Forestry, Faculty of
DSpace
UBCV
Cheng, Zhaohua
Doctor of Philosophy - PhD
University of British Columbia
Cities are leading contributors to climate change while also suffering severe climate change impacts. In response, many cities have introduced climate change policies to guide the planning and implementation of local climate action. While most municipal climate action is focused on densification, building energy use and transportation, there is increasing recognition and integration of urban forests into cities’ climate change policies. However, the integration of urban forests may conflict with other climate measures (e.g., efforts to build compact communities), creating barriers to effective policy implementation. There is still limited understanding of the alignment and interactions among municipal policies relating to urban forestry, climate action, and climate-focused urban planning. This dissertation aims to address this research gap by conducting the following three connected studies. The first study examined the extent of alignment and integration between climate change policies and urban forestry policies in the 20 largest Canadian cities. Key policy gaps and discrepancies were identified across and within cities, especially in the use of terminologies, stakeholder engagement, maintenance priorities and practices. The second study aimed to identify key synergies and trade-offs in the policy-implementation-outcome spectrum of municipal policies relating to climate action, urban planning, and urban forestry through conducting semi-structured interviews with experts from Metro Vancouver, Canada. The findings highlighted significant trade-offs and synergies among policies, implementation processes and outcomes, especially in the areas of (re)development and infrastructure. The final study aimed to explore plausible urban forestry policy intervention solutions related to themes identified in the previous interviews. Modelled scenarios of urban form and urban forests in a hypothetical densifying urban neighbourhood were analyzed. Crucial urban greening opportunities on public and private land to better integrate urban forests into a densifying city for climate and livability benefits were identified and their relative impacts were discussed. The dissertation highlights important inherent gaps and conflicts among climate change, urban planning and urban forestry policies in cities that create significant barriers to successful outcomes. The findings can provide policy-makers, practitioners and researchers with useful evidence and insights on feasible pathways to make our cities more compact, green, climate-resilient, and livable.
INTEGRATING URBAN FORESTRY INTO COMPACT, CLIMATE RESILIENT CITIES: POLICIES AND PATHWAYS by Zhaohua (Cindy) Cheng B.Sc., The University of British Columbia, 2013 M.Sc., The University of British Columbia, 2016 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Forestry) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) April 2023 © Zhaohua Cheng, 2023 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the dissertation entitled: Integrating urban forestry into compact, climate resilient cities: policies and pathways submitted by Zhaohua (Cindy) Cheng in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Forestry Examining Committee: Stephen Sheppard, Professor Emeritus, Forestry, UBC Co-supervisor Lorien Nesbitt, Assistant Professor, Forestry, UBC Co-supervisor Cynthia Girling, Professor, Architecture and Landscape Architecture, UBC Supervisory Committee Member Patrick Condon, Professor, Architecture and Landscape Architecture, UBC University Examiner Sarah Gergel, Professor, Forestry, UBC University Examiner Additional Supervisory Committee Members: Cecil Konijnendijk, Director, Nature Based Solutions Institute Supervisory Committee Member iii Abstract Cities are leading contributors to climate change while also suffering severe climate change impacts. In response, many cities have introduced climate change policies to guide the planning and implementation of local climate action. While most municipal climate action is focused on densification, building energy use and transportation, there is increasing recognition and integration of urban forests into cities’ climate change policies. However, the integration of urban forests may conflict with other climate measures (e.g., efforts to build compact communities), creating barriers to effective policy implementation. There is still limited understanding of the alignment and interactions among municipal policies relating to urban forestry, climate action, and climate-focused urban planning. This dissertation aims to address this research gap by conducting the following three connected studies. The first study examined the extent of alignment and integration between climate change policies and urban forestry policies in the 20 largest Canadian cities. Key policy gaps and discrepancies were identified across and within cities, especially in the use of terminologies, stakeholder engagement, maintenance priorities and practices. The second study aimed to identify key synergies and trade-offs in the policy-implementation-outcome spectrum of municipal policies relating to climate action, urban planning, and urban forestry through conducting semi-structured interviews with experts from Metro Vancouver, Canada. The findings highlighted significant trade-offs and synergies among policies, implementation processes and outcomes, especially in the areas of (re)development and infrastructure. The final study aimed to explore plausible urban forestry policy intervention solutions related to themes identified in the previous interviews. Modelled scenarios of urban form and urban forests in a hypothetical densifying urban neighbourhood were analyzed. Crucial urban greening opportunities on public and private land to better integrate urban forests into a densifying city for climate and livability benefits were identified and their relative impacts were discussed. The dissertation highlights important inherent gaps and conflicts among climate change, urban planning and urban forestry policies in cities that create significant barriers to successful outcomes. The findings can provide policy- iv makers, practitioners and researchers with useful evidence and insights on feasible pathways to make our cities more compact, green, climate-resilient, and livable. v Lay Summary Cities are at the forefront of the fight against climate change. Urban forests, comprising trees and associated vegetation in the city, are increasingly recognized in municipal climate policies because of their roles in enhancing climate resilience and urban livability. This dissertation aimed to gain a better understanding of how urban forestry policies across Canada are integrated into various climate change and urban planning policies, and how these policies interact with each other. The research found significant discrepancies and conflicts among urban forest, climate action and urban planning policies, as well as their implementation processes and outcomes in Canadian cities. The dissertation also explored plausible solutions in a case study neighbourhood in Vancouver to better integrate urban forests into the process of building a compact, livable and climate-resilient city, thus assisting policymakers and practitioners in relevant fields. vi Preface All of the research work presented in this dissertation, including the identification of the research questions, designing the research process, data analysis, and manuscript/thesis writing, is primarily conducted by myself, with extensive guidance and support from my supervisory committee members – Professor Lorien Nesbitt (co-supervisor), Professor Stephen Sheppard (co-supervisor), Professor Cynthia Girling, and Professor Cecil Konijnendijk. I must also acknowledge the support from my collaborators on several components of the research work presented in this dissertation: ● In Chapter 2, the analysis of policy documents in French (specifically climate change and urban forestry policies from the City of Montréal, the City of Laval, the City of Gatineau, and the City of Longueuil) was conducted by Sophie Nitosalwski. While I was the lead author, she wrote 40% of the Introduction. ● In Chapter 4, the research work is based on spatially modelled urban form and urban tree data from the Urban Greening and Urban Densification (UGUD) Project (led by Professor Cynthia Girling). As a member of the UGUD project team, I have also received technical support from the other UGUD project team for