. https://doi.org/10.1371/journal.pone.0217592
Bond, J. and Buchanan, A. 2006. Best Management Practices Tree Inventories. International Society of Arboriculture. Champaign, IL.
California Legislative Information. 2021. Senate Bill #9. Chapter 162 of Government Code Regarding Land Use. Retrieved from: https://leginfo.legislature.ca.gov/faces/billNavClient.xhtml?bill_id=202120220SB9
California Oak Mortality Task Force. 2020. Maps & Visual Media. Retrieved from: http://www.suddenoakdeath.org/
California Office of Environmental Health Hazard Assessment. 2021. Traffic density. Retrieved from: https://oehha.ca.gov/calenviroscreen/indicator/traffic-density
City of San Luis Obispo. 2021. Fire Department: About Us. Retrieved from: https://www.slocity.org/government/department-directory/fire-department/about-us
Cal Poly. 2020. Cal Poly Honored Again by Arbor Day Foundation as a Tree Campus USA. Retrieved from: https://calpolynews.calpoly.edu/news_releases/2020/april/arbor_day
Carter, J. G., Cavan, G., Connelly, A., Guy, S., Handley, J., & Kazmierczak, A. (2015). Climate change and the city: Building capacity for urban adaptation. Progress in Planning, 95, 1-66.
Clark et al. 1997. A Model of Urban Forest Sustainability. Journal of Arboriculture 23(1). Retrieved
from: https://naturewithin.info/Policy/ClarkSstnabltyModel.pdf
City of San Luis Obispo. N.d. Sustainable Growth Management. Retrieved from: https://www.slocity.org/home/showpublisheddocument/21740/636734813174500000
City of San Luis Obispo Fire Department. 2021. About us. Retrieved from: https://www.slocity.org/government/department-directory/fire-department/about-us
Clark, J.R., Matheny, N.P., Cross, G., Wake, V. 1997. A Model of Urban Forest Sustainability. J Arbor 23(1):17-30.
Daugherty, M. and Hung, K. n.d. Sudden Oak Death. University of California Riverside Center for Invasive Species Research. https://cisr.ucr.edu/invasive-species/sudden-oak-death
Day, S. D., Wiseman, P. E., Dickinson, S. B., & Harris, J. R. (2010). Contemporary concepts of root system architecture of urban trees. Arboriculture & Urban Forestry, 36(4), 149-159.
Downtown SLO. 2021. Downtown San Luis Obispo. Retrieved from: https://downtownslo.com/
Page 254 of 299
Appendix A: References 102
EDDMapS. 2021. Early Detection & Distribution Mapping System. The University of Georgia —Center for Invasive Species and Ecosystem Health. Retrieved from http://www.eddmaps.org/
Eskalen, A. Kabashima, J., and Dimson, M. 2017. Invasive Shot Hole Borer and Fusarium Dieback Field Guide. Identifying signs and symptoms of the Polyphagous and Kuroshio Shot Hole Borer. University of California, Agriculture and Natural Resources. Retrieved from: https://ucanr.edu/sites/eskalenlab/files/290780.pdf
Grafton-Cardwel, Daugherty, Jetter, & Johnson. 2019. ACP/HLB Distribution and Management.
University of California, Division of Agriculture and Natural Resources. Retrieved from:
https://ucanr.edu/sites/ACP/
Janowiak, Maria K.; Brandt, Leslie A.; Wolf, Kathleen L.; Brady, Mattison; Darling, Lindsay; Lewis, Abigail Derby; Fahey, Robert T.; Giesting, Kristen; Hall, Eboni; Henry, Molly; Hughes, Maise;
Miesbauer, Jason W.; Marcinkowski, Kailey; Ontl, Todd; Rutledge, Annamarie; Scott, Lydia;
Swanston, Christopher W. 2021. Climate adaptation actions for urban forests and human health.
Gen. Tech. Rep. NRS-203. Madison, WI: U.S. Department of Agriculture, Forest Service, Northern
Research Station. 115 p. https://doi.org/10.2737/NRS-GTR-203
Johnson, P. 2021. Building out: The city of SLO has enough housing under construction to reach its growth cap ahead of schedule. New Times SLO. Retrieved from:
https://www.newtimesslo.com/sanluisobispo/building-out-the-city-of-slo-has-enough-housing-under-construction-to-reach-its-growth-cap-ahead-of-schedule/Content?oid=10949205
Kenney, W. A., van Wassenaer, P. J., & Satel, A. L. 2011. Criteria and indicators for strategic urban forest planning and management. Arboriculture & Urban Forestry, 37(3), 108-117.
Management and Performance Audit of the Public Works Department. 2011.
Nessen, K. 2012. Estimating urban canopy cover in San Luis Obispo. PDF power point presentation.
Richards, N.A. 1982/83. Diversity and Stability in a Street Tree Population. Urban Ecology. 7:159-171.
Santamour, F. 1990. Trees for urban planting: Diversity, uniformity, and common sense. Proceedings of the 7th Conference of Metropolitan Tree Improvement Alliance. 7.
Senate Bills 8. Housing Crisis Act of 2019. https://leginfo.legislature.ca.gov/faces/billNavClient.xhtml?bill_id=202120220SB8
Senate Bill 9. Housing development: approvals. https://leginfo.legislature.ca.gov/faces/billNavClient.xhtml?bill_id=202120220SB9
Senate Bill 10. Planning and zoning: housing development: density. https://leginfo.legislature.ca.gov/faces/billNavClient.xhtml?bill_id=202120220SB10
Page 255 of 299
103 Appendix A: References
SLO City. n.d. Sustainable Growth Management. Retrieved from https://www.slocity.org/home/showpublisheddocument/21740/636734813174500000
Umeda, C., Eskalen, A., and Paine, T. D. 2016. Polyphagous shot hole borer and Fusarium dieback in California. Insects and Diseases of Mediterranean Forest Systems (pp. 757-767). Springer, Cham.
University of California. 2021. Pest Overview: Invasive Shot Hole Borers. Retrieved from: https://ucanr.edu/sites/pshb/pest-overview/#about-the-beetles
Wiley, Hannah. 2021. “More duplexes. Gavin Newsom signs bills aimed at creating more
affordable housing in California.” Retrieved from: https://www.sacbee.com/news/politics-government/capitol-alert/article254302493.html
Wiseman, P. E., & Raupp, R. J. 2016. Best Management Practices. Integrated Pest Management, 2nd ed. International Society of Arboriculture, Champaign, IL.
Zhu, K., Woodall, C. W., & Clark, J.S. 2012. Failure to migrate: lack of tree range expansion in response to climate change. Global Change Biology, 18(3), 1042-1052.
Page 256 of 299
Appendix B: Industry Standards 104
Appendix B: Industry Standards
ANSI Z133 Safety Standard, 2017
Reviews general safety, electrical hazards, use of vehicles and mobile equipment, portable power hand tools, hand tools and ladders, climbing, and work procedures.
ANSI A300
ANSI A300 standards represent the industry consensus on performing tree care operations. The standards can be used to prepare tree care contract specifications.
ANSI A300 Pruning Standard-Part 1, 2017
ANSI A300 Soil Management-Part 2, 2011
ANSI A300 Support Systems Standard-Part 3, 2013
ANSI A300 Construction Management Standard-Part 5, 2012
ANSI A300 Transplanting Standard-Part 6, 2012
ANSI A300 Integrated Vegetation Management Standard-Part 7,2012
ANSI A300 Root Management Standard-Part 8, 2013
ANSI A300 Tree Risk Assessment Standard a Tree Failure-Part 9, 2017
ANSI A300 Integrated Pest Management-Part 10, 2016
Includes guidelines for implementing IPM programs, including standards for Integrated Pest Management, IPM Practices, tools and equipment, and definition.
Best Management Practices (BMPs)
Integrated Pest Management, Second Edition, P. Eric Wiseman and Michael J. Raupp, 2016
Provides a comprehensive overview of the basic definitions, concepts, and practices that pertain
to landscape Integrated Pest Management (IPM). The publication provides specific information
for designing, planning, and implementing an IPM program as part of a comprehensive Plant
Health Care (PHC) management system, including topics such as:
• IPM Concepts and Definitions
• Action Thresholds
• Monitoring Tools and Techniques
• Preventive Tactics
• Control Tactics
• Documentation and Recordkeeping
Integrated Vegetation Management, Second Edition, Randall H. Miller, 2014
A guide to the selection and application of methods and techniques for vegetation control for
electric rights-of-way projects and gas pipeline rights-of-way. Topics included: safety, site
evaluations, action thresholds, evaluation, and selection of control methods, implementing
Page 257 of 299
105 Appendix B: Industry Standards
control methods, monitoring treatment and quality assurance, environmental protection, tree pruning and removal, and a glossary of terms.
Managing Trees During Construction, Second Edition, Kelby Fite and E. Thomas Smiley, 2016
Describes tree conservation and preservation practices that help to protect selected trees throughout the construction planning and development process so that they will continue to provide benefits for decades after site disturbance, including planning phase, design phase, pre-construction phase, construction phase, and post-construction phase.
Root Management, Larry Costello, Gary Watson, and Tom Smiley, 2017
Recommended practices for inspecting, pruning, and directing the roots of trees in urban environments to promote their longevity, while minimizing infrastructure conflicts.
Special companion publication to the ANSI A300 Part 8: Tree, Shrub, and Other Woody Plant Management–Standard Practices (Root Management)
Tree Planting, Second Edition, Gary Watson, 2014
Provides processes for tree planting, including site and species selection, planting practices, post-planting pruning, and early tree care. Other topics included are time of planting, nursery stock: types, selection, and handling, preparing the planting hole, planting practices, root loss and new root growth, redevelopment of root structure, pruning, palms, after planting, final inspection, and a glossary of terms.
Tree Inventories, Second Edition, Jerry Bond, 2013
Provides considerations for managing large numbers of trees considered as individuals rather than groups and serves as a guide for making informed decisions that align with inventory goals with needs and resources, including inventory goals and objectives, benefits and costs, types, work specifications, and maintaining inventory quality.
Tree Risk Assessment, Second Edition, E. Thomas Smiley, Nelda Matheny, and Sharon Lilly, 2017
A guide for assessing tree risk as accurately and consistently as possible, to evaluate that risk, and to recommend measures that achieve an acceptable level of risk, including topics: risk assessment basics, levels and scope of tree risk assessment, assessing targets, sites, and trees, tree risk categorization, risk mitigation: preventive and remedial actions, risk reporting, tree related conflicts that can be a source of risk, loads on trees, structural defects and conditions that affect likelihood of failure, response growth, description of selected types of advanced tree risk assessments.
Tree Shrub Fertilization, Third Edition, E. Thomas Smiley, Sharon Lilly, and Patrick Kelsey, 2013
Aides in the selection and application of fertilizers for trees and shrubs, including: Essential elements, determining goals and objectives of fertilization, soil testing and plan analysis, fertilizer selection, timing, application, application area, rates, storage and handling of fertilizer, sample fertilizer contract for commercial/ municipal clients.
Page 258 of 299
Appendix B: Industry Standards 106
Soil Management, Bryant Scharenbroch, E. Thomas Smiley, and Wes Kocher, 2014
Focuses on the protection and restoration of soil quality that support trees and shrubs in the urban environment, including goals of soil management, assessment, sampling, and analysis, modifications and amendments, tillage, conservation, and a glossary of terms.
Utility Pruning of Trees, Geoffrey P. Kempter, 2004
Describes the current best practices in utility tree pruning based on scientific research and proven methodology for the safe and reliable delivery of utility services, while preventing unnecessary injury to trees. An overview of safety, tools, and equipment, pruning methods and practices, and emergency restoration are included.
