GUIDELINES FOR URBAN FOREST RESTORATION 2 GUIDELINES FOR URBAN FOREST RESTORATION NEW YORK CITY DEPARTMENT OF PARKS & RECREATION http://www.nyc.gov/parks Acknowledgements: These guidelines were written over several years, based on decades of work by NYC Parks Natural Resources Group. Many people contributed who have not been listed below, and we acknowledge and appreciate everyone who took time to make this document more complete, accurate, and helpful to future restoration practitioners. The primary authors of this document at Parks were: Katerli Bounds, Michael J. Feller, Jennifer Greenfeld, Minona Heaviland, Clara Pregitzer and Tim Wenskus. Signifi cant written sections, review, and comments were also received from: Bram Gunther, Lea Johnson, Kristen King, Jacqueline Lu, Marjorie Naidich, Ellen Pehek, Brady Simmons, Susan Stanley and Ed Toth. External reviewers also contributed comments and notes that help to improve the fi nal document: Dennis Burton, Sarah Charlop-Powers, Richard Hallett, John Jordan, David Maddox and Josephine Scalia. We thank Commissioners Veronica M. White, Adrian Benepe, Liam Kavanagh, Joshua Laird, Fiona Watt, and Director Bill Tai for their vision and support. Consulting Team: Design + Planning Andrew Lavallee, Managing Principal, NYC Studio Gonzalo Cruz, Creative Design Director, NYC Studio Grace Miller, Designer, NYC Studio The consulting team would like to thank the following individuals whose participation was key to the develpment of this document: Hannah Beall, Jeremiah Bergstrom, Ellen Fyock, Caitrin Higgins, John Hunter, Lea Johnson, Renee Kaufman, Emily Neye, Shaun O’Rourke, Matt Palmer, Richard Pouyat, Thomas Salaki, Timothy Terway, Donna Walcavage, Adrianne Weremchuk and Evelyn Zornoza. Printed in the United States by Vanguard Direct. Printed on Cascades Rolland Recycled stock: Forest Stewardship Council (FSC) certifi ed, 30% post- consumer and FSC mixed paper, manufactured using biogas energy and certifi ed EcoLogo. Tabs Printed on Cascades Rolland Recycled stock: Forest Stewardship Council (FSC) certifi ed, 30% post-consumer and FSC mixed paper, manufactured using biogas energy and certifi ed EcoLogo 3 New York City Tree Canopy Map, 2010 GIS data 4 GUIDELINES FOR URBAN FOREST RESTORATION PART 1 BACKGROUND AND CONTEXT PART 3 BUILDING THE FOREST Chapter 1: Forest Restoration in New York City Chapter 5: Site Preparation 1. Introduction 9 1. Site Protection 84 2. Why Restore Urban Forests? 10 2. Invasive Plant Management 85 3. The History of NRG and Forest Management in New York City 12 3. Site Clearing 99 4. Case Study: Long-Term Forest Restoration at Alley Pond Park 18 4. Soil Preparation 100 5. Soil Placement and Amendments 102 Chapter 2: The Urban Forest: Restoring Structure and Ecosystem 6. CASE STUDY: Site Preparation Challenges in Rodman’s 104 Function to Natural Areas Neck North in Pelham Bay Park 1. Vertical Diversity: Multi-Storied Forest Structure and Its Function 24 2. Horizontal Diversity and Landscape Ecology 27 Chapter 6: Planting, Establishment, and Adaptive Management 3. Forests in New York City 30 1. Scheduling 107 4. Ecosystem Stability 34 2. Procuring 108 5. Challenges to Natural Forest Succession in Urban Ecosystems 35 3. Protecting 112 6. Case Study: Restoration Lessons from the Urban Forest and 37 4. Managing 114 Education Program (UFEP) 5. Adaptive Management and Research 116 6. Case Study: Incorporating Research into Reforestation 126 PART 2 PLANNING THE WORK Efforts at Givans Creek Woods Chapter 3: Site Inventory, Assessment, and Selection 1. Establish Goals 44 APPENDIX 2. Review Opportunities and Constraints 45 1. Regulations 133 3. Assess Sites in the Field 51 2. Common Forest Communities of New York 135 4. Evaluate and Prioritize Sites 56 City and Surroundings 5. Case Study: Assessing Sites: Opportunities vs. Constraints 58 3. Techniques for Control of Invasive Plants 142 4. MillionTreesNYC Sapling Mortality Datasheet 145 Chapter 4: Site Planning and Design 5. Web References 146 1. Goals and Objectives 63 6. References 148 2. Restoration Planning Considerations 64 3. Designing the Forest 66 4. Establishment and Adaptive Management 74 5. Case Study: PlaNYC Reforestation at Kissena Corridor Park 75 5 LIST OF FIGURES Chapter 1: Forest Restoration in New York City Chapter 5: Site Preparation Fig 1.1: Vegetation Types in Van Cortlandt Park, 1988 Fig 5.1: Site Preparation Time Needed to Control Invasive Plants Fig 1.2: Forever Wild Nature Preserves of New York City, 2007 Fig 5.2: Illustration of Methods to Control Invasive Trees Fig 5.3: Illustration of Methods to Control Invasive Shrubs Chapter 2: The Urban Forest: Restoring Structure and Ecosystem Fig 5.4: Illustration of Methods to Control Phragmites Function to Natural Areas Fig 5.5: Illustration of Methods