data analysis, especially Dr. Yuhao Lu and Agatha Czekajlo. A version of the following chapters has either been published or is under review in peer-reviewed journals: ● Chapter 2: Cheng, Z., Nitoslawski, S., Konijnendijk van den Bosch, C., Sheppard, S., Nesbitt, L., and Girling, C. (2021). Alignment of municipal climate change and urban forestry policies: A Canadian perspective. Environmental Science & Policy 122: 14-24. ● Chapter 3: Cheng, Z., Nesbitt, L., Girling, C., Sheppard, S., Konijnendijk, C., Nitoslawski, S. (under review). Density and the forest: can and do they co-exist in a city? vii Ethics approval was required for the research work presented in Chapter 3. The ethics approval was obtained from the Behavioural Research Ethics Board of the University of British Columbia (certificate number: H20-03864). viii Table of Contents Abstract ......................................................................................................................... iii Lay Summary ................................................................................................................. v Preface .......................................................................................................................... vi Table of Contents ....................................................................................................... viii List of Tables ............................................................................................................... xii List of Figures ............................................................................................................ xiii List of Abbreviations .................................................................................................. xvi Glossary ..................................................................................................................... xvii Acknowledgements .................................................................................................. xviii Chapter 1: Introduction .............................................................................................. 1 1.1 Literature background ................................................................................... 4 1.1.1 Climate change and cities: from threats to opportunities? ...................... 4 1.1.2 Climate change and urban forests: opportunities for climate solutions or challenges to tree survival? .................................................................................. 7 1.1.3 Cities and urban forests: can a city be both compact and green? .......... 9 1.2 Research questions and dissertation overview ........................................... 11 Chapter 2: Alignment of municipal climate change and urban forestry policies: A Canadian perspective .............................................................................................. 14 2.1 Introduction .................................................................................................. 14 2.1.1 Climate change and urban forests in the Canadian context ................. 15 2.2 Methods....................................................................................................... 17 2.3 Results ........................................................................................................ 19 2.3.1 Overview of the study cities .................................................................. 19 2.3.2 Climate change policies: references to urban forestry and greening .... 22 2.3.3 Urban forestry policies: references to climate change .......................... 25 2.3.4 Alignment of policies: within-city comparison ....................................... 28 2.3.5 Governance context of climate change and urban forestry policies ..... 30 2.4 Discussion ................................................................................................... 31 ix 2.4.1 How are urban forests considered and integrated into climate change policies, and vice versa? .................................................................................... 31 2.4.2 Missed opportunities: policy gaps across and within cities? ................. 32 2.4.3 Limitations and future research ............................................................ 35 2.4.4 Implications for future research ............................................................ 36 Chapter 3: Density and the forest: can and do they co-exist in a city? ............... 38 3.1 Introduction .................................................................................................. 38 3.2 Methods....................................................................................................... 39 3.2.1 Study area ............................................................................................ 39 3.2.2 Interviews and procedure ..................................................................... 41 3.2.3 Data analysis ........................................................................................ 42 3.3 Results ........................................................................................................ 44 3.3.1 Synergies with urban forestry policy implementation and contributing factors ............................................................................................................. 45 3.3.2 Trade-offs with urban forestry policy implementation and contributing factors ............................................................................................................. 49 3.3.3 Solutions for addressing trade-offs ....................................................... 55 3.4 Discussion ................................................................................................... 58 3.4.1 Identified synergies and trade-offs among climate, urban planning and urban forestry policy realms................................................................................ 58 3.4.2 Discrepancies between synergies and trade-offs: problems in the policy-implementation-outcome spectrum? ................................................................... 59 3.4.3 Overlaps between synergies and trade-offs: where opportunities arise? 62 3.4.4 Limitations and future research ............................................................ 64 Chapter 4: Urban forestry policy interventions to create a walkable, green, and resilient city 66 4.1 Introduction .................................................................................................. 66 4.2 Methods....................................................................................................... 69 4.2.1 Study area ............................................................................................ 69 4.2.2 Selected policy interventions ................................................................ 74 x 4.2.3 Acknowledgement of contribution ........................................................ 80 4.3 Results ........................................................................................................ 81 4.3.1 Private jurisdiction: development-related urban forestry policy interventions ....................................................................................................... 84 4.3.2 Public jurisdiction: infrastructure-related greening policy interventions 91 4.3.3 Alignment with Vancouver’s current tree canopy target ..................... 105 4.4 Discussion ................................................................................................. 108 4.4.1 Urban forestry policy interventions for a walkable, green, and resilient city ........................................................................................................... 108 4.4.2 Important implications for establishing and managing urban forests .. 109 4.4.3 Limitations and directions of future research ...................................... 113 Chapter 5: Synthesis and Conclusion: possible pathways toward green, compact, and climate-resilient cities ....................................................................... 116 5.1 Research summary and overall contribution ............................................. 116 5.2 Synthesis of key results ............................................................................. 117 5.2.1 Are municipal climate change and urban forestry policies well aligned? .. 117 5.2.2 How do urban forestry policies interact with climate action and urban planning policies in the policy-implementation-outcome spectrum? ................. 