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HomeMy WebLinkAboutFrench Hospital Arborist Report_2_Oct 2020 GREENVALE TREE COMPANY October 28, 2020 Arborist Report For: Ariana Melendez Studio Design Group Architects, Inc. Site: French Hospital area beyond chain link fence southwest side of property beyond rear parking. Plant ID Eucalyptus globulus (Blue Gum Eucalyptus) Task Removal and reducing per FAA requirements. Definition: Transitional Surface – An area not directly below a flight path that allows for clearance on either side. Observations These are general observations. Individual trees may have some variance from these observations. Canopy – leaf color is good with no noted yellowing or fading. Tortoise Beetle has been feeding on lower leaves but likely not upper leaves as they are too high for habitat. Trees lower on the slope have canopies that are very high (top one-third to one-fourth of trunk). Branches – Some of the trees have longer branches subject to leveraged conditions. The trees on the top of the slope tend to have more branches and certainly lower branches. Branches of the upper trees are intertwined between trees and stems. Some branches on all trees have narrow crotches and included bark. Some stubs noted from prior branch breaks though these appear to be few. Trunks/stems – Trees can be single trunked and very balanced to multi-trunked with stems and weight leaning outward. The trees that are multi-trunked have very narrow angles between trunks and some of these have included bark. Trees at the top of the slope in general are not quite as tall as trees downslope. Heights of trees exceed 100 feet on most trees. Conclusion The FAA has concluded that these trees are exceeding height limits for medivac helicopters landing at the hospital. These trees are in the “transitional surface” near the flight path proposed for the FAA. The lower trees likely can be reduced to accommodate the height limitations. The trees nearest the parking lot cannot be reduced as there are no lower limbs to reduce to and the cuts would be so large that they would not close before decay and likely infection sets in. Recommendations Remove trees 389, 391 and 392 as these trees cannot be reduced without stubbing off stems. Reduce trees 337, 338, 348, 356, 359, 360, 363, 364 and 365. Reducing by 25 to 35 feet should allow compliance for FAA requirement. These trees should be reduced to an existing, well attached branch. Final determination will be made by the climber and site arborist. It may be that a few trees have no good branches to reduce to. If this scenario occurs, then a removal may be in order as this would be the best arboricultural practice. The trees that are reduced will need regular pruning maintenance to keep them at the required FAA height. Removal of smaller wood is always the best arboricultural practice. Management should be prepared to have these trees trimmed at least every three years. See drawing photos below for more information Sincerely Chris Stier, ISA Certified Arborist, #WE9262-A *diagnosis was made with observation, history and sound arboricultural and horticultural knowledge. It is always possible tha t other, or different problems exist that may contribute to the decline and death of plants. Further evaluation may be warranted if the steps above do not work. Pathology tests and other lab analysis are available. This (blue arrow) is the proposed flight path of incoming medivac helicopters. The trees in pink will need to be removed as they cannot be pruned to accommodate FAA “transitional surface” requirements. The trees in yellow will be reduced to accommodate the FAA requirements. Regular maintenance will need to be performed to maintain the requirements. This simple drawing illustrates the problem. On the lower trees we can reduce the tree to a branch (proper arboriculture practice). On the upper trees we have no branches to reduce the height to. Leaving a stub will cause multiple problems and likely lead to the decline of the tree or, if it gets growth, it would be very weak and eventually fail, possibly striking cars or people. In this case we need to remove the trees nearest the parking and reduce trees downslope FAA required tree height We are looking at trees 389, 391 and 392 here in this picture. They are the trees closest to the flight path and within “transitional surface” zone. These need to be removed. This is tree # 391. It’s very close to the parking and at the top of the slope. This tree exceeds the limit allowed for the FAA “transitional surface”. Note the trees downhill. Those trees can be reduced because they are further away and lower by being downhill. This is tree #392 and a good example of why three trees need removal. There is no place that the tree can be reduced to and meet the FAA requirements. Arrow is at approximate level of compliance. The tree with the arrow is #360. This is a tree down slope that will need to be reduced by about 25 feet. Somewhere near the arrow is where this tree will be reduced. There are many branches to choose from to select a good place to make the cut. This photo will give the viewer an idea of the slope’s steepness. This slope also makes the lower trees closer to the FAA requirements while the upper trees (from the perspective of the slope) are taller and would need to be cut much lower, actually stubbing the trees instead of lowering to a branch.