to Control Herbaceous Plants Fig 2.1: Role of Restoration Principles Fig 5.6: Illustration of Methods to Control Vines Fig 2.2: Forest Structure Fig 5.7: Invasive Vegetation Treatment Calendar Fig 2.3: Forests in the Urban Matrix Fig 5.8: Illustration of Rototilling Fig 5.9: Illustration of Ripping Chapter 3: Site Inventory, Assessment, and Selection Chapter 6: Planting, Establishment, and Adaptive Management Fig 3.1: Restoration Site Selection Process Fig 6.1: Tree Planting Calendar Fig 3.2: Setting Goals at Different Spatial Scales Fig 6.2: Detail for Planting Container Trees Fig 3.3: Opportunities and Constraints Diagram Fig 6.3: Adaptive Management Cycle Fig 3.4: Review Site Constraints Diagram Fig 6.4: MillionTreesNYC Citywide Survival of Forest Restoration Trees Fig 3.5: Hutchinson River Parkway Plan Fig 6.5: Citywide Location of Mortality Plots Fig 6.6: Citywide Experimental Research Plot Design Chapter 4: Site Planning and Design Fig 6.7: Kissena Park and Willow Lake Experimental Research Plot Design Fig 4.1: Soundview Park Salt Marsh, Woodland, and Meadow Restoration Fig 6.8: Plot Design for Pelham Bay Park ULTRA-EX Research Project Fig 4.2: Elements of Restoration Site Design Fig. 6.9: Basal Area of Native Trees in Plots Fig 4.3: Administrative and Biological Timelines Fig 6.10: Tree Species Diversity in Plots Fig 4.4: Size and Packaging Choices for Plant Material Fig 6.11: Givans Creek Woods Species Planting Plot Design Fig 4.5: Estimates of Trees and Shrubs for One Acre Fig 6.12: Givans Creek Woods Soil Treatment Plot Design Fig 4.6: Visualizing 3 to 5 Foot Spacing Fig 6.13: Different Growth Rates Based on Soil Treatments Fig 4.7: Visualizing Restoration Over 25 Years Fig 6.14: Different Growth Rates and Survival by Species Fig 4.8: Site Categorization: Kissena Corridor Park Fig 4.9: Invasive Plant Removal: Kissena Corridor Park Fig 4.10: Kissena Corridor Park: Detailed Planting Year 1 Fig 4.11: Kissena Corridor Park: Detailed Planting Year 25 6 GUIDELINES FOR URBAN FOREST RESTORATION PART 1 PART 1 PART 1: BACKGROUND AND CONTEXT 7 PART ONE: BACKGROUND AND CONTEXT CHAPTER 1: Forest Restoration in New York City . 8 CHAPTER 2: The Urban Forest: Restoring Structure and Ecosystem Function to Natural Areas . 22 8 GUIDELINES FOR URBAN FOREST RESTORATION UFEP planting on Staten Island. PART 1: BACKGROUND AND CONTEXT CHAPTER 1: FOREST RESTORATION IN NYC 9 CHAPTER 1: FOREST RESTORATION IN NEW YORK CITY INTRODUCTION and ecological constraints hamstring conventional restoration practices. Over time, in the process of restoring more than 1,600 acres of natural areas, including 1,400 acres of forest, NRG has developed, borrowed, and shared new restoration Guidelines is a compendium of the theories and practices developed, implemented, techniques with a broad range of practitioners across the country. Key documents and tested during thirty years of natural area restoration by the New York City related to improving the practice of urban ecological restoration have emerged from Department of Parks & Recreation’s (NYC Parks) Natural Resources Group (NRG). this fruitful communication. Publications such as the Nature Conservancy’s Element The book includes an overview of the ecological and restoration principles behind Stewardship Abstracts, the Society of Ecological Restoration’s Management and NRG’s approach to forest restoration, as well as a step-by-step guide to building Restoration Notes, Leslie Sauer’s Once and Future Forest (1998), and an assorted sustainable urban forests. Though this information is presented through the lens of collection of conference and seminar papers have become cherished volumes in a NRG’s experience in New York City, the challenges confronting its efforts to establish slim canon of authoritative literature in the fi eld. NRG itself has published nearly 70 healthy forests here are found in most dense urban areas: a legacy of encroachment works, including articles, guides, summary reports, ecological assessments, and upon and neglect of natural areas, fragmentation, and the rampant spread of management plans. Until now, however, no single document has captured the full invasive plant species. Just as most local governments share these challenges, breadth of NRG’s forest restoration knowledge and experience. many also share New York’s commitment to creating a sustainable and ecologically robust urban environment. Forest restoration is a crucial step towards achieving that end. New York City Mayor Michael Bloomberg’s 2007 MillionTreesNYC reforestation initiative, with its goal of planting and caring for one million trees in New York’s fi ve boroughs by 2017, brought about a tremendous and instantaneous expansion of NRG, one of the nation’s fi rst publicly funded urban natural resources conservation