October 2020 STANDARD INVENTORY ANALYSIS AND COMMUNITY FOREST MANAGEMENT PLAN Town of Greenburgh, New York Prepared for: Prepared by: Town of Greenburgh Davey Resource Group, Inc. Town Hall 295 S. Water Street, Suite 300 117 Hillside Avenue Kent, Ohio 44240 Greenburgh, New York 10607 800-828-8312 Davey Resource Group, Inc.1May 2020 TABLE OF CONTENTS Acknowledgments ............................................................................................................................................ ii Standard Inventory Analysis and Community Forest Management Plan Executive Summary ......... iii Introduction ....................................................................................................................................................... 4 Section 1: Structure and Composition of the Public Tree Resource .......................................................... 4 Section 2: Functions and Benefits of the Public Tree Resource ................................................................ 19 Section 3: Recommended Management of the Public Tree Resource ..................................................... 26 Conclusion ....................................................................................................................................................... 41 References ........................................................................................................................................................ 43 TABLES 1. Defect observations recorded during the tree inventory ..................................................................... 8 2. Pests detected during the inventory ...................................................................................................... 10 3. ROW trees noted to be conflicting with overhead utilities ................................................................ 15 4. Summary of benefits provided by inventoried trees ranked by species importance value .......... 22 5. Matrix 1. Likelihood matrix .................................................................................................................... 27 6. Matrix 2. Risk tating matrix .................................................................................................................... 27 7. Trees recommended for further inspection .......................................................................................... 31 8. Summary of estimated costs of the ten-year management plan ...................................................... 39 FIGURES 1. Estimated costs and workload for each year of the ten-year management plan. ............................ iii 2. Number of inventoried sites by type. ..................................................................................................... 4 3. Inventoried tree population distribution of most abundant species. ................................................. 5 4. Inventoried tree population distribution of most abundant genera. .................................................. 6 5. Inventoried tree population distribution of most abundant families. ................................................ 7 6. Public tree resource susceptibility to pests with a regional presence. ................................................ 9 7. Condition of inventoried trees. .............................................................................................................. 12 8. Relative age distribution of the inventoried trees. .............................................................................. 13 9. Condition of inventoried trees by relative age (size class). ................................................................ 14 10. Estimated height of inventoried trees in ten-foot increments. .......................................................... 16 11. Estimated crown width of inventoried trees in ten-foot increments. ............................................... 17 12. Estimated annual value of the functional benefits provided by the inventoried tree resource. .. 20 13. Estimated value of removing air pollution by weight and type. ...................................................... 24 14. Recommended pruning by size class and risk rating. ........................................................................ 29 15. Recommended removals by size class and risk rating. ...................................................................... 30 16. Routine pruning cycle by diameter class. ............................................................................................. 35 17. Young tree training cycle by diameter class. ........................................................................................ 35 APPENDICES A. Data Collection and Site Location Methods B. Invasive Pests and Diseases C. Risk Assessment/Priority and Proactive Maintenance D. Suggested Tree Species Davey Resource Group, Inc. i October 2020 ACKNOWLEDGMENTS This project supports the Town of Greenburgh’s vision to promote and enhance community well- being through public tree conservation and improved urban forestry management practices. This Standard Inventory Analysis and Community Forest Management Plan offers expertise in preserving and expanding urban canopy so the environmental, economic, and social benefits it provides continue for generations. Greenburgh is thankful for the grant funding it received from the New York State Department of Environmental Conservation (NYSDEC) in cooperation with U.S. Forest Service (USFS) through its Urban and Community Forestry (U&CF) Grant Program. The U&CF Grant Program is designed to encourage communities to create and support sustainable urban forestry programs throughout the United States. Greenburgh also recognizes the support of the following individuals and groups: Greenburgh Town Supervisor Paul Feiner Greenburgh Town Councilwoman Gina Jackson Greenburgh Town Councilman Ken Jones Greenburgh Town Councilwoman Diana Juettner Greenburgh Town Councilman Francis Sheehan Town of Greenburgh Conservation Advisory Council Town of Greenburgh Nature Center Greenburgh Department of Public Works Greenburgh Bureau of Engineering Greenburgh Department of Community Development and Conservation Notice of Disclaimer: Inventory data provided by Davey Resource Group, Inc. “DRG” are based on visual recording at the time of inspection. Visual records do not include individual testing or analysis, nor do they include aerial or subterranean inspection. DRG is not responsible for the discovery or identification of hidden or otherwise non- observable hazards. Records may not remain accurate after inspection due to the variable deterioration of inventoried material. DRG provides no warranty with respect to the fitness of the urban forest for any use or purpose whatsoever. Clients may choose to accept or disregard DRG’s recommendations or to seek additional advice. Important: know and understand that visual inspection is confined to the designated subject tree(s) and that the inspections for this project are performed in the interest of facts of the tree(s) without prejudice to or for any other service or any interested party. Davey Resource Group, Inc. ii October 2020 ERecommended Maintenance Types STANDARD INVENTORY ANALYSIS AND COMMUNITY FOREST MANAGEMENT PLAN EXECUTIVE SUMMARY The Town of Greenburgh Standard Inventory Analysis and Community Forest Management Plan focuses on quantifying the benefits provided by the inventoried tree resource and addressing its maintenance needs. DRG completed a tree inventory for Greenburgh in March 2020 and analyzed the inventory data to understand the structure of the town’s inventoried tree resource. DRG also estimated the economic values of the various environmental benefits provided by this public tree resource by analyzing inventory data with i-Tree Eco and recommended a prioritized management program for future tree care. The functions of Greenburgh’s inventoried tree population provide benefits with an annual estimated total value of $78,816. The town‘s annual tree maintenance budget is around $300,000, making Greenburgh’s return on investment 26% annually. The functions of Greenburgh’s inventoried tree population throughout its trees’ lifetimes are worth an estimated $29,530,838. Supporting and funding proactive maintenance of the public tree resource is a sound long-term investment that will reduce tree management costs over time. High-priority tree removal and pruning is costly and mitigation of these elevated risk trees accounts for the higher costs in the first year of the ten-year management program (Figure 1). Tree maintenance costs decrease after high-priority work has been completed and management transitions from reactive to proactive maintenance. Proactive maintenance also reduces the number of elevated risk trees over time by preventing deteriorating conditions of trees with initially minor defects. Therefore, budgets for later years are projected to stabilize around $273,090 as work becomes routine. Cost Grand Total Activity Grand Total (# of trees managed) $320,000 1,680 $310,000 1,660 $300,000 1,640 $290,000 1,620 $280,000 1,600 $270,000 Tasks Cost Over Time $260,000 1,580 $250,000 1,560 Year Year Year Year Year Year Year Year Year Year 1 2 3 4 5 6 7 8 9 10 Number of Maintenance Figure 1. Estimated costs and workload for each year of the ten-year management plan. Davey Resource Group, Inc. iii October 2020 Recommended Maintenance Types Tree Removal Total = 691 trees Extreme Risk = 0 trees Trees designated for removal