118 5.2.3 What urban forestry policy interventions can cities take to better sustain their urban forests amid climate change and densification? ............................. 119 5.3 Limitations and future research ................................................................. 120 5.4 Final thoughts ............................................................................................ 123 Bibliography .............................................................................................................. 127 Appendices ................................................................................................................ 158 Appendix A.1 – List of climate change and urban forestry policies reviewed ....... 158 Appendix B.1 – Interview Script ........................................................................... 160 Appendix B.2 – Synergies with urban forestry policy implementation identified by participants, classified by process or outcomes ................................................... 163 Appendix B.3 – Trade-offs with urban forestry policy implementation identified by participants, classified by process or outcomes ................................................... 165 xi Appendix C.1 – Key assumptions on tree mortality rate, species mix, tree size and tree spacing for the moderate-effort interventions and the ambitious-effort interventions in 2050 ............................................................................................ 167 xii List of Tables Table 2.1 Population, land area, population density of cities reviewed under this study ............17 Table 2.2 Level of alignment between climate change and urban forest policies within each city .................................................................................................................................................29 Table 3.1 Definitions of key nodes in the interview transcript coding process ............................43 Table 3.2 Overview of the identified synergies and trade-offs among climate policies, urban planning policies, and urban forestry policies, and their implementation processes and outcomes. .................................................................................................................................45 Table 4.1 Plausible policy interventions in the areas of redevelopment (private jurisdiction) and infrastructure (public jurisdiction) ...............................................................................................77 Table 4.2 Summary of indicators to measure for each policy intervention .................................79 Table 4.3 Summary of the projected effects on urban forest attributes and livability co-benefits of selected policy interventions .....................................................................................................83 Table 4.4 Summary of the urban forest and livability co-benefit indicators of the redeveloped parcels in the baseline (2020) and after compliance with current tree planting requirements (2050) .......................................................................................................................................86 Table 4.5 Summary of the urban forest and livability indicators of the private parcels with no redevelopment in the baseline (2020) and after applying varied planting requirements (2050). .90 Table 4.6 Summary of the urban forest and livability indicators of all street segments in the baseline (2020) and after applying varied planting rates (2050) ................................................92 Table 4.7 Summary of the urban forest and livability co-benefit indicators of the selected 49 street segments in the baseline (2020), after planting street trees at 1.5x historical rate (2050), and after creating a blue-green street network (2050) ...............................................................96 Table 4.8 Summary of the urban forest and livability co-benefit indicators of the areas selected for a new park in the baseline (2020), after complying with current requirements on the number of trees per site (2050), and after creating a new neighbourhood park (2050) ......................... 100 Table 4.9 Summary of the measured urban forest and livability outcomes of the selected park in the baseline (2020) and applying varied park designs (2050) .................................................. 104 Table 4.10 Tree canopy results of implementing the selected urban forestry policy interventions and their contribution to achieving the 30% tree canopy target in the sandbox area ............... 107 xiii List of Figures Figure 1.1 Connections among the three focus areas in the dissertation: climate change, cities (densification), and urban forests ............................................................. 3 Figure 2.1 Projected climate change impacts identified from climate change policies .. 20 Figure 2.2 Current and target tree canopy percentages per city ................................... 22 Figure 2.3 Role(s) of urban forests for climate change mitigation and adaptation identified in the climate change policies ........................................................................ 23 Figure 2.4 Climate change impacts on urban forests identified in the climate change and urban forestry policies ................................................................................................... 24 Figure 2.5 Urban forest-related actions in climate change policies and climate change-related actions in urban forestry policies ....................................................................... 25 Figure 2.6 Role(s) of urban forests for climate change mitigation and adaptation identified in the urban forestry policies .......................................................................... 26 Figure 2.7 Types of actors that developed and implemented the climate change and urban forestry policies ................................................................................................... 31 Figure 3.1 Tree canopy cover by block within the Urban Containment Boundary ......... 40 Figure 3.2 Conceptual relationships of key nodes being coded .................................... 44 Figure 3.3 Relationships between synergies and their contributing factors ................... 49 Figure 3.4 Relationships between trade-offs and their contributing factors ................... 54 Figure 3.5 Connections between solutions and the contributing factors of trade-offs ... 56 Figure 4.1 Map of the real neighbourhood, its location in Vancouver, Canada, and the sandbox model for the baseline 2020............................................................................ 71 Figure 4.2 Illustration of the semi-automatic workflow of “aging out” and “planting” trees in the 2050 sandbox models ......................................................................................... 73 Figure 4.3 Selected policy interventions for analysis in areas of redevelopment and green infrastructure ....................................................................................................... 75 Figure 4.4 Maps of the locations and scales of where the policy interventions are applied ........................................................................................................................... 76 Figure 4.5 Cross section of a potential blue-green street design with 4 rows of street trees .............................................................................................................................. 78 xiv Figure 4.6 Private trees on redeveloped parcels in 2020 (the baseline) and in 2050 where current tree planting requirements are implemented .......................................... 85 Figure 4.7 Private trees on parcels with no redevelopment in the baseline (2020), with a moderate-effort intervention to ensure 80% of private parcels have at least 1 tree in 2050, and with an ambitious-effort intervention where 99% of private parcels have at least 2 trees on site in 2050 .......................................................................................... 88 Figure 4.8 Street trees in the baseline (2020), after applying the moderate-effort intervention with a 1.5x historical planting rate in 2050, and after applying the ambitious-effort intervention with a 3x historical rate of planting street trees in 2050 .................... 91 Figure 4.9 Location of highly treed streets and parcels within 400m of these highly treed streets in the baseline (2020), with a 1.5x historical street tree planting rate (2050), and with a 3x historical street tree planting rate (2050) ........................................................ 