Page 259 of 299
107 Appendix C: Estimated Time on Services
Appendix C: Estimated Time on Services
Table 3: Tasks and Estimated Time Spent by Urban Forest Services Staff
Urban Forest Services Task Hours Allocated Each Week
Asset Management and Maintenance
Pruning in ROW, Parks, and City Facilities 60-90
Commemorative Grove planting and maintenance 5
Commemorative Grove mowing and watering 15a
Young tree care and watering 40
Emergency response 10-15
Citizen complaint and correspondences 10
Inventory management, including private heritage trees 5-10
Removal applications 5-15
Tree planting in empty wells 1-2b
Pest management 20d
Coordination for hardscape repairs/CIP Projects 1-3
Contract monitoring 5-20
Iron grate services 0-5
Code Enforcement
Illegal removal enforcement 2-5
Vegetation in the ROW enforcement 1-2
Inspect tree planting 0-2
Mitigation planting enforcement 0-2
Regulatory Framework
Development review 2-6
Development inspections 2-4
Regulatory framework for public and private trees 0-2
Education and Outreach
Education and outreach 0-10c
Arbor Day celebration 50-60d,e
Advisory Roles
Tree Committee liaison 3-5
Other
Clearance and visibility on private trees 0-1
aDuring summer and/or drought
bCity staff time (does not include contractor time)
cSporadic; can vary
dAnnual hours
e3-4 staff a whole month to prepare
Page 260 of 299
Appendix D: Sustainability Indicators 108
Appendix D: Sustainability Indicators
Table 4: The Trees
THE TREES
Indicators of a
Sustainable Urban
Forest
Overall Objective or
Industry Standard
Performance Levels
Low Medium High
Urban Tree Canopy
Achieve the desired tree
canopy cover according
to goals set for the entire
city and neighborhoods.
Alternatively, achieve
75% of the total canopy
possible for the entire
city and in each
neighborhood.
Canopy is
decreasing.
- and/or -
No canopy goals
have been set.
Canopy is not
dropping, but not on
a trajectory to
achieve the
established goal.
Canopy goal is
achieved, or well on
the way to
achievement.
Canopy goals have not been set, but the community has an
aggressive tree planting initiative.
Location of Canopy
(Equitable Distribution)
Achieve low variation
between tree canopy and
equity factors citywide by
neighborhood. Ensure
that the benefits of tree
canopy are available to
all, especially for those
most affected by these
benefits.
Tree planting and
public outreach
and education is
not determined by
tree canopy cover
or benefits.
Tree planting and
public outreach and
education is focused
on neighborhoods
with low tree
canopy.
Tree planting and
public outreach and
education is focused
on neighborhoods
with low tree
canopy and a high
need for tree
benefits.
Tree plantings are ongoing through a partnership with ECOSLO.
Age of Trees (Size and
Age Distribution)
Establish a diverse-aged
population of public trees
across the entire city and
for each neighborhood.
Ideal standard:
0-8" DBH: 40%
9-17" DBH: 30%
18-24" DBH: 20%
Over 24" DBH: 10%
No current
information is
available on size.
- OR -
Age distribution is
not proportionally
distributed across
size classes at the
City level.
Size classes are
evenly distributed at
the City level,
though unevenly
distributed at the
neighborhood level.
Age distribution is
generally aligned
with the ideal
standard diameter
classes at the
neighborhood level.
Current information on age distribution is not available, but the
outdated inventory data (2008) shows a nearly ideal distribution.
Page 261 of 299
109 Appendix D: Sustainability Indicators
Condition of Publicly
Owned Trees (trees
managed intensively)
Possess a detailed
understanding of tree
condition and potential
risk of all intensively-
managed, publicly-owned
trees. This information is
used to direct
maintenance actions.
No current
information is
available on tree
condition or risk.
Information from a
partial or sample or
inventory is used to
assess tree condition
and risk.
Information from a
current, GIS-based,
100% complete
public tree inventory
is used to indicate
tree condition and
risk.
A partial inventory is regularly monitored, it includes street trees in
the Downtown core.
Condition of Publicly-
Owned Natural Areas
(trees managed
extensively)
Possess a detailed
understanding of the
ecological structure and
function of all publicly-
owned natural areas
(such as woodlands,
ravines, stream corridors,
etc.), as well as usage
patterns.
No current
information is
available on tree
condition or risk.
Publicly-owned
natural areas are
identified in a
sample-based
"natural areas
survey" or similar
data.
Information from a
current, GIS-based,
100% complete
natural areas survey
is utilized to
document ecological
structure and
function, as well as
usage patterns.
n/a
Trees on Private
Property
Possess a solid
understanding of the
extent, location, and
general condition of trees
on private lands.
No data is available
on private trees.
Current tree canopy
assessment reflects
basic information
(location) of both
public and private
canopy combined.
Detailed information
available on private
trees. Ex. bottom-up
sample-based
assessment of trees.
The location and health of the canopy on private property is largely
unknown.
Diversity
Establish a genetically
diverse population of
publicly-owned trees
across the entire city and
for each neighborhood.
Tree populations should
be comprised of no more
than 30% of any family,
20% of any genus, or 10%
of any species.
No current
information is
available on
species.
- OR -
Fewer than five
species dominate
the entire tree
population
citywide.
No species
represents more
than 20% of the
entire tree
population citywide.
No species
represents more
than 10% of the
entire tree
population citywide.
The most abundant species represents 10% of the population. All
other species are less than 5% of the population.
Page 262 of 299
Appendix D: Sustainability Indicators 110
Climate
Resilience/Suitability
Establish a tree
population suited to the
urban environment and
adapted to the overall
region. Suitable species
are gauged by exposure
to imminent threats,
considering the "Right
Tree for the Right Place"
concept and invasive
species.
No current
information is
available on species
suitability.
- OR -
Less than 50% of
trees are
considered suitable
for the site.
50% to 75% of trees
are considered
suitable for the site.
More than 75% of
trees are considered
suitable for the site.
An approved street tree list is available but does not include
consideration for characteristics to help determine appropriate
planting spaces.
Space and Soil Volume
Establish minimum street
tree soil volume
requirements to ensure
there is adequate space
and soil for street trees to
thrive. Minimum soil
volumes by mature size:
1000 cubic feet for large
trees; 600 cubic feet for
medium trees; 300 cubic
feet for small trees.
Minimum street
tree soil volumes
have not been
established.
Minimum street tree
soil volume has been
established based
on mature size of
tree.
Minimum street tree
soil volumes have
been established
and are required to
be adhered to for all
new street tree
planting projects.
No soil volumes have been established; however, tree well size
dictates tree species.
Page 263 of 299
111 Appendix D: Sustainability Indicators
Table 5: The Players
THE PLAYERS
Indicators of a
Sustainable Urban
Forest
Overall Objective or
Industry Standard
Performance Levels
Low Medium High
Neighborhood Action
Citizens understand,
cooperate, and
participate in urban
forest management at
the neighborhood level.
Urban forestry is a
neighborhood-scale
issue.
Little or no citizen
involvement or
neighborhood
action.
Some active groups
are engaged in
advancing urban
forestry activity, but
with no unified set
of goals or
priorities.
The majority of all
neighborhoods are
organized,
connected, and
working towards a
unified set of goals
and priorities.
The City has the Downtown Foresters who assist with pruning and
care for small trees in the downtown core.
Large Private &
Institutional Landholder
Involvement
Large, private, and
institutional landholders
embrace citywide goals
and objectives through
targeted resource
management plans.
Large private land
holders are
unaware of issues
and potential
influence in the
urban forest. No
large private land
management plans
are currently in
place.
Education materials
and advice is
available to large
private landholders.
Few large private
landholders or
institutions have
management plans
in place.
Clear and concise
goals are established
for large private land
holders through
direct education and
assistance programs.
Key landholders and
institutions have
management plans in
place.
Green Industry
Involvement
The green industry works
together to advance
citywide urban forest
goals and objectives. The
city and its partners
capitalize on local green
industry expertise and
innovation.
Little or no
involvement from
green industry
leaders to advance
local urban forestry
goals.
Some partnerships
are in place to
advance local urban
forestry goals, but
more often for the
short-term.
Long-term
committed
partnerships are
working to advance
local urban forestry
goals.
Some partnerships are in place (e.g., ECOSLO, and Cal Poly).
Page 264 of 299
Appendix D: Sustainability Indicators 112
City Department and
Agency Cooperation
All city departments and
agencies cooperate to
advance citywide urban
forestry goals and
objectives.
Conflicting goals
and/or actions
among city
departments and
agencies.
Informal teams
among departments
and agencies are
communicating and
implementing
common goals on a
project-specific
basis.
Common goals and
collaboration occur
across all
departments and
agencies. City policy
and actions are
implemented by
formal
interdepartmental
and interagency
working teams on all
city projects.
The different Departments work well together, but the current work
load prevents the optimal level of collaboration.
Funder Engagement
Local funders are
engaged and invested in
urban forestry initiatives.
Funding is adequate to
implement citywide
urban forest
management plan.
Little or no funders
are engaged in
urban forestry
initiatives.
Funders are
engaged in urban
forestry initiatives
at minimal levels for
short-term projects.
Multiple funders are
fully engaged and
active in urban
forestry initiatives for
short-term projects
and long-term goals.
Limited funding comes from local partnerships.
Utility Engagement
All utilities are aware of
and vested in the urban
forest and cooperates to
advance citywide urban
forest goals and
objectives.
Utilities and city
agencies act
independently of
urban forestry
efforts. No
coordination exists.
Utilities and city
agencies have
engaged in
dialogues about
urban forestry
efforts with respect
to capital
improvement and
infrastructure
projects.
Utilities, city
agencies, and other
stakeholders
integrate and
collaborate on all
urban forestry
efforts, including
planning, site work,
and
outreach/education.
Some coordination exists.
State Engagement
State
departments/agencies
are aware of and vested
in the urban forest and
cooperates to advance
citywide urban forest
goals and objectives.
State
departments/agenci
es and City agencies
act independently
of urban forestry
efforts. No
coordination exists.
State department/
agencies and City
agencies have
engaged in
dialogues about
urban forestry
efforts with respect
to capital
improvement and
infrastructure
projects.
State
departments/agencie
s, City agencies, and
other stakeholders
integrate and
collaborate on all
urban forestry
efforts, including
planning, site work,
and
outreach/education.
Page 265 of 299
113 Appendix D: Sustainability Indicators
Public Awareness
The general public
understands the benefits
of trees and advocates
for the role and
importance of the urban
forest.
Trees are generally
seen as a nuisance,
and thus, a drain on
city budgets and
personal paychecks.
Trees are generally
recognized as
important and
beneficial.
Trees are seen as
valuable
infrastructure and
vital to the
community’s well-
being. The urban
forest is recognized
for the unique
environmental,
economic, and social
services it provides to
the community.
The community is very support of the Major City Goal on Climate
Change/Sustainability and know the importance trees play in this.
Regional Collaboration
Neighboring
communities and
regional groups are
actively cooperating and
interacting to advance
the region's stake in the
City's urban forest.
Little or no
interaction between
neighboring
communities and
regional groups.
Neighboring
communities and
regional groups
share similar goals
and policy vehicles
related to trees and
the urban forest.
Regional urban
forestry planning,
coordination, and
management is
widespread.
Some regional collaboration exists (e.g., participation in regional
pest and disease programs).
Page 266 of 299
Appendix D: Sustainability Indicators 114
Table 6: The Management Approach
THE MANAGEMENT APPROACH
Indicators of a
Sustainable Urban
Forest Overall Objective or
Industry Standard
Performance Levels
Low Medium High
Tree Inventory
Comprehensive, GIS-
based, current inventory
of all intensively-
managed public trees to
guide management, with
mechanisms in place to
keep data current and
available for use. Data
allows for analysis of age
distribution, condition,
risk, diversity, and
suitability.
No inventory or
out-of-date
inventory of
publicly-owned
trees.
