Tree Assessment Report Prepared for: Dr. Peter Giarrizzo 18 Franklin Place Pelham NY 10803

Transcription

1 Pelham Board of Education Tree Assessment Report Prepared for: Dr. Peter Giarrizzo 18 Franklin Place Pelham NY Prepared by: Ken Almstead, Certified Arborist NY 0335 Tree Risk Assessor Qualification (TRAQ) and Dan Groves, Certified Arborist NY 0188 August 12, Beechwood Avenue, New Rochelle, NY

2 Background: Ø In the summer of 2013, Pelham Public Schools (PPS) sought professional consultation by a consulting arborist based upon concerns it had about its tree population related to recent tree failures. Ø The site assessments produced a series of comprehensive reports all dated November 14, 2013 with recommendations which comprised of tree removal, testing and pruning. Ø Between November of 2013 and April of 2015 high priority tree removals and pruning (with some exceptions) were performed. Ø During this same time frame a district wide tree replanting set of plans were developed and a certain amount of trees were installed at various location under existing contract terms with two vendors. 2

3 Background (continued): Ø In early July of 2013, Almstead was contacted by the Superintendent of Pelham Public Schools to: a. Provide a second opinion regarding phase two and three tree removals and perform a site assessment of the tree population. b. Identify additional trees that may be at risk. c. Ascertain high-priority maintenance care based upon current tree health. 3

4 What is Tree Risk Assessment: There are three levels we use: Ø Level 1 Basic Ø Level 2 Limited visual assessment Ø Level 3 Advanced Arborists always use the following criteria to base their assessment: 1 Safety First 2 Then Health 3 Finally Aesthetics 4

5 Levels of Tree Risk Assessment: When approaching each location, we utilized previous tree inventories and report assessments provided as a template. Each property was separated into areas i.e. A, B, C etc. with individual trees numbered within that area. Ø Level 1: Limited to a visual assessment of an individual tree or a population of trees near specified targets used to identify specified conditions or obvious defects from a foot or vehicle perspective. Ø Level 2: Consists of a 360 degree, ground-based visual inspection of the tree crown, trunk, trunk flare, above-ground roots, and site conditions around the tree in relation to targets. An assessment shall include the identification of conditions indicating the presence of structural defects. Ø Level 3: Advanced level includes all Level 2 requirements employing methodologies used when the extent and severity of conditions or defect cannot be determined by a Level 2 assessment. Level 3 assessment may include, but are not limited to aerial assessment of branch or stem defects, evaluation of target risk, investigation of tree or site history related to possible or defined defects, lean assessment, probing, sounding and resistance drilling for decay with a Resistograph. 5

6 Performing Tree Risk Assessment for this Project: Ø For the vast majority of the phase 2, phase 3 and additional trees being recommended for removal we utilized an ISA Basic Tree Risk Assessment Form to document overall tree risk rating as well as mitigation options. Ø Where necessary, we incorporated additional Level 3 advanced testing which primarily consisted of aerial inspections with photography and internal decay tests employed with a Resistograph. Ø Photographs were taken for the purpose of identifying a contributing and supporting factor of the recommendations outlined for the tree/s described. 6

7 Observations & Testing: Ø Basic Tree Risk Assessment Forms were filled out for trees that had particular concerns or issues that needed to be addressed in detail. Ø Time frame is determined by what is an acceptable period in which to evaluate the likelihood of tree or tree part failure. For this project, a time frame of 2 years from time of inspection was established. Ø Target Assessment involved identifying targets that could be affected by the failure of the tree or a tree part. Targets were itemized and rated according to location, occupancy rate and the potential ability to restrict use in that area or move the target. Ø Site Factors such as history of failures, site changes, soil conditions, and exposure to weather events were taken into consideration. Ø Tree Health and Species Profile which details such particulars as vigor, pests, abiotic symptoms, and species failure profile were considered. 7