94 Figure 4.10 Street trees on the selected 49 street segments in the baseline (2020), with the moderate-effort intervention to plant street trees at 1.5x historical rate (2050) and with the ambitious-effort intervention to create a blue-green street network (2050). ..... 95 Figure 4.11 Location of highly treed blue-green streets and parcels within 400m of these highly treed streets in the baseline (2020), with a 1.5x historical street tree planting rate (2050), and with a blue-green street policy (2050). ....................................................... 98 Figure 4.12 Maps of the commercial area selected for a new neighbourhood park and the land use details of parcels surrounding the selected area in the baseline (2020), after complying with the current planting requirements (2050), and after creating a new neighbourhood park (2050). .......................................................................................... 99 Figure 4.13 Location of parks, park trees, and parcels within 400m of parks in the baseline (2020), after the current planting requirements are enforced (2050), and after creating a new neighbourhood park (2050). ................................................................ 102 Figure 4.14 The selected park in the baseline (2020), with the moderate-effort intervention that plants 2 rows of trees along park boundary (2050) and with the ambitious-effort intervention that plants groves of trees (2050). .................................. 103 Figure 4.15 Tree canopy cover and locations after applying all the moderate- and ambitious-effort interventions. ..................................................................................... 105 xv Figure 4.16 Absolute and standardized percentage of contribution each policy intervention made to achieving the 30% tree canopy target within the sandbox ......... 107 Figure 4.17 An urban forest system comprised of park trees (hubs), street trees (links), and private trees (sites) based on landscape ecology theory ...................................... 112 Figure 5.1 A framework for key stages of policy making and implementation and underlying critical factors for successful policy implementation, based on research findings of this dissertation .......................................................................................... 124 Figure 5.2 Recommendations for effective urban forest policy making and implementation based on research findings from this dissertation. ............................. 126 xvi List of Abbreviations EEBE Energy Efficiency in the Built Environment FAR Floor Area Ratio GHG Greenhouse Gas UGUD Urban Greening and Urban Densification VMT Vehicle Mileage Traveled xvii Glossary Blue-green street network A system of connected streets and associated grey infrastructure (e.g., drainage system) combined with green infrastructure (e.g., trees and bioswales) designed to reduce stormwater runoff and manage flood risk, and provide other ecosystem services (e.g., heat mitigation and air quality improvement) (City of Vancouver, n.d.-b). Climate change mitigation Actions to reduce or prevent the emission of GHG, the main cause of climate change. Climate change adaptation Actions to prevent or reduce the negative impacts of climate change, as well as to enhance the capacity to cope with emerging climate change impacts. Compact city “A spatial form characterized by ‘compactness’” with “dense and proximate development patterns, … [linked] transport systems, and accessibility to local services and jobs” (OECD, 2012, p. 26). Contributing factor of synergy or trade-off Factors (phenomena, events, projected trends etc.) that contribute to the occurrence of synergies or trade-offs. Floor area ratio A measure of the building floor space compared to the total land area. It is used to determine the maximum amount of building floor space allowed on a given piece of land. Green infrastructure a bioengineered system comprised of vegetation, soil, and drainage primarily for stormwater management purposes (Metro Vancouver, n.d.). Synergy A combined effect as a result of cooperation of two features, processes, or policies that is larger than the sum of the effects of individual policy/feature/process (Lexico.com, n.d.-a). Trade-off Conflicts or compromises between two policies, or between two desirable processes or outcomes during or after the implementation of policies (Lexico.com, n.d.-b). Urban forest Trees and associated vegetation in urban areas (Ferrini et al., 2017). Urban forestry Planning and management of urban forests – all trees and associated vegetation in urban areas (Ferrini et al., 2017). xviii Acknowledgements I am deeply grateful to many people who have offered me support and guidance during my PhD journey. First and foremost, I would like to express my deepest gratitude to my research committee members for their unwavering guidance, patience and support. I thank Dr. Stephen Sheppard for his kind heart, immense knowledge, and continuous mentorship. He has always offered insightful remarks and reminded me of the big picture. I am deeply indebted to Dr. Lorien Nesbitt for being such an approachable, encouraging and insightful supervisor. She was there for me whenever I needed her advice and support. I am also very thankful for the two wonderful committee members of mine, Professor Cynthia Girling and Dr. Cecil Konijnendijk. I thank Professor Girling for her sharp comments, fresh perspectives, and extended research and funding support. It is beyond what I could ever ask for. I have learned and benefited tremendously from working with Dr. Konijnendijk, a true leader in the field of urban forestry. I would not have started the PhD journey and been where I am today without his guidance and support. I received funding from the Social Sciences and Humanities Research Council of Canada (SSHRC) and the University of British Columbia (UBC). Their funding support for my work is greatly appreciated. I would also like to thank all the professionals who shared their insights and experience with me for my work described in Chapter 3. This piece of work would not be possible without their generous contribution. I would like to thank my friends and colleagues from the Urban Natures Lab, CALP, ElementsLab, and the Bachelor of Urban Forestry team for their encouragement and support. I am grateful to my PhTree friends, Sophie Nitoslawski and Corey Bassett, for the stimulating discussions and intense Zoom work sessions, for their critical reviews and career mentoring, and for all the fun we have had in the past 4.5 years. My PhD journey would not be the same without them. I would also like to thank Dr. Susan Day for being a caring, thoughtful, and supportive supervisor for my work besides my PhD. Thanks to her support, I was able to balance my research work and administrative xix duties. I also thank Dr. Yuhao Lu and Agatha Czekajlo for sharing their work, answering my random questions and always including me in the work they do. There are many other people who have offered encouragement and help during my PhD journey – Dr. Sara Barron, Deepti Mathew Iype, Dr. Tahia Devisscher, Dr. Angela Rout, Cheryl Ng, Leila Todd, Johanna Bock, Kaitlyn Pike, Kanchi Dave, Jessica Quinton, Dan Sax, and many more… I truly enjoyed our conversations and learnt a lot from each of you. Last but not least, special thanks are reserved for my family – my husband Qingfei Yang, my mother Baojiao Ye, and my dad Shuping Cheng – for their unconditional love and faith in me, and for their constant support and encouragement. I would not be able to achieve what I have without them. 1 Chapter 1: Introduction Cities are at the frontline of climate change mitigation and adaptation (Rosenzweig et al., 2010; Stevens & Senbel, 2017). On the one hand, cities are the major greenhouse gas (GHG) emitters, responsible for possibly 75% of global CO2 emissions from anthropogenic sources (Bulkeley, 2010; Grimm et al., 2008). On the other hand, cities, with a high concentration of people and infrastructure, are particularly vulnerable to climate change impacts, such as sea-level rise, extreme heat and flooding (Hobbie & Grimm, 2020). Currently, over half of the global population lives in urban areas (The World Bank, 2022). By 2050, the percentage of the world’s population living in cities is projected to further increase to 68% (United Nations, 2019). The increasing urbanization process globally is both a huge social-economic-environmental challenge and an excellent opportunity for