Partial or sample-
based inventory of
publicly-owned
trees, inconsistently
updated.
Complete, GIS-based
inventory of publicly-
owned trees,
updated on a regular,
systematic basis.
The inventory is outdated (2008) and not updated regularly when
maintenance occurs. Funds are in place to complete an inventory.
Canopy Assessment
Accurate, high-
resolution, and recent
assessment of existing
and potential city-wide
tree canopy cover that is
regularly updated and
available for use across
various departments,
agencies, and/or
disciplines.
No tree canopy
assessment.
Sample-based
canopy cover
assessment or
dated (over 10
years old) high
resolution canopy
assessment.
High-resolution tree
canopy assessment
using aerial
photographs or
satellite imagery.
Aerial imagery was analyzed to understand canopy cover in the
urban areas (2012).
Management Plan
Existence and buy-in of a
comprehensive urban
forest management plan
to achieve city-wide
goals. Re-evaluation is
conducted every 5 to 10
years.
No urban forest
management plan
exists.
A plan for the
publicly-owned
forest resource
exists but is limited
in scope,
acceptance, and
implementation.
A comprehensive
plan for the publicly
owned forest
resource exists and is
accepted and
implemented.
There is not an urban forest master plan, but funds are in place to
compete a plan.
Risk Management
Program
All publicly-owned trees
are managed for
maximum public safety
by way of maintaining a
city-wide inventory,
conducting proactive
annual inspections, and
eliminating hazards
within a set timeframe
based on risk level. Risk
management program is
Request-based,
reactive system.
The condition of
publicly-owned
trees is unknown.
There is some
degree of risk
abatement thanks
to knowledge of
condition of
publicly-owned
trees, though
generally still
managed as a
request-based
reactive system.
There is a complete
tree inventory with
risk assessment data
and a risk abatement
program in effect.
Hazards are
eliminated within a
set time period
depending on the
level of risk.
Page 267 of 299
115 Appendix D: Sustainability Indicators
outlined in the
management plan. There is not a risk assessment program.
Maintenance Program
of Publicly-Owned Trees
(trees managed
intensively)
All intensively-managed,
publicly-owned trees are
well maintained for
optimal health and
condition in order to
extend longevity and
maximize benefits. A
reasonable cyclical
pruning program is in
place, generally targeting
5 to 7-year cycles. The
maintenance program is
outlined in the
management plan.
Request-based,
reactive system. No
systematic pruning
program is in place
for publicly-owned
trees.
All publicly-owned
trees are
systematically
maintained, but
pruning cycle is
inadequate.
All publicly-owned
trees are proactively
and systematically
maintained and
adequately pruned
on a cyclical basis.
Trees in the Downtown core are well maintained, all other
maintenance is reactionary.
Maintenance Program
of Publicly-Owned
Natural Areas
(trees managed
extensively)
The ecological structure
and function of all
publicly-owned natural
areas are protected and
enhanced while
accommodating public
use where appropriate.
No natural areas
management plans
are in effect.
Only reactive
management
efforts to facilitate
public use (risk
abatement).
Management plans
are in place for each
publicly-owned
natural area focused
on managing
ecological structure
and function and
facilitating public
use.
n/a
Planting Program
Comprehensive and
effective tree planting
and establishment
program is driven by
canopy cover goals,
equity considerations,
and other priorities
according to the plan.
Tree planting and
establishment is outlined
in the management plan.
Tree establishment
is ad hoc.
Tree establishment
is consistently
funded and occurs
on an annual basis.
Tree establishment is
directed by needs
derived from a tree
inventory and other
community plans and
is sufficient in
meeting canopy
cover objectives.
Although Urban Forest Services does not have a planting program,
staff partner with ECOSLO for tree planting.
Page 268 of 299
Appendix D: Sustainability Indicators 116
Tree Protection Policy
Comprehensive and
regularly updated tree
protection ordinance
with enforcement ability
is based on community
goals. The benefits
derived from trees on
public and private
property are ensured by
the enforcement of
existing policies.
No tree protection
policy.
Policies are in place
to protect trees, but
the policies are not
well-enforced or
ineffective.
Protections policies
ensure the safety of
trees on public and
private land. The
policies are enforced
and supported by
significant deterrents
and shared
ownership of city
goals.
Municipal Code Chapter 12.24 provides protections for the majority
of trees (public and private).
City Staffing and
Equipment
Adequate staff and
access to the equipment
and vehicles to
implement the
management plan. A
high-level urban forester
or planning professional,
strong operations staff,
and solid certified
arborist technicians.
Insufficient staffing
levels, insufficiently-
trained staff, and/or
inadequate
equipment and
vehicle availability.
Certified arborists
and professional
urban foresters on
staff have some
professional
development but
are lacking
adequate staff
levels or adequate
equipment.
Multi-disciplinary
team within the
urban forestry unit,
including an urban
forestry professional,
operations manager,
and arborist
technicians. Vehicles
and equipment are
sufficient to
complete required
work.
Equipment for the program is adequate. The staffing level is low due
to the current transition period.
Funding
Appropriate funding in
place to fully implement
both proactive and
reactive needs based on
a comprehensive urban
forest management plan.
Funding comes
from the public
sector only and
covers only reactive
work.
Funding levels
(public and private)
generally cover
mostly reactive
work. Low levels of
risk management
and planting in
place.
Dynamic, active
funding from
engaged private
partners and
adequate public
funding are used to
proactively manage
and expand the
urban forest.
Funding is currently allowing Urban Forest Services to complete
reactive maintenance and begin transitioning to cycle pruning.
Disaster Preparedness &
Response
A disaster management
plan is in place related to
the City's urban forest.
The plan includes staff
roles, contracts,
response priorities,
debris management and
a crisis communication
plan. Staff are regularly
trained and/or updated.
No disaster
response plan is in
place.
A disaster plan is in
place, but pieces
are missing and/or
staff are not
regularly trained or
updated.
A robust disaster
management plan is
in place, regularly
updated and staff is
fully trained on roles
and processes.
Urban Forest Services plays a significant role in the City-wide storm
response plan.
Page 269 of 299
117 Appendix D: Sustainability Indicators
Communication
Effective avenues of two-
way communication
exist between the City
departments and
between city and its
citizens. Messaging is
consistent and
coordinated, when
feasible.
No avenues are in
place. City
departments and
public determine on
an ad-hoc basis the
best messages and
avenues to
communicate.
Avenues are in
place but used
sporadically and
without
coordination or only
on a one-way basis.
Avenues are in place
for two-way
communication, are
well-used with
targeted,
coordinated
messages.
Avenues for communication are in place, but workloads interfere
with a high level of messaging.
Page 270 of 299
Appendix E: Community Survey 118
Appendix E: Community Survey
1. Trees are important in San Luis Obispo for the following reasons (choose your top 5).
Response
%
Number of
Responses
Shading/cooling 61.8% 398
Community character/aesthetics 58.5% 377
Wildlife habitat 54.8% 353
Improving air quality 53.9% 347
Connection with nature 46.6% 300
Quality of life 46.4% 299
Reducing urban heat island effects 42.6% 274
Greenhouse gas reduction 35.3% 227
Reducing energy needs 16.8% 108
Reducing stormwater runoff 15.7% 101
Reducing stress 14.4% 93
Enhancing pedestrian/bike corridors 13.4% 86
Screening/creating privacy 8.5% 55
Increasing property values 6.4% 41
Reducing health incidence/cost 4.5% 29
Increasing retail sales 1.7% 11
Safety/reducing crime 1.4% 9
Other (please specify) 2.2% 14
All of the above; I should not have to choose just 5.
Carbon sequestration
Providing beautiful shade
this entire list are my reasons
promoting sustainability and nature
We need to improve the how do I say this the overall canopy. We need
more instead of cutting down native trees for housing. They need to be
replaced with natives not ornamental
Climate Control
Urban Wildfire Interface Defensive Planning-Veg Mgmt
Really, aren't all of the above important? I think so.
Natural Beauty
The trees are terrible for the city. The sidewalks are popping up very dirty
and it changes the attitude of people in the city to not take care of our city
it is filthy along with the shoe polish
Traffic Calming
Life all life! Trees aren’t important they are essential? Who’s writing these
questions???
Total
644
(0 skipped)
Page 271 of 299
119 Appendix E: Community Survey
2. What do you feel is the most important environmental benefit from trees (choose one)?
Response
%
Number of
Responses
Greenhouse gas reduction 22.1% 142
Shading/cooling 21.3% 137
Reducing urban heat island effects 20.2% 130
Improving air quality 18.3% 118
Wildlife habitat 13.4% 86
Reducing stormwater runoff 2.8% 18
Other (please specify) 2.0% 13
All of the above; I should not have to choose just one.
All of the above
All of the above. You're not giving us the opportunity to tell you what
trees REALLY mean while you're chopping down hundreds all over the city.
my feelings are irrelevant, no need to choose when they do all, this is a
silly question
Oxygen production
Trees absorb carbon and give off oxygen. We need all the ways of
absorbing carbon we can find to combat climate change/global warming.
Trees are just plain good.
the calming, beneficial, aesthetics valley of living beings that offer nothing
but wholesome good feelings and a critical vital connection with our
creator that instills comfort, warmth and security.
Don't make me chooooooose!
Reducing urban heat AND shading, cooling
Everything. Trees are essential for all of the above reasons!! Essential for
all life!
Overall benefits of nature - all of the above
Total 644 (0 skipped)
3. What do you feel is the most important socioeconomic benefit from trees (choose one)?
Response
%
Number of
Responses
Community character/aesthetics 32.8% 211
Quality of life 24.2% 156
Connection to nature 16.6% 107
Reducing energy needs 11.5% 74
Enhancing pedestrian/bike corridors 3.6% 23
Reducing stress 3.1% 20
Increasing property values 2.3% 15
Reducing health incidence/cost 2.0% 13
Screening/creating privacy 1.1% 7
Increasing retail sales 0.6% 4
Safety/reducing crime 0.5% 3
Page 272 of 299
Appendix E: Community Survey 120
Other (please specify) 1.7% 11
All of the above. STOP THE MASS tree cuttings!!
again, really? its a fact, has socioeconomic benefits, no need to choose
You can't separate the affects of trees socioeconomically because it's all
connected to human/nature . One affects the other spiritually, psychically
socioeconomically
Shading/cooling
Shade and protection from rain for our homeless neighbors
all of the above
Berries all over the cement
There could be more than one socioeconomic benefit.
wildlife habitat-including bees and other pollinator insects/birds
Life!!!! All life dies without trees. Is this a real survey?
Total 644 (0 skipped)
4. Where do you think it is most important to plant more trees (choose up to 3)?
Response
%
Number of
Responses
Neighborhood streets 77.3% 486
Parks 54.5% 343
Open space 40.9% 257
Medians 34.7% 218
Retail areas 29.3% 184
Arterial roads 28.9% 182
Other (please specify) 7.6% 48
Along bike/walking paths
everywhere
udeveloped lots
Maintain mature trees on new construction
Everywhere - you've cut down so many we won't be able to replace them
for decades.
everywhere we can!
everywhere
If you replace trees in one area you need to replant in that area. Also
instead of cutting down trees when building find a way to build around the
trees. Make them or it a part of the landscape of the new building
projects
New neighborhoods
Schools
SCHOOLS
Schools
Schools
In new housing or commercial developments
All of the above
Page 273 of 299
121 Appendix E: Community Survey
Schools
Razed developments
Waterways
Downtown
Stop removing so many tree @ new developments
Anywhere there isn't much nature, aka wherever there's concrete.
Trees provide cooling in overly concreted areas, and in every area if they
are allowed to grow large enough.
Parking lots
Parking lots
ALL the above
Replacement of trees removed for disease or public safety wherever they
may be.