8 Observations & Testing (continued): Ø Load Factors include reviewing the trees exposure to wind in relationship to the trees crown size, density, branching structure and takes into account any recent or planned changes. Ø Crown and Branches which is comprised of the branches and leaf parts making up the upper structure of the tree were evaluated. Ø The trees Trunk which is comprised of the main woody axis of the tree was visually inspected from the ground for such issues as cavities, leans, included bark, codominant stems, cracks, insect and/or disease infestations, sapwood damage/ decay etc. If a main concern/s existed it was noted along with the load on that defects/s and likelihood of failure. Ø The Roots (trunk flares) or Root Collar (buttress roots) were examined in the same fashion. Ø The Risk Categorization matrix was recorded and assessed for Likelihood of Failure and Likelihood of Impacting the Target which when combined provides a direction for evaluating Consequences of Failure and an Overall Risk Rating. 8

9 Observations & Testing (continued): Ø If mitigation options of those risks are employed an Overall residual risk after mitigation is estimated. Mitigation may or may not lower the Overall Risk Rating. Ø If Advanced assessment is needed that is indicated as well as a Recommended inspection interval based upon the trees condition. 9

10 Observations & Testing (continued): 10

11 Observations & Testing (continued): 11

12 Observations & Testing (continued): 12

13 Siwanoy Elementary School Area B: Front of school building, west, Siwanoy Place is to the east, Town lot #14 is to the south and Town lot #12 is to the north Area B: Photographic Documentation Item #5 White oak (Quercus alba) 35 DBH Image 1: Location of the tree in front of the school. Slightly unbalanced crown northwest due to previous large tree removal southeast. Image 2: Change of grade made several years ago. Trunk flares are absent, cursory on-site excavation by hand led to discovery of adventitious roots. Recommending a root collar excavation (RXC) with an air spade to remove the soil and expose the primary root system. May also extend scope and relieve some of the soil compaction for this tree while tool is onsite. Pelham Board of Education Tree Assessment Report Ken Almstead & Dan Groves Almstead Tree & Shrub Care Co. 13

14 Siwanoy Elementary School Area B: Front of school building, west, Siwanoy Place is to the east, Town lot #14 is to the south and Town lot #12 is to the north Area B: Photographic Documentation Item #5 White oak (Quercus alba) 35 DBH Image 3: Cavity in codominant branch attachment southwest leader approximately 30 high. Inspect further. Image 4: Scar and wound at base northwest side. Again, this reaction wood would not have formed in this manner with this existing grade confirming that the grade was significantly raised in the past. Tree is under stress and showing signs of preliminary decline. Pelham Board of Education Tree Assessment Report Ken Almstead & Dan Groves Almstead Tree & Shrub Care Co. 14

15 Siwanoy Elementary School Area B: Front of school building, west, Siwanoy Place is to the east, Town lot #14 is to the south and Town lot #12 is to the north Area B: Aerial Inspection Photographic Documentation Item #5 White Oak (Quercus alba) 35 DBH Image 6: Shows depth of cavity. Image 5: Shows cavity at base of codominant leaders. Image 7: Shows weak attachments. This tree needs to be pruned to reduce stress on these points as well as the cavity. Pelham Board of Education Tree Assessment Report Ken Almstead & Dan Groves Almstead Tree & Shrub Care Co. 15

16 Siwanoy Elementary School 16

17 Siwanoy Elementary School Advanced Assessment: Resistograph Documentation Pelham Board of Education Tree Assessment Report Ken Almstead & Dan Groves Almstead Tree & Shrub Care Co. 17