novel, effective and efficient approaches to climate change mitigation and adaptation (Hobbie & Grimm, 2020; Rosenzweig et al., 2010). Cities also present major opportunities for climate change mitigation and adaptation, due to the city government’s capacity to control land use, development decisions, and some of the most carbon-intensive sectors such as buildings and transportation (Stevens & Senbel, 2017). To tackle the climate crisis, many cities have introduced various climate measures to reduce their GHG emissions (mitigation) as well as to enhance their capacity to cope with climate change impacts (adaptation) (Rosenzweig et al., 2010). Many of the current climate measures that cities adopt are heavily focused on mitigation (i.e., reduction of GHG emissions) from carbon-intensive sectors such as energy, buildings, land use and transportation (Bulkeley, 2010; Hamin & Gurran, 2009). Urban forests, comprised of tree-dominated vegetation in urban areas (Escobedo et al., 2011; Ferrini et al., 2017), are increasingly recognized as a nature-based approach to help address climate change and livability issues (Doick, 2022; McPherson et al., 1997; Ordóñez & Duinker, 2014; The White House, 2022). Increasing research in recent years has shown that urban forests provide environmental, social, and economic benefits that 2 directly address various climate change causes and impacts (Livesley et al., 2016; McPherson et al., 2011). Urban forests sequester carbon, manage stormwater, mitigate urban heat, and regulate microclimates (thereby lowering cooling energy use). Many social, cultural, and health benefits provided by urban forests, such as reducing fatigue and stress, enhancing social cohesion, increasing walkability and encouraging physical activities, directly contribute to the livability of a city (Nesbitt et al., 2017; Säumel et al., 2016). However, evidence has suggested that the integration of urban forests into cities’ climate action may lead to unintentional conflicts and trade-offs with other existing climate measures. For example, urban forests are found to be adversely impacted by the process of densification (i.e., building a compact city), which is a common urban development approach that cities adopt to reduce reliance on cars and cut Vehicle Miles Traveled (VMT) (Clark et al., 2020; Haaland & Konijnendijk van den Bosch, 2015; Hamin & Gurran, 2009). Trees in a dense urban environment face numerous challenges, such as intense space competition with other infrastructure like roads and utilities, compacted and poor-quality soils due to heavy traffic, and insufficient water due to a highly impervious environment (Diamond Head Consulting Ltd., 2017; Jim, 2017). Densification, especially the process of (re)developing into multi-dwelling units and building larger building footprints, is believed to be one of the main culprits for the loss of urban trees (Clark et al., 2020). In addition, increasing research has called attention to the impacts of climate change on urban forests, such as more frequent and intense extreme events, including heat waves, storms and droughts (Ordóñez & Duinker, 2014). These impacts will compound the adverse impacts of urbanization, imposing greater risks on urban forests. Despite the recent efforts to integrate urban forests into cities’ climate action, it is still unclear how local governments and their policies effectively consider and use the linkages and alignments between urban forest planning and management and climate action. Current research on the linkage between climate change and urban forests often focuses on the climate-related benefits of urban forests as well as the vulnerability of 3 urban forests to climate change. There is very limited research on how the connections between urban forests and climate change are effectively considered in current municipal policies, and the potential interactions, especially trade-offs, among municipal policies related to climate action and urban forestry. Climate change, cities (especially the densification trend and process), and urban forests are three complex but interconnected topics that are essential to the research work presented in this dissertation. Figure 1.1 illustrates the primary connections among these three topics. They provide the theoretical foundation for the research work covered in this dissertation. Figure 1.1 Connections among the three focus areas in the dissertation: climate change, cities (densification), and urban forests This figure has been designed using images from Flaticon.com. 4 1.1 Literature background This section focuses on the threats and opportunities in cities arising as urban areas densify and climate change intensifies, as well as the opportunities in urban forestry given the roles that urban forests play in helping cities tackle climate crises and become more livable. The section reviews three interrelated subject areas (Figure 1.1): 1.1.1 Climate change and cities: from threats to opportunities? 1.1.2 Climate change and urban forests: opportunities for climate solutions or challenges to tree survival? 1.1.3 Cities and urban forests: can a city be both dense and green? 1.1.1 Climate change and cities: from threats to opportunities? 1.1.1.1 Cities and causes and impacts of climate change (threats) Today, over half of the world’s population (4.4 billion people) lives in urban areas (The World Bank, 2022). It is no doubt that cities are one of the main drivers of increasing global GHG emissions, given the concentration of people and carbon-intensive activities in urban areas (Bai et al., 2018; Bulkeley, 2010). Cities account for about three-quarters of global emissions from energy use and other anthropogenic sources (Bai et al., 2018; Bulkeley, 2010). In an era of rapid urbanization, the percentage of urban population is projected to reach 68% by 2050, an increase of 2.5 billion people from 2018 (United Nations, 2019). The expansion of the urban population will require more production and consumption of energy, goods, and services (e.g., buildings, water, and waste disposal), leading to higher GHG emissions if proper mitigation strategies are not carefully implemented (Bulkeley, 2010; The World Bank, 2022). In addition to GHG emissions from carbon-intensive urban activities, such as construction, transport and energy use, cities may have substantial embodied emissions in the built infrastructure. These infrastructures, such as road networks, buildings, and transport systems, determine how efficiently energy is used, how people travel, and how buildings are cooled or heated, which can significantly influence cities’ emissions now and in the future (P. Erickson & Tempest, 2015). 5 On the other hand, cities, with a high concentration of population and infrastructure, are particularly vulnerable to climate change impacts. The major climate change impacts on urban dwellers include sea-level rise, increased and extreme temperatures, reduced precipitation (leading to water shortages), and more frequent and intense extreme weather events (e.g., heat waves, storms and droughts) (Hobbie & Grimm, 2020). Most major cities are located on low-elevation flood plains or coastal areas, susceptible to extreme rainfall events, sea-level rise and the consequences such as saltwater intrusion, flooding and storm surges (Bai et al., 2018; Hobbie & Grimm, 2020). For example, in 2017, severe floods in southeast Asian cities killed more than 1000 people and destroyed homes and services for 45 million people (Bai et al., 2018). In addition, the features of urban areas, such as prevalent paved, impervious surfaces and a high concentration of built infrastructure, can amplify some climate change impacts, such as flooding resulting from heavy storms and extreme heat due to increased temperatures and urban heat islands, putting urban dwellers at greater risks from climate change (Hobbie & Grimm, 2020). 