Everywhere we can
Between freeways & neighborhoods
All of the above reasons
Schools! There is hardly any shade at the schools
Parking lots
Everywhere possible.
AWAY FROM HIGH VOLTAGE ELECTRIC DISTRIBUTION LINES
All of the above
Anywhere they’re less likely to be involved in wildfires?
Pedestrian and bike lanes
Parking lots that are giant asphalt islands
all new construction...speaking of where is all the water going to come for
all the new construction? And where is the affordable housing?
Private property where trees can be maintained year round.
Everywhere there is room to plant!
Only plant trees of you can take care of them and water them
Arterial roads should be downgraded and made pedestrian-friendly with
trees planted
in traffic circles/bulb-outs/medians/etc. Trees/plantings should be used as
traffic calming devices.
Please plant trees in medians where you can also provide pedestrian-
friendly infrastructure (stop signals, crossings, flashing lights). Trees in a
well-designed median don't do much to encourage walking for streets that
are a hundred feet wide.
All of the above
Silly question
All of the above
Open spaces should be left as natural as possible, if no trees in them
naturally, don’t add them
Total 629 (15 skipped)
Page 274 of 299
Appendix E: Community Survey 122
5. What are the best ways to encourage tree planting on private property (choose up to 3)?
Response
%
Number of
Responses
Free or low-cost tree 72.0% 453
Rebate on water bill 61.2% 385
Rebate on purchased tree 49.4% 311
Tree species and site selection information 45.0% 283
Community tree planting event 34.7% 218
Other (please specify) 7.0% 44
City support on recommended trees and locations
Let's protect the mature trees we have and not allow their removal.
PLEASE!
Low cost native and/or drought-tolerant trees, rebates on property tax
All of the above
Discourage developers removing mature trees, financial incentives to plan
and build around existing trees
Allowing only minimal cutting of trees for a development project will
encourage others to plant trees knowing they won't be removed
Low cost maintenance agreement
Free food
Lawn sign or decal "Proud Participant in the SLO 10,000"
Native plants/drought resistant
Rebate/Free tree trimming
Requirement Assoc w new construction, remodel, etc
Tree pruning and fire defensive planning is essential
education and replanting requirement
$ incentive for individuals or small businesses, city money shouldn't pay
for corps to green wash.
Tax rebate
Tax incentive
To have a awesome City tree crew and program
Clear planting and maintenance guidance
The city could water the trees for 2 years w/recycled water as done at
Laguna Lake Park.
Having the City plant the trees, with permission of property owners, and
perhaps with offering a few different tree choices
Free or low cost native tree
Follow up after the tree planting (All of the above!).
offer assistance with tree maintenance & care
All of the above
on going tree maintenance after new planting
Tools to succeed: example Irrigation kit?
Education on which species support NATIVE wildlife AND a financial
incentive for native species
Page 275 of 299
123 Appendix E: Community Survey
Education about importance of trees for birds and wildlife
Include edible trees in selection (citrus, feijoa, loquat, mulberry, etc...).
Homeowners value fruit producing trees.
Free pruning
Massive volunteer effort to plant trees. Use CP and Cuesta volunteers.
Photo contest
Free or low cost trimming & raking when necessary
education on why we want people to plant trees
Don’t allow developers to remove mature trees for subdivisions
Na
Tree species and site selection ASSISTANCE (consultation, not just
information)
I don't know how much encouragement people need, people enjoy having
trees and seem to do a good job of planting them on their property if it is
appropriate.
Provide planting service
Not sure we s/b encouraging potential fire hazard
I would say rebate on water bill-but that should only apply for native
plantings that won't increase water usage over the long run
Start by talking to people, information is key. Stop putting out surveys
that give people the opportunity to rate essential things as though they
weren’t.
Consider free or low cost fruit trees for private property
Total 629 (15 skipped)
6. Describe your awareness and/or interactions with San Luis Obispo’s urban forest program (check all that apply).
Response
%
Number of
Responses
I have seen City crews working on trees 70.3% 423
I was aware that the City responds to tree emergencies 52.8% 318
I did not know the City had a program to care for trees 25.4% 153
I have used the City website or called for tree information 20.4% 123
I have read an article in The New Times or The San Luis Obispo Tribune
about trees 15.6% 94
Other (please specify) 9.0% 54
I have volunteered at tree related events 8.3% 50
the importance of city arborists I have called the Davey group in response to a flier they left offering tree
service on our powerlines and they did not return a call nor show up until a
year later
I learned about it through my GIS class! Taken classes in dendrology and surveying and became familiar with
forestry and management practices in the area
Page 276 of 299
Appendix E: Community Survey 124
I have taken a Urban Forestry class at Cal Poly
I took Urban Forestry at Cal Poly
I know people on the Tree Committee.
Need to maintain all mature trees in new construction!!!!
Too many trees removed for development
I have been involved as a citizen in promoting the urban forest program I have seen many trees removed for urban development when they could
have been incorporated into the plan.
Attended the arbor day event with my sons school
Certified arborist who has tree issues with neighbors I have seen the city approve cutting down massive numbers of our urban
forest trees I received a city notice of meetings. I have been talking to people about
trees in area I live that new building cutting down trees. I've been
concerned and didn't know who to talk to. There's a big oak and granite
right next to where I live and building is planned. I do not want to see this
removed. I've been in cities that literally include trees and granite stone
within the buildings they've built. We have made it too easy just to
bulldoze things down because it's easy way out. We need to understand
the connection to nature. Our survival depends on it.
the city keeps cutting down trees
Many mature, local trees have been cut down for development.
I heard about the program through EcoSLO We have a huge oak on property and use tree care professionals once a
year
My Dad use to be the manager for parks, buildings, and street trees for SLO.
Have planted trees at arbor day event at Mitchell park Attempted to increase more wildland fire interface veg mgmt awareness at
city boundaries and roadway shoulders I was told the city waters street trees, but I rarely see it happen--should
happen more often.
A BUDDY WORKS THERE
I was liaison to Tree Committee during terms on City Council
I have looked into preventing sycamore planting bc I'm allergic to them.
I have attended a tree committee meeting.
The city has trimmed trees in our neighborhood parkways. why does the Tree Committee allow removal of the vast majority of trees
that come before them? Why does the city of slo allow developers to
remove so many beautiful mature trees & then plant small ones. The GHG
& Climate Change seriously necessitates protecting our mature trees for
many science based reasons. The city is a huge tree killing machine!
Went befor the tree committee. I have been to a tree committee meeting and know how strict & difficult
the City is with removing and planting trees I knew there were people that maintained them, but didn't know about the
urban forest program per se.
Page 277 of 299
125 Appendix E: Community Survey
My children's school participated in an Arbour day art contest and tree
planting event They planted trees in neighborhood. I wish every street was like Mill street,
beautiful tree lined streets
I don't think there's much awareness of the program I am an arborist and nearly applied to apply for an open position in the
urban forestry group in the past.
Trying to remove a tree causing major property destruction at my office.
The city arborist called me
I saw former mayor Heidi Harmon post about it
Served as liaison to Tree Committee from City Council.
Though a Cal Poly urban forestry class Unfortunately, there are a lOT of trees not maintained...all along Johnson
by French Hosp, Bowden Ranch open area. Dead trees down...fire concern.
Member of Tree Committee for 8 years
I had to work with Ron on a building permit tree requirement.
Na
I have attended Tree Committee meetings organized a tree planting event, been to street tree comm. meetings, had to
get permission to remove trees, my tenant dated the last street tree
guy.......
The city cannot take care of of what they have now I have used the Cal Poly tree/attribute list for evaluation of street tree
options
Trees planted with memory plaques I have a colleague who serves on the City's Tree Committee and has
informed me how tight of a budget the City has to care for all of its
beautiful trees. We need to incentivize private investment in trees (by
individual homeowners and businesses) to help offload some of the future
maintenance obligations.
None. This survey has been enlightening
I am aware they exist but have seen no activity
I am aware that there is a program but have not seen it working. Total 602 (42 skipped)
7. What is your satisfaction with the level of care provided for community trees?
Response
%
Number of
Responses
Somewhat satisfied 38.4% 231
Neutral 32.1% 193
Completely satisfied 12.8% 77
Somewhat dissatisfied 11.1% 67
Completely dissatisfied 5.7% 34
Total 602 (42 skipped)
Page 278 of 299
Appendix E: Community Survey 126
8. Do you feel that urban forest services and programs are equally accessible to all residents?
Response
%
Number of
Responses
Not sure 63.3% 381
No 20.3% 122
Yes 16.5% 99
Total 602 (42 skipped)
9. What topics of education and outreach interest you (check all that apply)?
Response
%
Number of
Responses
Tree list/what tree should I plant in San Luis Obispo 84.6% 509
Irrigation/watering during drought 73.9% 445
How to plant a tree 47.7% 287
Benefits of trees 46.5% 280
How to hire a tree care professional 28.4% 171
Other (please specify) 6.5% 39
Come look at my HOA and help us decide about our trees.
SLO City staff needs to be educated about benefits of keeping the trees we
already have and not replacing them with trees that will take decades to
reach the size and advantages of the ones they killed.
More discussion of tree removals for development
Stop cutting down mature trees on all new construction!!
How to stop or minimize tree destruction currently happening during
urban development.
Identify problem trees and remedy
How to care for and prune a tree
People understand trees. Find ways to reduce water cost because the city
has increased water rates after encouraging saving water.
how to avoid cutting trees down
Where to plant trees, how much space is needed
stop cutting down trees. developments can build around them
Benefits of planting more fruit trees.
By
All of the above
On-site school education
Home tree/City boundary/Roadway area defensive veg mgmt for wildfire
protection of neighborhoods
provide tree information (like root damage to roads/sidewalks) for various
trees that can be planted.
Clarity on rules for neighborhood roadside trees, creek side trees support
for replacing trees with native trees
Page 279 of 299
127 Appendix E: Community Survey
How to accelerate tree planting throughout the County to achieve ghg
reduction
Tree list should specify soils requirements for particular trees, natives
should be encouraged.
It seems like native trees like the Coast Live Oak can survive better during
droughts & climate change. Our tree committee is pathetic. They're
aligned with developers & tree killers.
none interest me
emphasize California native trees - educate public Doug Tallamy videos
None; I rent and can't afford the time nor a place
Support for trees on residential properties
I wish the city would help take care of the planter boxes that are in the city
right away, I live on Lawton street and most of the curb planter boxes are
weeds and it looks terrible. I wish there was some incentive for the home
owner or the city to take care of this space and would be nice if it had a
uniform look.
All of the above.
How the city incorporates awareness of facilities that can be negatively
impacted by trees.
Tell me about all these health benifits.
Educate developers to plan development around existing trees.
NA
I know what I am doing
Na
support people who have a tree issue and not charge them if desiding the
free shoud be removed
impact when mature trees are cut for developers
We’re American we don’t need anymore stinking tree in fact if we kill
them all we’ll have more room for people and stuff. Too if we get rid of
all the trees we’ll likely wipe out our homeless problem. They already
have no indoor respite so making the outside even more unbearable will
aid the City in their current efforts of “anywhere but here.”
None
None
Clarity about tree removal and re-plantings
Total 602 (42 skipped)
10. Optional. Please use this space for any additional comments about San Luis Obispo's urban forestry program.
If the City values trees so much, why are so many trees being allowed to cut down in the project off of
Highland Dr.?
More trees please
I support urban forestry. Too many trees are cut down for and by developers. Some of your questions
were loaded and the forced choices were sometimes insufficient.
https://www.facebook.com/TreesDoc
Page 280 of 299
Appendix E: Community Survey 128
We must make protecting our mature trees a priority. It is no longer prudent to cut down mature trees
and replace them with trees that won't serve us well for 20 years into the future.
Let’s be very careful about eliminating existing healthy trees for the sake of new developments. Very
important that any replacement trees be of significant size and quantity (more than equal to those
removed!) to enhance the project.