18 Siwanoy Elementary School Summary: Area B: Item #5 White oak (Quercus alba) 35 DBH The oak is a specimen tree in a high profile area on the property. The change in grade is probably the most significant issue we have presently with the tree and it is impacting the overall health and vigor and it is showing signs of stress in color of foliage. The tree should receive a Root Collar Excavation (RCX) with use of an air spade to expose the primary trunk flares and those roots once exposed should be sounded or further tested. If we extend the use of this tool to other areas of the root zone to reduce soil compaction would be beneficial. A Resistograph test was performed at the area of the cavity at a 90 degree angle and sufficient holding wood was found. Proper pruning practices should be employed to reduce stress on this union. Recommendation Prune tree as prescribed and perform RCX with Air Spade and test roots for decay. Note: adjacent 12 sugar maple should receive a RCX as well at the same time; suspect severe girdling roots; non-biodegradable burlap still visible from time of planting. Pelham Board of Education Tree Assessment Report Ken Almstead & Dan Groves Almstead Tree & Shrub Care Co. 18

19 Prospect Hill Elementary School Area A: West of school building (front of school) south Washington Avenue, north Hudson Street Area A: Photograph Documentation Item #17 Pin oak (Quercus palustris) 30 DBH Image 1: Performing an aerial inspection; eastern branch left in photo extends over swing set. Image 2: Fruiting body of decay fungi. Image 3: Linear decay column with decay fungi present near base of crown. Pelham Board of Education Tree Assessment Report Ken Almstead & Dan Groves Almstead Tree & Shrub Care Co. 19

20 Prospect Hill Elementary School Area A: West of school building (front of school) south Washington Avenue, north Hudson Street Area A: Photograph Documentation Item #17 Pin oak (Quercus palustris) 30 DBH Image 4: Codominant stems higher in crown with crack at branch attachment. Image 5: Poor attachment at seam at base of codominant stems higher in crown. Pelham Board of Education Tree Assessment Report Ken Almstead & Dan Groves Almstead Tree & Shrub Care Co. 20

21 Prospect Hill Elementary School 21

22 Summary: Prospect Hill Elementary School Area A; Item #17 30 Pin oak (Quercus palustris) Tree was identified during visual ground inspection and was previously pruned in November of There is a swing set and play area directly southeast within the target zone of both branch and tree failure. At this time the tree was slotted for advanced assessment via aerial inspection due to decay observed from initial inspection. Inspection identified extensive decay in main trunk where several large scaffolding branches are attached which overhang target area. Further higher in the crown there exists a codominant union with an active seam and/or crack which is photographed and labeled above. In addition, fruiting bodies were observed within the immediate root zone surrounding the base of the tree. Additional root damage was observed on west side. While the risk on this tree could be mitigated through severe crown reduction and large branch removal the combination of these would greatly disfigure and compromise the integrity of the crown and jeopardize the overall health of the tree. Although biologically the tree appears to be of good health and vigor, structurally it has a combination of defects which warrant its consideration for removal. Recommendation Remove tree. Pelham Board of Education Tree Assessment Report Ken Almstead & Dan Groves Almstead Tree & Shrub Care Co. 22

23 Emerald Ash Borer: Ø Infestation by Emerald Ash Borer is inevitable in our region. Ø There are several ash trees that have been recommended for removal based on structural defects and the imminent infestation by EAB. Ø EAB is an invasive pest that has destroyed millions of ash trees in the U.S. since it found its way here from Asia. Ø It is estimated that about 900 million trees in New York will be lost to EAB over the next 15 years. Ø Methods that are used to control EAB include destroying infected trees, quarantining trees and firewood in regions with infestations, and inoculating ash trees to resist infestations. 23

24 Findings from Tree Risk Assessment: Ø We found that for the majority of the trees being recommended as a phase 2 or phase 3 removal were appropriately deemed as such and posed either; 1) An unacceptable level of risk over the time frame outlined given the targets involved and occupancy. 2) Were in a state of decline and/or of low vigor that despite mitigation would most likely not revert in health. 3) Are of an inferior invasive species or susceptible to inevitable demise from invasive pest, specifically Emerald Ash Borer (EAB). 4) Were of low profile in location or wouldn t be able to mature long term in the site which they were growing; i.e. rock ledge or outcropping or, 5) Were dead. 24