1.1.1.2 Cities’ roles in climate change mitigation and adaptation (opportunities) Cities are at the core of the fight against climate change. As the centre of global wealth and innovation, cities also present vast opportunities for effective climate change solutions (Mi et al., 2019). The importance of city-level climate action is also reflected in cities’ capacity to govern some of the most emission-intensive sectors such as transport, land use, energy use, buildings and construction (Stevens & Senbel, 2017). Proper measures, if taken, can substantially enhance urban communities’ ability to both mitigate and adapt to climate change. For example, a simulation of a reduction of 1-2°C during extreme heat events through adaptive measures (e.g., an early warning system or the use of cooling devices) in the Greater London area could reduce annual heat-related mortality by 32-69% (Jenkins et al., 2014). Since the 1990s, an increasing number of cities have taken action to combat climate change (Sethi et al., 2020). Numerous actions have been implemented, such as 6 developing and switching to renewable energy, increasing densities of infrastructure and population, introducing disaster preparedness plans and stormwater management plans, and preserving green spaces and trees in the city (Hamin & Gurran, 2009; Mi et al., 2019). “Contemporary compact city approaches” (Burgess, 2002, p. 9), for example, have been increasingly endorsed and practised by many cities in order to lower their GHG emissions while accommodating an increasing urban population and achieving various environmental, social, and economic benefits. The compact city is “a spatial form characterized by “dense and proximate development patterns, … [linked] transport systems, and accessibility to local services and jobs” (OECD, 2012, p. 26). Compact cities can reduce personal vehicle usage and increase energy efficiency, thus decreasing transportation and energy-related emissions (Brittlebank & Clos, 2014; OECD, 2012). According to a study that compared two neighbourhoods with different levels of density in the State of California, USA, residents in the denser neighbourhood would drive 1172 fewer miles and consume 45 fewer gallons of fuel annually (Brown et al., 2008; Brownstone & Golob, 2009). The compact city form also allows lower-carbon transport and more efficient energy systems, such as light rails or district energy operations, since these systems can serve a higher population as density goes up. In addition, compact cities are practised for economic and social benefits, such as enhanced walkability and accessibility to day-to-day services, and the creation of a vibrant social space, which have proven to be increasingly important during the recent global pandemic (Brittlebank & Clos, 2014; Williams et al., 2010). Many cities are willing and able to take climate action (Rosenzweig et al., 2010). However, there is a concern that cities are not able to act fast and effectively enough to cope with increasingly emerging climate crises. For example, it is uncertain if Canadian cities are on track to meeting their climate GHG targets, as it highly depends on political will, multi-sectoral collaborations, innovation, and financial and other incentives, while being warmed at a double speed of the global average (Climate Action Tracker, 2022; Herbert et al., 2022). Some studies have pointed out the underlying conflicts between 7 cities’ mitigation and adaptation actions (e.g., urban containment for higher density may lead to a reduced permeable surface for adaptation actions such as natural infiltration to manage stormwater), which can significantly hinder the implementation of climate policies and their outcomes (Hamin & Gurran, 2009; Newell et al., 2018). Cities need more science-based research and information on the complex connections among various climate-focused policies and measures at the municipal level to support strategic long-range policy planning and implementation. 1.1.2 Climate change and urban forests: opportunities for climate solutions or challenges to tree survival? 1.1.2.1 Urban forests’ roles in climate change mitigation and adaptation Increasing research has suggested that urban forests can play a crucial role in mitigating climate change. Urban forests can offset or reduce CO2 emissions mainly in three ways: 1) through photosynthesis, which extracts atmospheric CO2 and stores it in tree biomass, 2) via microclimate regulation (e.g., by evapotranspiration and providing shade) that reduces the energy used for heating and cooling buildings, and 3) through storing organic carbon in soil (Escobedo et al., 2010; Nowak & Crane, 2002). Many studies have investigated the capacity of urban forests to sequester carbon (e.g., Z. G. Davies et al., 2011; Escobedo et al., 2010; McPherson et al., 1997, 2015; Nowak & Crane, 2002). The results vary according to a wide range of factors, such as geographical locations, weather conditions, tree species compositions, tree health, and urban forest management practices (Escobedo et al., 2010; Nowak & Crane, 2002). While many scholars agree that urban forests’ capacity to sequester atmospheric CO2 is somewhat moderate (e.g., offsetting <1% of the city’s GHG emissions) (Brack, 2002; Liu & Li, 2012), some believe that urban forests are a cost-effective approach to cope with climate change and sustainability issues, considering other non-climate-related benefits that urban forests provide (Baró et al., 2017; Escobedo et al., 2010; McPherson et al., 1997). As for microclimate regulation, urban forests help buildings reduce their energy use by regulating the surrounding microclimate, thereby reducing the emissions caused 8 by building energy use. During hot seasons, urban forests cool air temperatures by transpiring water and providing shade on buildings and outdoor spaces. When it gets cold, evergreen trees block winds and reduce heating needs in buildings (Brack, 2002). Some studies estimate that the economic value of city-wide energy savings by urban forests can reach over US$1 million per year (Brack, 2002; Nowak et al., 2016). However, the results vary by factors such as geographical location, city size, urban morphology, tree species, urban forest structure and health conditions. Perhaps urban forests are increasingly recognized for their adaptive rather than their mitigative benefits (Cheng et al., 2021). Urban forests provide shade (Akbari et al., 2001; Orlandini et al., 2017), cool air temperature (Akbari et al., 2001; Orlandini et al., 2017), reduce surface runoff and risks of flooding (Kuehler et al., 2017; Stovin et al., 2008), and improve social cohesion, which has proven to be increasingly critical in responding to climate emergencies (Wolf, 2017). For example, clustered trees (e.g., park trees) create cool islands (as opposed to urban heat islands) for urban dwellers that are up to 6°C cooler during extremely hot days (Orlandini et al., 2017). This is particularly important for groups who do not have easy access to other cooling devices or approaches. As more extreme weather events are projected to occur, such as extreme heat and heavy rainfalls, urban forests play an increasingly important role in helping urban communities cope with these extreme events and associated health risks. However, it should be noted that urban forests may impose risks to communities, such as increased fire and windthrow risks, due to the impacts of climate change. 1.1.2.2 Climate change impacts on urban forests Despite the various climate-related benefits that urban forests deliver, climate change can severely impact urban forest health (Ordóñez & Duinker, 2014). Although it is difficult to obtain an accurate projection of future microclimate changes due to climate change, it is generally agreed that cities will experience more variation in temperatures and become more polluted and more prone to droughts, flooding, and storm damage associated with extreme weather events (Ordóñez & Duinker, 2014; Stone, 2007). As a result, urban forests are expected to be increasingly stressed by these variations in 9 local weather (Brandt et al., 2016; Duinker et al., 2015). Urban forests are already stressed due to the unfavourable environment caused by heavy human and vehicular traffic, constrained growing space, compacted and non-native soil, and heavy air and water pollution (Haaland & Konijnendijk van den Bosch, 2015; Jim et al., 2018). These climate-change-induced changes in local climate will inevitably impose added stress on urban forests, leading to vulnerable and unhealthy urban forests that are prone to pests and other disturbances and even tree losses (Brandt et al., 2016). A study that investigated the level of vulnerability of urban forests to projected climate change impacts in Chicago found that 15% of the 120 studied species had moderate-high or high vulnerability to climate change, based on the projected climate change impacts, tree species hardiness zone, and adaptive capacity of tree species to extreme weather (Brandt et al., 2016). Another study has shed light on rare but damaging impacts on urban forests, such as freezing rain and extreme wind events, which provide important references for proper urban forest planning and management (Duinker et al., 2015). However, literature and research on the impacts of climate change on urban forests and the implications for practices is still scarce. 