I think it is time to find a species of tree to start replacing the ficus trees downtown that are tearing up
sidewalks.
prevent developer removing quality mature trees
Maintain a level of staffing and funding to meet Arbor Day Foundation recommendations.
The program should also work to remove invasive species when possible from public places and encourage
private citizens to replace them with native species.
Get rid of the cattle fields in the city limits and replant that land with native trees. I’m thinking of the
field/hill along broad, between orcutt rd and tank farm.
community outreach is very important and i love the possibilities of there being some incentive and
community aspect in planting trees
More accessibility for the public to plant trees/care for them and know what kinds of trees encourage our
local habitat.. Maybe monthly community tree planting with different chapters around SLO county.
why isn't the city watering the trees in our parks, they are dying!
Please plant more female trees on city streets, excessive male trees are serious allergy issues.
I am concerned that too many mature trees are being removed and their surrounding ecosystems are
damaged for new construction projects.
Stop approving new housing and retail development that requires taking down significant numbers of
trees. Encourage creative designs so that existing trees can be maintained for environmental and visual
esthetics.
There are posts in social media that the City is removing over 1000 mature trees to accommodate
development. I don't know if it is true or not, but perhaps more information could be provided to the
public about tree removal programs.
Work w the city to leave more ‘set back’ space between streets and homes, offices, etc. Demand architects
& builders don’t skimp on green areas, that is, less concrete & MORE trees & plants as a buffer.
Trees in the down town go through a messy stage & the merchants/city does not clean up the pods/leaves
that drop. Garden street is the cleanest due to merchants/owners cleaning the sidewalks.
I walk to work and there are a lot of messy trees. It would be beneficial to focus on planting trees that are
not so messy along sidewalks. Also adding additional trees along residential quarters. The shadiest street is
Pacific on my route but I typically walk on Islay and Buchon.
Really sad that the city is allowing developers to completely eradicate mature trees and not making them
replace with older trees, just making them plant super young trees that have no benefit to wildlife or air
quality or reduce greenhouse emissions for years. No removal of older trees should be allowed unless they
are diseased.
The city shows its bias for developers and the funds new development provides by allowing hundreds of
mature and healthy trees to be removed in recent years. SLO City staff is saying one thing and showing
complete disregard for the trees already in the city if they're in the way of development.
The city requires a property owner to get permission to remove a tree, requires replacement planting, but
never checks to see that the replacement planting has taken place.
The city in some parts of town have used tree trimmers for city trees that appear to lack basic knowledge
about how to prune large trees - for instance the block of Chorro between Marsh and Higuera - second for
instance the liquid amber street trees in my neighborhood that were trimmed in a way that opened them
up, left long branches with growth only near the ends that then let the branches "bounce" much too much
on windy days and encouraged broken branches.
Page 281 of 299
129 Appendix E: Community Survey
And to partially repeat - it is "criminal" that so many mature trees have been sacrificed in recent years
(Righetti Ranch, Avila Ranch, San Luis Ranch, etc.) to satisfy the greed of housing tract developers who
aren't even local.
Please preserve existing mature trees whenever and wherever possible, especially in new developments.
I am very concerned about the destruction of trees along city’s riparian corridors. Proper planning and
design could have saved these trees. New residential development even to meet state mandates for local
financial support, should take a back seat to saving these trees. The urban forestry program is will be
unable to offset the loss of mature trees by supplanting with immature trees for years to come.
The city allowed the cutting of many full grown trees for housing developments. The new developments
could alter their plans to save more full size trees. I’m aware the city will require planting of trees. The
new trees will take years to be full grown. The city doesn’t walk the talk with trees.
The trees on downtown Higuera are beautiful. We need more streets like it.
Please don't remove any more trees in the city in the name of development. Design any future
developments around any mature trees, our environment is counting on the city to do the right thing.
Why isn’t the Slo urban forestry more involved with planning and development expansion into formerly
open spaces (either private or public) where tree removals are proposed. Shameful planning process when
the removal of mature trees is/are a part of. ….
All approved removal of trees on new construction should be stopped immediately!!!!
While there may be an urban forestry program, I cringe every time I pass a new development where
existing mature trees/habitat have been destroyed to allow for maximum density of units abetted by the
unchallenged cooperation of city government. Progressive cities like ours should lead the way in tempering
our desire to provide additional housing with the restraint necessary to keep from destroying the very
reason we love our community.
SLO is allowing too many mature tree removals and tiny trees planted in their place which does not
sequester carbon amounts the mature trees did. This will work against Climate Change efforts that are so
important. Too many trees are killed for development with the City’s permission.
PLEAE STOP THE MASS TREE REMOVALS. YOU HAVE ALREADY DESTROYED HABITAT AND ARE CAUSING US
TO PUT THOUSANDS OF POUNDS OF CARBON IN THE AIR DAILY. SHAME ON YOU!!!
love that street trees have been planted by cutting holes in concrete on sidewalks. plant more trees in
medians and roundabouts, add speed humps to streets to slow down vehicles.
stop approving developments which cut down mature trees and replace with small trees
Developers should be required to save old growth trees and also plant more trees as part of the
development.
Stop allowing tree removal.
I live 2 blocks from CalPoly and there is constant building in the area. I am aware of the preferences for
infill building and ADUs, but I constantly see that trees and yards are allowed to be removed and built
upon. This is an older neighborhood that contains many mature trees and gardens, many created by
professors of the past as a lasting legacy for the community. This legacy is fast disappearing, along with
the environmental and aesthetic benefits of trees and plants. Housing is important and I am aware of the
mandate to build, build, build; however the quality of our neighborhoods should be respected. If student
rentals are purely cement and stucco, what are we demonstrating to the leaders of tomorrow?
And basically, if there are no trees to breathe, then we cannot breathe either!
Also, Davey Tree is not one of my favorite arborists. I seldom see a tree cut by them that doesn't look
hacked and miserable.
Mature trees in the city need to be protected and preserved. Removing mature trees for development and
replacing with immature saplings needs to be avoided and incentives should be provided to developers to
preserve the existing urban forest.
Page 282 of 299
Appendix E: Community Survey 130
Return the Tree Ordinance to the strong ordinance it USED to be before Matt Horn destroyed the Tree
Ordinance. If you want to improve the quality of life for SLO residents, fire Matt Horn.
I love the city’s commitment to this important quality of life issue. Thank you!
We need more trees!! We love watching the animals use the trees! We moved here from Davis where the
tree canopy was extensive and we really enjoyed it!!
Not sure if it’s relevant but trees and sidewalks should be friends. There are places it can be difficult to
walk due to trees needing a prune such as along Sacramento street and along neighborhood sidewalks.
I have been surprised by permits allowing the complete clearing of mature trees on residential lots without
a requirement to replant equivalent numbers after building.
The trees chosen in the past have been terrible. Ficus nitida is the worst street tree you could find.
Camphor is beautiful but not appropriate for street trees. New buildings are being built that have no
setback from the street for trees. ???
Please don’t reduce the tree program! We need more trees!
Overall happy, but sad to see the large redwood at Amholm Park have its roots cut. I'm guessing it's a trip
hazard but cutting surface roots on a redwood is very damaging and it hasn't fixed the trip hazard. I would
be very upset if the tree died as a result of poor management. Please look into the care of that beautiful
redwood and help it out.
Due to proximity of monarch butterfly migration sites, we should include more nectar flower trees to give
them energy to make it to the overwintering sites.
We are blessed to live in an area that can support food bearing trees. We should plant several throughout
the city for citizen use. Including things like citrus, avocado, persimmon, etc.
more trees needed in neighborhoods with large streets/arteries like Ramona Drive. SLO Drive
neighborhood is so desirable because its got lots of big trees, which are charming and healthy and
represent quality of life.
With water costs, how does the community get trees established with proper irrigation.
Tree form selection, upright canopy vs. multi low branching is critical to long term success.
the city used to water trees and now it doesn't anymore, why?
Loss of new trees is discouraging (e.g., to gophers, poor watering during establishment), so ramping up
with successful early plantings seems important
It has been shocking to see so many trees needlessly cut down. Developers can work around nature and
not have to clear-cut.
I'm not informed enough on what is presently being done. I only know we do need to improve our canopy.
I don't want to see city use pesticides/herbicides and I'd like to see public better educated on their use and
negative affects on human Flora and fauna.
there is no urban forestry program. when a developer wants to clearcut trees the city allows it. the city
also does not follow its own rules about requiring additional trees to be planted with new development
There is a low hanging branch of a tree on the sidewalk of Stenner street that could be a potential hazard.
Please preserve mature trees and speak up about their preservation during the development process.
In older neighborhoods, city trees were planted that have caused damage to sidewalks, driveways,
foundations as well as excessive leave/ needle litter that clog storm drains.
I think there should be an effort to plant more fruit trees in public spaces. As long as we're making an
effort to increase urban forests, why not plant something that we can eat? Free fruit to anyone willing to
harvest it. What a concept!
I don't think that many people, especially students in SLO, know about the urban forestry program and
how they could interact with and utilize this program. I might be unaware if there is any, but I think this
program should find more ways to connect with Cal Poly.
Please consider planting native tree species for new plantings. They will thrive in our climate and support
wildlife
Page 283 of 299
131 Appendix E: Community Survey
Many trees should be planted in new neighborhoods like San Luis ranch
Very disappointed that folks remove trees from parkways and do not replace. It seems if trees are
mandated for parkways, then there should be some enforcement of this mandate.
Is there a volunteer program with the urban forestry in slo?
I think another incentive would be for the city to cover cost of ripping out concrete in sidewalks for tree
placement. I would really like to see the city encourage planting of natives as much as possible. These have
a much greater benefit for wildlife and are best adapted to our environment. Perhaps incentives could be
larger for native plantings.
In Cambria we have several well educated and capable tree specialists who assist in permitting, removal,
maintenance etc. our trees. Thank you for this opportunity to chime in.
Thanks for caring for the trees. Does the city provide water for trees in open spaces, such as the many oak
trees? I heard many are dying due to drought conditions.
I want to see protection for all oaks and mature trees when new subdivision permits are granted. Case in
point: the removal of oaks by wealthy winery owner in 2015 in North SLO county.
Thank you for reaching out to the community. Please look at our public school's needs for trees. Many of
the school sites in SLO can benefit from more trees.
I would love more trees! There are a lot of places where tall weeds grow on the sidewalk
that the city should be maintaining— just want to make sure we take care of what we have too :)
There is a huge lack of trees at schools. Blacktops are SO hot and there is no shade for students. ECo Slo
had FREE trees for Pacheco this year and they would not take them. We tried to facilitate planting but the
school would not allow them. Too much work or concern with kids climbing? City should impose same
requirements on schools as homes. They must have trees. Look at an aerial of any neighborhood and it’s
the most grass, least tree area. Crazy. I think you could add hundreds of trees to our school and make a big
impact.
The more outreach the city does regarding their tree policies and general tree care BMPs (both for
community as well as private trees), the more the residents will benefit.
Glad this is a topic of conversation. Trees are so necessary! Please add more to the schools. After so much
construction at each site, the trees were the first to be moved to give room for the new facilities.
I would like to see wood from trees cut down to be repurposed for furniture, instruments, or art
Street trees need to be planted in established residential areas where trees are lacking. The lack of trees in
the historic and downtown areas are a good example.
The more trees the better
I think we really need to focus on planting more trees in our city especially at our schools. Our youth need
to see the process of planting a tree and the care if provides from a educational stand. We also
DESPERATELY need more shade at our elementary schools
First off stop cutting down the “urban forest” because a developer can’t figure out how to design a project
around mature trees regardless of the are “native” or not. Maybe the City needs to read the it’s Land Use
Element a little more carefully. It’s says new development is supposed to respect existing trees on the
project site. I don’t think cutting them down is what is meant by respect.