25 Findings from Tree Risk Assessment (Continued): Ø During our site assessments there were additional trees which were identified and documented for either: a. Removal consideration b. Further testing to be performed c. Pruning and/or mitigation of risk associated with such tree d. Site assessment considerations or, e. Significant high profile trees which required further analysis or discussion related to health or concerns other than to simply prune 25

26 Findings from Tree Risk Assessment (Continued): Ø We found that the overall maintenance of the tree population throughout the schools properties was to varying extents: a. Neglected over an unacceptable period of time for proper tree care maintenance and management. b. When maintenance pruning was performed by outside contractors it was not done to industry standards and was of substandard quality. c. Site improvements, turf maintenance and construction activities have occurred that had negative impacts on tree health and long-term preservation. d. Lack of management in controlling invasive species and preventing maturity of these trees especially in poor locations. e. Until recently, lack of a consistent and well-designed replanting for trees lost on a schedule in order to preserve the tree population and canopy coverage for future generations. 26

27 Recommendations: Ø Develop an acceptable time frame for work and activities to occur based on the highest priority items, risks involved, schedule and available budget considerations. Ø Perform consistent and scheduled Level 2 and Level 3, tree risk assessments and inspections in order to properly manage the tree population. Ø Develop a detailed scope of work with individual tree specifications through these inspections in order to schedule and provide well-thought-out maintenance. Ø Employ additional industry approved tree care maintenance practices that will improve vigor and preserve trees where and when permitted and acceptable. Ø That an arborist be consulted prior to any and all of the following activities: Changes in grade (higher or lower) with a trees root zone Trenching of any kind within same zone Construction of any kind especially related to soil compaction Movement of equipment and material storage or supply Impacts that will negatively affect tree health and vigor 27

28 Recommendations (Continued): Ø Utilize a well-designed and arborist reviewed tree planting program on a consistent basis in order to sustain and preserve the tree canopy and population. Ø Assign proper oversight to the program to ensure that industry standards are followed. Ø Vet all contractors for quality, experience, proper credentials and accreditations. 28

29 Role of Tree Risk Manager & Assessor: The Tree Risk Manager is defined as the tree owner, property manager or controlling authority. Their role, as assisted by the Tree Risk Assessor, is as follows: Ø Consider the duty of care. Ø Define and communicate tree risk management policies. Ø Determine the need to inspect the trees in question. Ø Identify the geographical limits of the tree inspection. Ø Explain target zone use. Ø Specify the desired level of assessment. Ø Establish the budget. Ø Decide the level of acceptable risk. Ø Establish the inspection frequency. Ø Determine the scope of work. Ø Prioritize work. Ø Choose among risk mitigation options. Ø Provide required information to the risk assessor. 29

30 Conclusions: Ø Many of the recommended second and third phase removals are warranted based upon the evaluation and testing performed by original consulting arborist Mr. Carmine Serpe as well as Almstead arborists. Ø While it is unfortunate to have to remove so many trees in such a short period of time, it is important to put the situation into context: The sheer volume of removals is a culmination of years of deferred maintenance and tree management. There are advanced techniques utilized by the tree care industry today that were simply not available a decade ago. The methodology of modern tree risk assessment relies on stages and levels of inspection and testing utilizing advanced techniques and tools. To our knowledge, this level of analysis and assessment has not been performed to this extent until recently. In relation to the overall tree population there is a remaining mature tree population that exists and moving forward you have the opportunity to maintain such a cherished and important part of the properties and community. 30

31 Conclusions (continued): Ø The removal of trees especially older ones, can often times be very controversial and a sensitive issue. It is recommended that the following be considered prior to commencing the work: Inform all concerned parties involved of the depth and analysis provided within this report and the results of the investigation. Would tagging of the trees to be removed be desired prior to removal? If desirable, publish a memo or article to faculty, students, parents and local residents as to the assessment performed and the tree replacement program which will be initiated. 31