1.1.3 Cities and urban forests: can a city be both compact and green? 1.1.3.1 Connection between urban forests and urban livability Besides the climate-related benefits described in section 1.1.2.1, urban forests are crucial in enhancing public health and well-being and overall urban livability (Wolf, 2017). First of all, urban forests alter the physical environment of cities, thereby reducing certain health risks for urban residents (Shanahan et al., 2015). For example, the cooling effects of urban forests reduce heat-related mortalities and illnesses (e.g., heat strokes and heat cramps) (Hajat & Kosatky, 2010; Shanahan et al., 2015). Urban forests can improve air quality through the uptake and interception of air pollutants (Nowak et al., 2018). It was estimated that urban forests in 86 Canadian cities could remove 16,500 tonnes of air pollution in 2010 alone, avoiding 30 related human deaths and 22,000 acute respiratory incidents (Nowak et al., 2018). 10 In addition to the direct health benefits from the biophysical functions of urban forests, exposure to urban forests and other urban vegetation can trigger positive physiological and affective reactions and promote better physical and mental health (Shanahan et al., 2015; van den Bosch, 2017). Simply viewing or physically being in a more natural environment (e.g., an urban forest) can alleviate mental fatigue and stress (de Vries et al., 2013; Hartig et al., 2003; van den Bosch, 2017), accelerate recovery from an illness (Ulrich, 1984), and reduce mental disorder symptoms (Bratman et al., 2015; van den Berg et al., 2015). Urban forests can be beneficial in promoting more physical activity and a healthier lifestyle. People are more likely to exercise and are less likely to be obese if they live close to a safe and well-managed urban green space (C. Lee et al., 2013; van den Bosch, 2017). In addition, studies have shown urban nature’s role in creating and strengthening social ties in urban communities (Kuo, 2003; Wolf, 2017). Urban green spaces (e.g., urban forests) provide a common place for people to interact and recreate. The presence of trees, including the number and location of trees, is found to be correlated with the number and diversity of visitors and the length of their stays, and the social ties and safety within a neighbourhood (Kaźmierczak, 2013; Kuo, 2003). Close social ties also enhance a community’s capacity to adapt and recover from a severe climate event. 1.1.3.2 Impacts of urban densification on urban forests We are in an era of rapid urbanization and globalization. Urbanization processes involve drastic and large-scale land use and cover changes, leading to fragmented patches and habitats, highly impervious areas, polluted air and water, heightened heat island effects, and altered hydrologic cycles (Grimm et al., 2008). While many cities are striving for a higher density to reduce their GHG emissions and environmental impacts on surrounding ecosystems, there is an increasing concern over degradation and insufficient nature within the city (Haaland & Konijnendijk van den Bosch, 2015). In a dense or densifying urban area, urban forests are often threatened by fierce competition for space with other urban infrastructure (such as utility lines and buildings), limited nutrients and water due to compacted and poor soil, increased water and air pollution, variable and sometimes extreme weather, and constant construction and development 11 (Duinker et al., 2015; Jim et al., 2018; Koeser et al., 2013; Steenberg et al., 2017). As a result, urban trees tend not to grow to their full sizes (Quigley, 2004), have higher mortality (Koeser et al., 2013; Nowak et al., 1990), and are more prone to pests and diseases (Foran et al., 2015), compared to trees in rural and more “natural” settings. Many rapidly developing and/or densifying cities suffer from declining urban forests, such as Hong Kong (Jim, 2005), Merseyside (Pauleit et al., 2005), and Como (Brunner & Cozens, 2013). There is increasing interest among cities in exploring greening opportunities in the dense urban core for a wide range of climate and livability benefits (Brunner & Cozens, 2013; Haaland & Konijnendijk van den Bosch, 2015; Jim, 2017). Many cities have developed urban forest management plans to guide proper urban forestry practices (Ordóñez & Duinker, 2013) and introduced ambitious tree planting goals (e.g., the Million Tree Program in New York, Los Angeles and Chicago) (Pincetl et al., 2013). There is also a growing body of research exploring strategies for cities to become both dense and green (Barron, 2018; Haaland & Konijnendijk van den Bosch, 2015; Jim, 2017). Regardless, urban forests are still rarely prioritized or even discussed in urban planning for sustainable development (Brunner & Cozens, 2013; Guo et al., 2019; Haaland & Konijnendijk van den Bosch, 2015). Often, urbanization policies for higher density do not support or even work against urban forest development (Haaland & Konijnendijk van den Bosch, 2015; Shaw et al., 2014). Therefore, more research is needed to understand the relationships between densification and urban forests, and to explore opportunities to integrate urban forests and urban density for climate reliance and livability outcomes. 1.2 Research questions and dissertation overview Despite the increasing recognition of urban forests in enhancing climate resilience and urban livability, urban forest planning and management are often separated from climate action planning and urban planning processes (Brunner & Cozens, 2013). The overarching goal of this dissertation is to explore plausible and effective approaches for cities to avoid or minimize inherent trade-offs and conflicts among urban forestry, urban 12 planning, and climate action planning in order to better integrate urban forests into these mentioned processes and relevant policies (e.g., regional growth strategies and climate action plans). In order to fulfill this research goal, I first conducted an analysis of current municipal policies to understand how urban forests are considered and integrated into climate change policies and processes. For Chapter 2, I analyze the alignment of climate change and urban forestry policies in the 20 largest Canadian cities via a review of these cities’ climate change and urban forestry policies. Specifically, three research questions are addressed in this chapter: ● To what extent are urban forests considered and integrated in climate change governance and policies? ● To what extent is climate change considered and integrated in urban forestry policies? ● Are urban forestry policies and climate change policies well integrated, and where is the potential for better integration of urban forests in climate change policies? In Chapter 3, I delve further into the potential interactions among various municipal policies, implementation and outcomes related to urban forestry, climate action and climate-focused urban planning through a series of semi-structured interviews with experts in Metro Vancouver, Canada, a region densifying for a growing population and climate change mitigation. The specific research questions addressed in this chapter are: ● What are potential trade-offs and synergies among policies related to climate action, including climate-focused urban planning, and urban forestry? ● What are the potential solutions (i.e. policies, programs, or initiatives) for dense or densifying cities to resolve or avoid trade-offs among the aforementioned policies? 13 Building on the findings from Chapters 2 and 3, as well as the previously constructed “what-if” urban forest scenarios developed by the Urban Greening and Urban Densification (UGUD) Project (Czekajlo et al., minor revisions; ElementsLab, n.d.), in Chapter 4 I explore a range of plausible urban forestry policy interventions and assess their potential outcomes in 2050 via modelling a case study neighbourhood in Vancouver (within Metro Vancouver), Canada. The specific research questions discussed and answered in this chapter are: ● What plausible urban forestry policy interventions in the areas of redevelopment and infrastructure can cities implement to better sustain their urban forests despite densification and climate change? ● What are the projected outcomes of implementing the selected urban forestry policy interventions by the year 2050? In the final chapter, Chapter 5, I synthesize the key research findings and provide possible directions for future research. 