Proper pruning is crucial for shaping the canopy. So many trees in town have been butchered (esp the
sycamores). Please have educational opportunities for local landscapers to learn how to care for local
trees.
The Urban Forestry Program needs to be part of a City standing taskforce/working group with Fire
Department/Parks Dept/Public Works to conduct wildland fire interface vegetation management projects
along open space boundaries, roadway right of ways and city boundaries with areas such as Cuesta Park to
reduce ladder fuels and maintain defensible space in the event of wildfire
The street tree in front of our house is barely surviving. The city is supposed to water and take care of it,
but I doubt they are doing anything. How do I contact the SLO urban forestry program people?
Page 284 of 299
Appendix E: Community Survey 132
Who is responsible for sidewalk repair when city tree roots raise/break sides?
I’d like to see easier outreach and info for caring for trees, and the rules surrounding trees esp “sidewalk”
trees and support for re planting w drought tolerant natives
Regarding trees only in the downtown core: they are very poorly managed and trimmed. The primary goal
of these trees is to provide shade, not just to look pretty. The more shade, the longer people will linger
downtown, providing an economic benefit to businesses. Trees are trimmed far too high above sidewalks
and the street; doing that reduces shade in mornings and late afternoons. When trees are removed they
should be replaced with larger trees than saplings. There are two types of trees downtown. One type
provides nice shade, the other does not. Those scraggly trees should be replaced by the better shade
species. There are far too many gaps between trees on many streets. Plant more trees! Line the streets.
Our trees are what makes downtown SLO unique, for the shade the trees provide.
I am extremely grateful for SLO's urban forest.
It is why I shop here rather than in surrounding communities--
all the shady parking.
And I brag on that very benefit every chance I get.
I have lived in over a dozen communities in 8 states, and SLO has by far the most satisfying, soothing,
calming presence of all.
In my opinion, you can never have too many trees!!!
Thank you, SLO urban foresters!!!
Give a higher priority to keeping existing trees when permitting new development.
Please stop allowing development plans to cut so many trees. Make plans fit into the site, not try to
remake the site.
The City should consider (and promote if it exists) a program/fund/bank that allows private property
owners to pay into when on-site replacement to offset tree removal isn’t feasible or appropriate due to
soil type, topography, or other property constraints. Not all lots in SLO should have trees. I haven’t
removed a tree that requires a tree removal permit that was planted too close to my house which is in a
fire hazard zone because my lot doesn’t have any suitable spots for the replacement requirements. I’d be
very happy to pay a fee that supports the replacement at 1:2 or more in a more appropriate location
somewhere else in SLO. This plan should identify the preferred and most suitable locations that maximize
benefits to the environment and community.
Species list for street trees should be revisited. Add more options, but be aware of pollen allergy ratings!
(looking at you sycamore, I can't go outside in my neighborhood during windy days in spring since
sycamore were added a few years ago). Native trees are best. Drought tolerant are a must. Trees with
flowers are nice, ie crepe myrtle, jacaranda, the ones w yellow flowers in the creamery. (Not mimosa trees,
I'm also allergic. It's a sad life.)
I'm not a big fan of the particular street trees downtown. I like trees, just not that overwhelming? It was a
great idea to plants them in the 50s (sad we can't see the mountains, but benefits make it worth), however
now they are huge! Destroying sidewalks and dominating historic facades. Also, if your dog eats enough of
those seed pods they get diarrhea. :(
Planting trees in open spaces is great! If budget were unlimited I'd say definitely do that. Since that's not
reality, my focus would be on areas human's hindered nature (with structures and paving). More trees in
parks is also a plus, but I feel like y'all are already pretty good at that.
I love trees and I'm excited to see where the City goes from here! Thank you for the survey!
Please stop removing large trees from the downtown areas. We've lost so much shade, cooling benefit
and character in these losses. It seems tree removal is very easy for anyone who seeks it. Replacing trees
with a much smaller tree will take decades to provide the same benefits. Look at the character of a place
like Carmel, CA where large trees grow in the middle of neighborhood streets. Traffic is calmed
dramatically, shade is abundant and cooling is easy to find. We keep removing our assets!
Page 285 of 299
133 Appendix E: Community Survey
I would be happy to be involved as a taxpayer
Because it is hard to get a tree removed (permits and cost) it would be nice to mail new homeowners a
tree planting guide. Most nee homeowners will plant a tree- but they don’t know what they’re doing.
I worry about tree removal for developments, especially older trees that are well established. Too many
older trees are removed and ‘replaced’ by young, non natives. Many die and are not replaced after they
die
I have two trees planted at the Commemorative Grove for my deceased parents.Does the city’s Urban
Forestry program still maintain these trees?
I have only seen one young man out there. There wasn’t anything in the survey about this wonderful
program. I hope it will be a priority in the future!
Full staffing is vital.
I think that adding 10,000 new trees is a good start, but we should be more ambitious with our goals to
transform our city into a beautiful space with plenty of shade, beauty, and animal life that will help sustain
us through the difficulties to come from climate change
The Urban Forestry program has NOT been staffed for over one year. Only one interim city arborist and
one part time temporary tree worker. They have only recently renewed a contract service provider that is
based out of Ventura. There is nothing safe or efficient about the current program.The current state of our
street trees/urban forest is literally an accident waiting to happen. Please look up ISA best management
practices!!
Please check the irrigation system for the oaks along the railroad safety trail.
Too many mature trees are cut down to make it easy for developers, instead project design should be
guided to protect them. It takes years to replace their value with new planting.
Tree planting requires continuous community engagement, volunteerism, and stewardship beyond what
our small City Urban Forest Services team can provide. Therefore, our community would benefit from a
dedicated tree planting organization like Portland's Friends of Trees. https://friendsoftrees.org/
How can the City foster the growth of such an organization?
Removal of the mature and varied species of trees at Palm & Nipomo is an outrage as is removal of trees at
the Westmont property. There is no more park-like parking lot than at Palm & Nipomo. Replanting with
immature trees requires more water & provides fewer benefits of all kinds for many years until the trees
mature.
The last 3+ years of the SLO Urban Forestry program have been severely understaffed and underfunded.
Either hire 4 full time crew members, or contract it all out. Sidewalk impact from tree roots is a major
problem - cheaper to fix by in-house crews? As downtown trees age and need replacing, more $$$ will be
needed....
I would love to see an emphasis for the City to plant native trees. In my neighborhood (Sinsheimer) we
have street trees that in not doing well because they are not native and they are infested with aphids. I
would also love to see more natives (trees and shrubs) planted in our parks. Meadow Park is a good
example of a great park with amazing trees (it's a hotspot for birds!) and it could also benefit from even
more native trees and shrubs there. Sinsheimer Park could also become a better habitat for
birds/pollinators with better tree selection. Thank you!
We need a really well-qualified City Arborist that has a 4 year university degree & perhaps advanced
degrees. You're selling our trees short. Remove Allan Bate, the lead tree killer from the tree committee.
He intimidates and manipulates the others and is the alpha dog.
There is not a 3 person crew! 1 part-time, temporary employee and a interim City Arborist.
Please be truthful in the way you present this to the community
Refrain from cutting trees downtown
I recently had to remove a tree on our property. The process was good. The tree committee members
listened, the arborist was helpful, and it was easy to see that the city is working to maintain trees citywide.
Page 286 of 299
Appendix E: Community Survey 134
We should take a hard look at the species approved for planting within San Luis Obispo.... Native species
are drought tolerant instead of exotics from outside our bio zone...
I would love to see a whole lot less of sprawling parking lots and a whole lot more of city open
spaces/small parks with trees.
Education of the public about how important native trees to the area are, also what is your soil, what tree
is appropriate for your space, how to care for it.
I'm not clear what this survey is supposed to do. Is there really a "debate" about trees? Or are you just
looking for "well, 99% of the people who responded to the survey said they support trees!"
Someone broke a new tree in Islay Park. The city cut it to the stump, but I hope they replace it. Sad that
people vandalize things.
Thank you for wanting to Plant more trees. They take years to mature. What you plant today will be fore
the next generation.
We have had many trees cut down in our neighborhood (on City property) over the past five years. All due
to the trees becoming damaged during strong winds. But the City has never replaced one of these trees!
Don’t they require it of residents who wish to remove their trees? Our property value and our enjoyment
of our home and neighborhood continues to decrease with each tree the City removes and does nothing
replace. We get more freeway noise and more light pollution (headlight pollution, to be specific) with each
removed tree. This survey is so limiting as far as being able to say what topics really matter, so I wish I
could say more, but this one issue in particular really hits home and bothers me greatly!
We have such a beautiful city due to the planting done so long ago. I'm concerned about the cutting down
of trees for all the development going on. These are mature trees going away, and even if we plant
something new, it pales in comparison. We need to plant bigger trees so they can replace those gone
missing. Also, downtown is amazing in large part to the trees/cover. It would be great to expand that
further from the center out to the neighborhoods, and further up the main roads. Also, for the new
development, they should have to plant a mixture of mature and smaller trees.
So happy to see the trees in Laguna Lake getting some much needed trimming, with the dredging project.
We love our trees! I know there are issues with the large ficus (?) trees downtown, but they really are
gorgeous and it is so neat to see such a large canopy.
How trees impact sewer and other infrastructure needs to addressed…funding to help take out root
invasive trees in neighbors along with utility under grounding in older Slo neighborhoods
Too many trees are planted without overhead power lines in mind. Also I see too many trees planted too
close to homes. This is worrisom. I would love to hear the plan on how the city is able to keep up with the
trees in neighborhoods that are encroaching on power lines, damaging foundations and roofs and keep up
with thousands of new trees.
I used to live on Branch Street in SLO - that’s one street where I would love to see dead trees removed so
that new ones may flourish. Avenues lined with trees give a homey, authentic ans welcoming feel - would
love to see more of that along Tank Farm or Higuera (also, where did all the higueras - fig trees- go?)
The trees on our street (Jeffery) are significantly over grown, dropping access in yards, and dropping limbs.
The city said we are not scheduled for trimming for 3+ years. I think there needs to be much more routines
matinence on trees to encourage more planting and keep them healthy.
Focus should be on native trees, and maintaining older growth vs removal.
The more trees the better. Ideally, less water intensive trees would be great across the city.
I'm retired and would love to volunteer to help with planting trees/maintaining trees/watering, etc. I think
it's a huge priority. I also think that there probably are many retirees like me who would be delighted to
volunteer to help establish/maintain an urban forest. You have an untapped volunteer base!
I am very interested in the potential for enhancing the synergies between the urban forest and
environmental education at all levels. Any enhancement of open space/urban forests should consider the
opportunity for student engagement and education programs addressing the topics of scientific method,
Page 287 of 299
135 Appendix E: Community Survey
climate science education, biodiversity/wildlife, and anything else identified by teachers in the county.
Also, any plans going forward should be laser focused on planning in a way that can be used as a model for
safe planting methods and decision making in the context of high voltage electric distribution/transmission
lines, both underground and above ground.
My HOA (Righetti Ranch) has discouraged residents from planting trees on private property! That should
not be allowed!
I wish there were more tree shaded playgrounds and play areas for children on hot days.
Thanks!
I would like to see an ambitious reforesting effort pursued on the City's hillsides. There are so many bare
or merely grass-covered slopes all around us, but it is clear that our climate (even during drought) can
support hillside forests. This seems to be the most effective way to both beautify our surroundings while
greatly contributing to carbon sequestration and habitat restoration. The age of widespread grazing is
over, but the damage caused by it has not yet been undone. Though street trees greatly contribute to the
well-being of residential areas, reforestation of our hillsides would seem to be the most effective
investment in the long-term.
It is gratifying to witness the maintenance of our trees, although I believe that budget restraints have
meant that our creek/riparian corridor has been neglected in the last 15 years. I remember the community
service program using the labor of corrective institutions to help trim the trees, which benefited the
laborers and the community and nature.
Please use more reclaimed water for maintaining trees and parks.
I was somewhat reluctant at doing this survey given what I consider the reckless destruction of our urban
trees by the city council. The removal of trees for development is constantly justified as necessary to meet
the state housing act. What is also stated to rationalize it is the intent to plant trees elsewhere to replace
these. The fact that "elsewhere" is a place unlikely to be visited or seen by people seems to be a missing
part of the conversation. We need to keep our urban trees for people and other living things that need
them. If we want wildlife in our cities we need to keep our trees. Heck with the state housing act - do you
know how to say No?
If an expert could come to your home and tell you what kinds of trees to plant and where to plant them,
that would be amazing!! I definitely would plant more trees in my front and back yard if I know what and
where!
The city has done a poor job with tree replacement at our parks. Many have been removed because of
disease or damage with no replacement. Many are poorly trimmed or not at all and they grow awkwardly.
Many residents take trees out without permission. Need enforcement and monitoring the tree companies
that do this.
It is essential for our community to have healthy and abundant trees in all areas. Please do not use the tree
survey as a tool to limit trees or to bolster extreme tree trimming. Thank you.
City-owned property backs up to my property and tree branches reach across into my yard. What types of
maintenance will the city do on these trees?
I think the downtown trees on Higuera are nuisance trees. They bring flies and ruin sidewalks, and the
newer look on Monterey street is much cleaner, easier to navigate and more appealing. I know its not
popular to say this but please remove the trees along Higuera in the shopping district!
A lot of people hate the mess and maintenance on trees. How about access to tree maint. And
landscaping. Especially for the old and others that physically cant.
Reducing energy is an environmental benefit, not socioeconomic…
I heard it’s going away and will be contracted out. They were nice people. Sad the city doesn’t care about
having professional staff anymore.
SLO needs lots more tree cover. SLO needs to stop allowing developers to essentially clear cut well-treed
sites. The city needs to have more respect for wild things that live in and depend upon trees; I have seen
Page 288 of 299
Appendix E: Community Survey 136
city contractors trimming palm trees during owl nesting season, and have seen city repeatedly allow
cutting large trees where hawks nest. The willow habitats along waterways need to be protected; willows
need to be replanted there, and existing groves protected.
I would like the city to plant more edible trees (citrus, feijoa, strawberry/lemon guava, loquat, avocado, fig,
white sapote, persimmon, etc...) along pedestrian & bike paths (e.g., RRST is good candidate). This would
allow residents to better interact with and get value from our trees and paths. Additionally would be a
resource for our food-insecure population. Use the local California Rare Fruit Growers chapter as a
resource.
Trees are good.
There are several sidewalk and median areas where the trees have been abused or removed and never
replanted - e.g., Bishop St at the entrance to Terrace Hill.
I walk a lot in the city and open spaces and there is a need for more shade!
I’ve seen so many trees being cut down due to lack of proper management such as pruning. Old trees
providing crucial habitat ripped out for new construction with miniature trees being replanted. People
cutting trees without approval and no repercussions
If we focus planting efforts on NATIVE tree species, we can simultaneously create shade/privacy/beauty
etc. for people, AND protect biodiversity. It's a win-win!
I would like to see more urban forest staff performing much needed maintenance of our city trees.
when i visit a city without trees, i quickly want to leave it. please let's not make this our city. working hard
to educate on how, when to plant trees and offering incentives is a great idea for property owners!
however, where we will really see positive outcomes if the city is acting on the land they manage to plant
more trees. i'm also a strong believer that any new developments need to include not just landscaping but
trees, and ones that thrive in our SLO county environment.
The city urban forestry department is woefully underfunded. Subsequently tree maintenance is not
completed in a timely manor and the trees suffer for it. Urban forest staff is overwhelmed with duties and
cannot be proactive in programming. City inspection of tree protection measures during construction is
non existent due to short staffing. The city should have at least 3 urban foresters plus a 3 person tree crew
to attend to on call tree maintenance issues. Contracting tree crews for regular maintenance is a good
direction to go regarding keeping on schedule.
Need improvement on quality of tree maintenance services, arborists that are able to properly prune and
care for tree health - have seen soooo many trees butchered by tree crews, and killed due to improper
pruning practices.
Provide more funding for the Urban Forest Dept to maintain street trees - public and private. Incentivize
developers to retain large trees in new construction.
The more trees the better ! Part of ANY new residential or large commercial development must include as
many trees as possible, we need them to help us keep our air cleaner & to help us breathe!
Please plant trees and places benches to rest under the shade along the open space and the street on
Orcutt and Sacramento. That open area needs shade and benches. Thanks
Those huge ficus trees need to be trimmed way back and gradually replaced. They take too much water
and are out of scale with the Downtown.
We should consider those spaces outside the city limit but in our county also. They are part of fire
considerations for Slo city.
I am disappointed and feel this survey and effort is a bit late having already lost too many mature trees to
development.
Some of our major thoroughfares (Broad Street is a perfect example) are completely devoid of trees. Broad
Street is horrible — it’s like a freeway. I would love to see streets like Broad have medians fully lined with
trees, except where turn lanes are required.
Page 289 of 299
137 Appendix E: Community Survey
Trees are good. The more the merrier. Trees make sense. Do it. Protecting and promoting trees is working
with nature and that is the best guarantee of a healthy, wealthy, prosperous future. The presence of Trees
is the most quintessential expression of our own value and worth. By showing gratitude and respect for
the importance of trees we are showing our priorities and the importance of life and harmony with nature
as our greatest strength.
I love trees and I love forests! I think they have many benefits for communities and I love that the City of
San Luis Obispo is prioritizing trees and urban forestry!
I would love to see trees used to beautify artery streets (johnson, broad, santa rosa, LOVR), and provide
shade and protection to pedestrians/bicyclists.
By moving trees, bike lanes and pedestrians to the middle of these roadways we would see a huge
increase in non-motor transportation.
Glad you are helping the community gain the many benefits of trees. Thank you!
I’ll repeat, do not allow developers to remove trees. Require them to develop in such a way to preserve
existing trees. What’s the point of planting new trees when mature trees continue to be cut down.
I appreciate how quickly a SLO urban forest employee responded when we had an issue with a tree on the
sidewalk near the driveway to our house (large, broken branch was hanging so low that we couldn't access
our driveway without possible damage to our cars).
I do love when trees separate pedestrians and cyclists from automotive vehicles too....
We love our trees and are excited for more to be in our public spaces. We feel that while most everyone
may have access to the Forestry Services, they may not be aware of that access.
the program needs better funding, haven't seen a street tree list recently, but in the past they have been
bad (poor choices)
Please educate homeowners about tree selection…let’s get away from plum and ficus trees or East-coast
natives and encourage more of our awesome and hardy native and adapted species!
This is wonderful - let’s plant many more trees! Broad Street between High and Orcutt feels like a highway
and is unpleasant for walking, yet is a key road to use to walk to the Coop, parks, etc. please improve with
more trees (and traffic calming)!!
I know people who say they are afraid to plant trees on their properties because if it turns out to be the
wrong tree for a location, it's almost impossible to get permission to remove it. Several people at a
neighborhood BBQ were in agreement.
If trees are so valuable to the City, why are you permitting a developer to cut down 50 trees off of
Westmont Dr.?
The City should have an aggressive street tree planting and maintenance program. We cannot rely on
homeowners and renters to take care of street trees.
We need more trees. The benefits are immense
Thanks for making trees an important part of the city plan!
The more trees, the merrier!
I hope the city plants as many trees as possible
It would be helpful to include a link on the City website to selectree.calpoly.edu or other similar Matt
Ritter selection tool.
I am not sure what can be done about tree roots that cause sidewalks to be unsafe, but it needs to be
addressed. I believe it can make the city vulnerable to law suits from individuals of a litigious nature who
may trip over an uprooted portion of a city sidewalk.
Trees are important for humanity.
The tree maintenance program is much better in the retail parts of town but in the residential areas it is
lacking. Many street trees in our neighborhoods have gone many years without attention. It is showing
up in trees with dead limbs and misshaped trees due to wind damage.
Also the City is slow on removing dead trees in open spaces and in the street side. And even slower to
Page 290 of 299
Appendix E: Community Survey 138
replace that tree with another.
It would be nice to see a wider variety of trees. It seems to be when the city plants trees the are all the
same. Then a few years later they do a different tree. It is like they go to Costco and buy a bunch,
regardless location of the tree, then move to another variety.
need to place more trees in multi family unit housing, which are mostly surrounded by cement and low
income.
We use way too much fossil fuel maintaining the city's trees-I would bet that in the 30 years I've lived here
there has been a multiple of more carbon emitted by vehicles and power tools than any amount of carbon
our trees have captured. The same is true of how most businesses and residences (and all schools)
maintain their landscaping. The number of gasoline powered leaf blowers being used on sidewalks/parking
lots/streets is also kind of horrifying, especially considering many of those are also maintained by street
sweeping vehicles-public and private.
It's a travesty that the City has systematically been allowing for the removal of thousands of mature trees
for purposes of residential and commercial developments. The increased number of small trees planted in
their place will nowhere near provide the carbon sequester benefit for many years. I find it hypocritical to
act concerned about our Urban Forest while approving the removal of mature trees all over the city to
make it easier for a developer to build. We need to preserve our existing Urban Forest as well as continue
to plant trees to increase it.
mature trees shouldn't be swapped with small trees for developers. Development should build around the
trees = for example the trees on Madonna Road for the development under construction and the
proposed development on Westmont
Too many trees are being cut down for development.
I’m hoping that there’s integrity behind the reasons for creating a survey like this but hah! Will the city
leadership have us rate the importance of water next, can’t wait for that survey:)
We should plant more edible fruit trees as an inexpensive way to provide a social safety net
Efforts seem to be directed toward tree removal rather than planting. Questionable choices of street trees
allowed (oaks by American Riviera Bank).
I had two young trees in front of my house. Same species. One died because the other was stronger and
shaded it. They were planted too close to each other. Maybe more thought can be put into species and
spacing.
There are some very large trees on public and private land that present a clear and present danger to
nearby people, homes and other structures due to damage from storm events and age-related falling
limbs. How does the city address tree maintenance in those situations?
I'm SO happy the city cares to sustain and hopefully expand the urban forest.
It’s not advisable on downtown City sidewalks due to bird droppings, falling leaves, etc. although they are
attractive and provide shade.
Downtown sidewalks are a hazard due to tree roots pushing up the sidewalks. I have tripped/fallen &
ended up in the E.R. with injuries due to this. Sidewalks need to be redone & some trees need to be
removed.
Total 192 (452 skipped)
Page 291 of 299
Page 292 of 299
City of San Luis Obispo INVENTORY OVERVIEW
Page 293 of 299
IMPORTANCE OF A TREE
INVENTORY
It is important to accurately
identify the trees within an
agency’s urban forest. Knowing
the quantities, locations,
species types, and health
conditions of these essential
assets within the community
provides the foundation for
which annual work plans and
budgets are based. Therefore,
having an inventory is critical to
the implementation of an
effective tree care program.
As of June 15, 2022 the data in
ArborAccess determined that
the City of San Luis Obispo’s
inventory consisted of 12,970
owned tree sites located
throughout streets, parks, and
facilities while including data
collection of stumps and vacant
sites. Examples of some of the
information collected for each
tree site is listed below:
• Tree Site Address
• Tree Species Identification
• Diameter Range
• Utility Presence
• Recommended Maintenance
• Removal Priority
• Height Range
• Condition
• Tree Health Concern
• Parkway Size/Type
June 15, 2022
1
City of San Luis Obispo INVENTORY OVERVIEW
Page 294 of 299
+
TREES
12,455
PLANTING SITES
379
RECOMMENDED REMOVALS
127
+ STUMPS
134
2
June 15, 2022
TOP 10 SPECIES & VALUE
Page 295 of 299
June 15, 2022
3
DBH HEIGHT
Page 296 of 299
ROUTINE TRIM
Routine Trim/Grid Trim (10,156 trees)
Regardless of the amount of a community’s tree management budget, systemic tree maintenance
reduces costs in the long term. There are 10,156 trees identified and recommended for routine
trimming. Systematic tree maintenance programs reduce the need for “emergency” maintenance,
help prevent liability problems (such as dead or weak branches that could fail), reduce tree mortality
and improve urban forest health and real value over the long-term.
A systematic tree maintenance program is comprised of pre-designed trimming grids which are
inspected and trimmed as needed in their entirety on a set schedule. By trimming trees on the
street, regardless of size, every resident in that community feels that they have received a service
for their tax dollars. At the same time, the safety and welfare of the community will be enhanced.
*Trees can present a serious safety concern, especially
larger, mature trees. Because many agencies assume
responsibility for a safe public right-of-way, any negligence for
the care of trees impacting the safety of the right-of-way may
fall on the agency. However, by implementing a
comprehensive tree risk management program, the agency
can take steps to limit their liability while keeping the public
safe.
Benefits of Grid Trimming
• Scheduling
• Improved Public Relations
• Equitable Service
• Preventative Maintenance
4
Patrol - Diseased or Declining (114 Trees)
These 114 trees are in decline due to environmental conditions, pests, disease problems, or due to
natural senescence. At the time of data collection these trees had not reached the point where
removal was necessary. In some cases, the condition of these trees may be improved by trimming,
watering, or improved by application of plant health care practices. It is recommended that these
trees go through a process of disease identification and treatment prescription and be patrolled to
determine the timing of treatment and application, or when removal is warranted.
Trim - Poorly Structured (29 Trees)
These 29 trees have been identified as having structural defects that can be improved through
structural pruning. These defects can include codominant stem trees requiring reduction cuts to
reduce the likelihood of failure. This can also include end weight reduction cuts to improve structure.
Young Tree Maintenance (1,703 Trees)
These are newly planted trees that have not been established or had stakes removed yet. These
trees need monitoring, watering, re -staking, fertilizing and structural pruning. This typically ends
when the stakes are no longer needed and they work type should be transitioned to a routine/grid
trim.
June 15, 2022
• Improve Health
• Maintain Capital Asset
• Reduced Liability*
• Efficient Record Keeping
Page 297 of 299
REMOVALS/ INSPECTION
Removal - Stump
(134 stumps)
Removal - Diseased or Declining
(20 trees)
Twenty trees were identified as diseased or
declining and are declining due to pest
infestations, disease or natural senescence.
Removal - Dead Tree
(59 trees)
Dead trees are identified by their species names
where the species can be determined. If they are
not identifiable they are called "Dead Tree." All
dead trees should be scheduled for immediate or
routine removal unless they are considered for
preservation to create suitable wildlife habitat
where conditions for public safety are not a
concern.
Removal - Poorly Structured
(12 trees)
These twelve trees have potentially hazardous
cracks or structural problems that present above-
normal safety concerns, and the potential for tree
failure cannot be mitigated through pruning. Other
examples of poorly structured trees are those that
have included bark located in a primary branch
attachment, which greatly increases the potential
for limb failure in the future.
Removal - Overhead Spacing Criteria
( 1 tree)
Maintained by other agency or HOA
(327 trees)
June 15, 2022
Removal - Seedling or Volunteer
(35 trees)
Trees meeting this criteria were not
intentionally planted by homeowners; they
were grown from seeds, from surrounding
5
Inspect - Recommended Removal
(1 tree)
One poor condition Sweetshade tree has
been recommended for removal by our tree
crew. It may not benefit from plant health
care techniques, and should be viewed by
City staff.
Page 298 of 299
June 15, 2022
6
The inventory data collected suggests the following
maintenance recommendations which should be
verified by staff.
1. Grid trim schedule to prune all trees on a routine
cycle (Most agencies average between 3 to 5
years).
2. Initiate inspection and mitigation for trees
identified to need patrolling for disease or
decline.
3. Removal plan (evaluate WCA, Inc.
recommendations and determine the agency’s
priorities for phased removals or other
mitigation).
4. Planting plan to fill vacant sites.
5. Provide young tree maintenance to ensure
proper establishment.
CONCLUSION
This information is considered to be a valuable reference for
future budget and maintenance projections. Your Area
Manager and WCA, Inc. can help you create these
projections.
PLANTING
Tree Planting (379 sites)
Based on the criteria provided by the City, WCA, Inc. identified 379 vacant sites that are suitable for
planting. Identification of vacant sites during the inventory collection allows the agency to expand
the urban forest and may assist in obtaining additional grant funding. Vacant site listings from the
inventory can be generated to create work lists and utilized for budget projections. The planting
palette should be referenced when determining the appropriate species to plant based on the
concept of “right tree, right place.”
Page 299 of 299
City of San Luis Obispo
Tree Committee Meeting
February 27, 2023
City Tree Committee Meeting
February 27, 2023
San Luis Obispo Community
Forest Plan
Recommendation
1.Receive a presentation on the Draft Community Forest Plan; and
2.Recommend that the City Council approve the Final Community
Forest Plan at its April 4, 2023, meeting.
2
Acknowledgments
3
Background
▪Purposes of Community Forest Plan (CFP):
▪Provide a long-term vision and address operational needs
▪Part of SLO’s ambitious climate action planning efforts; included in
climate action plans (CAP), 2021-23 Major City Goals
▪Pre-work:Master’s in City & Regional Planning professional project
report (2022)
▪Information sources:
▪Davey Resource Group Organizational Assessment Report (2021)
▪West Coast Arborists City of SLO Inventory Update (2022)
▪Review of City documents, scientific literature, other cities’ plans,
historical archives
▪Interviews with 11 urban forestry stakeholders, mostly local
▪Ongoing collaboration with City Public Works staff
4
The City of San Luis Obispo is a community
identified and shaded by a diverse, resilient,
thriving urban forest.Relying on the
Community Forest Plan, the City actively
encourages participation in tree planting and
stewardship, preserves and protects trees, and
promotes public safety and tree health.
The Plan helps the City implement cost-
effective enhancement and maintenance of the
urban forest, increases public awareness of the
value of our community forest, and maximizes
its social, economic, and environmental
benefits for current residents and future
generations.
Urban Forest Vision
5
Community Forest Plan Goals
1.Maintain and expand San Luis Obispo’s urban forest to maximize environmental, social,
and economic benefits for all, while minimizing undesirable conditions
(Maintain/expand forest)
2.Adopt a “right tree, right place,” lifecycle-based perspective towards urban trees which
includes the planting, care, and end-of-life use of climate-ready trees in locations where
they will have the greatest opportunity to thrive (Sustainability/climate resilience)
3.Foster a spirit of collaboration between and within City departments that are involved in
urban forest management, as well as between the City and other local stakeholders
(e.g., community groups, nonprofit organizations, businesses, utilities, other cities, Cal
Poly, other State agencies) (Collaboration)
4.Educate and seek the involvement of City residents and visitors, including historically
marginalized groups, in order to obtain their interest and participation in creation of a
thriving urban forest. (Outreach/equity)
6
Relationship to Other City Documents
1.City General Plan (LUE, Conservation/OS, Parks & Rec, CASE)
2.Municipal Code Chapter 12.24, Tree Regulations
3.City Engineering Standards
4.CAPs and Financial Plan Major City Goals
5.Other:
A.Open Space Conservation Guidelines (2002) and Plans
B.Waterway Management Plan (2003)
C.Community Design Guidelines (2010)
D.Downtown Concept Plan & Mission Plaza Concept Plan (2017)
7
History
1770s onward –Patchy oak and
riparian woodlands quickly depleted
1870s-80s –Increased tree planting
movement in SLO (including eucs)
Downtown remained “largely barren”
until late 1950s beautification project
2010s –Reduced staffing; 8-10 year
maintenance backlog
2023 –National/statewide context of
increasing tree die-off from drought,
pests, disease
Source: Davey Resource Group SLO Organizational Assessment Report (2021)
8
Outreach Completed for Plan
▪Stakeholder interviews for Master's project report (Cal Poly IRB-approved)
▪CAP Natural Solutions forums (2022)
▪Ongoing stakeholder engagement
9
Source: City of San Luis Obispo, Office of Sustainability & Natural Resources (2022)
▪Davey Resource Group (2021):
▪Stakeholder interviews
▪Benchmark Community
Survey (644 responses)
▪E-mail to ~24 stakeholders
re:draft plan availability for
public review before Tree
Committee meeting
The proposed urban forest objectives and
actions should be informed by the CFP’s
vision, mission, and goals.
Implementation
10
Collaboration and Partners
Administration/Diversity, Equity & Inclusion DEI
Administration/Economic Development ECON
Administration/Information Technology IT
Administration/Sustainability & Natural Resources SNR
Community Development CDD
Fire Department FD
Parks & Recreation (Ranger Service; Volunteer Coordinator)PR
Public Works PW
Utilities UT
California Polytechnic State University, San Luis Obispo (Cal Poly)
California Department of Transportation (CalTrans), District 5
Coastal San Luis Unified School District
Downtown SLO (Downtown Foresters program)
The Environmental Center of San Luis Obispo County (ECOSLO)
Northern Chumash Tribal Council (NCTC)
One Cool Earth
Pacific Gas & Electric (PG&E)
Rotary de Tolosa
yak titʸu titʸu yak tiłhini Northern Chumash (ytt)
Existing or Potential External City Partners (EXT)
Involved City Departments
11
Potential allocation of tree planting responsibilities, 2020-2035
Implementation (10 Tall Initiative)
Responsible Party(ies)Number of Trees
Allocated (Estimate)
City of SLO (Streets, Parks, Open Space,
Riparian Areas)
3,000
Public Works (Streets, Parks, Right-of-
Way, Facilities)
1,000
Natural Resources & Ranger Services
(Creeks, Open Space)
2,000
Standards for New Development 3,000
Volunteers and External Partners 1,500
Private Residents and Property Owners
through complimentary trees
1,500
Trees planted to date since 2020 CAP
(approximate)
1,000
Total 10,000
12
Source: ECOSLO (2023)
Outreach -Ongoing and Proposed
Publicizing the broad-spectrum benefits of a healthy urban forest through an
equity-based lens
▪Maintain Tree City USA certification &continue annual Arbor Day celebration
▪Continue to tie in with City marketing/tourism programs
▪Consider an urban forestry focus as part of City Earth Day celebration/events
▪Continue working with external partners (e.g., ECOSLO, Rotary, DT Foresters)
and bolster volunteerism
▪Explore working with Cal Poly/Cuesta to
create a student urban forestry corps
▪Pilot a complimentary tree program
▪Restart Commemorative Grove program
if/when possible, as additional sites and
resources are identified
▪Publicize Heritage Trees (e.g., webpage,
pamphlet, plaques)
13
Source: ECOSLO (2022)
Next Steps
▪Continue to catch up on maintenance backlog
▪Increase outreach and work with City partners to
implement the 10 Tall Initiative
▪Hire new City urban forest staff, when resources permit
▪Seek new sources of urban forest funding
▪Develop urban tree planting and lifecycle plans
▪Consider modifying engineering standards/municipal
code re: tree removals and mitigation requirements
▪Re-examine role, responsibilities, & authority of City
Tree Committee, as needed (“ambiguous”)
14
Recommendation
1.Receive a presentation on the Draft Community Forest Plan; and
2.Recommend that the City Council approve the Final Community
Forest Plan at its April 4, 2023, meeting.
15
Questions?
16Source: ECOSLO (2023)