14 Chapter 2: Alignment of municipal climate change and urban forestry policies: A Canadian perspective 2.1 Introduction As discussed in Chapter 1, cities worldwide face tremendous pressure to address accelerated climate change. Urban forests, as multifunctional green infrastructure, are uniquely placed to provide various climate co-benefits to urban dwellers. Meanwhile, urban forests are also vulnerable to a wide range of issues that have emerged due to a changing climate (Brandt et al., 2016; Ordóñez & Duinker, 2014) and during the urbanization process (Endreny, 2018; Grimm et al., 2008; Haaland & Konijnendijk van den Bosch, 2015) (see 1.1.2.2 and 1.1.3.2 in Chapter 1). As a result, urban forests in many cities around the world are fragmented and vulnerable, especially in rapidly developing countries and in densifying urban areas (Haaland & Konijnendijk van den Bosch, 2015; Steenberg et al., 2018). Despite disciplinary linkages between urban forests and climate change (e.g., climate change impacts on urban forests and urban forests’ roles in climate solutions), it is not clear whether governance frameworks and policies are effectively considering potential alignment between planning and management of urban forests and climate action. Indeed, scholars have called for attention to the lack of long-term and holistic visions for the role of urban forests in climate action (Brandt et al., 2016; Ferrini et al., 2017). Some research has examined intersections in the literature between urban forest management and climate change adaptation (Ordóñez, 2015), however there still seems to be a lack of information regarding the alignment and integration of relevant municipal policies. More research is needed to assess and bridge this particular gap. This study assesses the extent to which urban forests and climate change share the discursive space in local government policies in Canada, in order to provide references of gaps and opportunities for better alignment of policies and implementations in cities within and outside of Canada. Specifically, we posed the following questions: 1) To what 15 extent are urban forests considered and integrated in climate change governance and policies? 2) To what extent is climate change considered and integrated in urban forestry policies? 3) Are urban forestry policies and climate change policies well integrated, and where is the potential for better integration of urban forests in climate change policies? Based on our results, this study also aims to provide wide-reaching recommendations for locales interested in effectively integrating urban forests and other green infrastructure in climate change policy and planning. 2.1.1 Climate change and urban forests in the Canadian context The Canadian context provides substantial fodder for discussion at the intersection of climate change and urban forests. The term “urban forestry,” broadly defined as the planning and management of all tree dominated vegetation in urban areas (Ferrini et al., 2017), was coined at the University of Toronto in the 1960s, and forested landscapes have played important social, economic, and cultural roles throughout Canadian history. Today, the vast majority of Canadians interact with trees and forests in urban areas (Sinclair et al., 2014), including in residential yards (Conway, 2016), urban parks (Millward & Sabir, 2011), treed streetscapes, and institutional and commercial urban green spaces such as golf courses (Doll & Duinker, 2020) and cemeteries (Quinton et al., 2019). Trees in Canadian cities in particular offer various ecological, social, cultural and economic values, such as improving urban microclimate, enhancing social cohesion, supporting physical and mental health, and promoting tourism and community economic development (Nesbitt et al., 2017; Peckham et al., 2013) (see 1.1.2.1 and 1.1.3.1 in Chapter 1 for more examples). Canadian cities, located in geographically and climatically diverse regions across the country’s vast landscape, will consistently experience the varied effects of climate change, which include sea-level rise in coastal regions, flooding, wildland fires, heat waves and drought, and other extreme weather events, putting critical infrastructure and human well-being at risk (Bush & Lemmen, 2019). There is also an increasing recognition of the role of urban forests in coping with climate change, driving a growing number of urban forestry policies in the past decade in Canada (Ordóñez & Duinker, 16 2013). Many Canadian cities continue to experience a series of urban forest challenges, such as widespread canopy losses and monoculture planting, along with increasing pressures from growing populations and effects associated with climate change (Ordóñez & Duinker, 2013; Tree Canada, 2019). The governance systems involved in climate change action and urban forest management will invariably influence how urban forests respond to the impacts of climate change, as well as shape nature-based mitigation and adaptation strategies. In Canada, climate change policies are usually developed at the municipal, provincial, and federal levels, with varying degrees of implementation and enforcement and a wide range of climate-related actions by region (Bauer & Steurer, 2014). Most provinces, such as British Columbia and Ontario, require climate change to be included in municipal official plans. Nova Scotia is the only province that mandates municipalities to create stand-alone climate change plans (Guyadeen et al., 2019). The Pan-Canadian Framework on Clean Growth and Climate Change (2016), a national climate change mitigation and adaptation strategy, has explicitly recognized the importance of local and municipal bodies in developing local climate solutions, providing opportunities for urban forests to play significant roles in climate change mitigation and adaptation. Urban forest management decisions, on the other hand, take place almost exclusively at the municipal level, with minimal cohesive vision and policies enacted at federal and provincial level where forests appear to be seen as exclusively exurban. The Canadian Urban Forest Strategy (Tree Canada, 2019), an initiative led by a national non-profit charity Tree Canada, was developed in 2019 to address this gap, presenting a sustained long-term vision and support for urban forest management at the national level. Nonetheless, the strategic planning and day-to-day management decisions are still made mostly by the municipal urban foresters (Ordóñez et al., 2020). Identifying opportunities for cohesion in policy making, particularly at the local level, could pave the way towards maximizing co-benefits created from strategic urban forest planning and climate change mitigation and adaptation strategies. 17 2.2 Methods The main goal of this study was to explore whether and to what extent urban forestry policies and climate change policies are mutually supportive and reinforcing. To this end, Canadian policy documents publicly available from the municipal websites in digital form were identified and reviewed (see Appendix A.1 for a full list of policies and their source links). These included urban forest-related management plans and policies, and climate change plans articulated at the municipal level. Policies published by June 30, 2020 in both English and French, the two official languages of Canada, were analyzed. For scoping purposes, the 20 largest Canadian cities based on population were chosen, representing approximately 40% of all people living in Canada and just under half of all urban dwellers (Table 2.1). Larger cities are more likely to have developed both climate change and urban forest strategies, allowing for a comparative analysis of mutual links and considerations. Table 2.1 Population, land area, population density of cities reviewed under this study Municipality Province Population* Land Area* (km2, 2016) Population Density (/km2) Climate Change Policy Urban Forestry Policy Toronto Ontario 2,731,571 630 4335 Y Y Montréal Québec 1,704,694 366 4662 Y Y (Vision) Calgary Alberta 1,239,220 826 1501 Y N Ottawa Ontario 934,243 2790 335 Y Y Edmonton Alberta 932,546 685 1361 Y Y Mississauga Ontario 721,599 292 2468 Y Y Winnipeg Manitoba 705,244 464 1519 Y UD Vancouver British Columbia 631,486 115 5493 Y Y Brampton Ontario 593,638 266 2229 N** N** Hamilton Ontario 536,917 1117 481 Y Y (Work Plan) Québec Québec 531,902 453 1173 UD** Y (Vision) Surrey British Columbia 517,887 316 1637 Y UD** Laval Québec 422,993 247 1711 Y Y Halifax Nova Scotia 403,131 5490 73 Y Y London Ontario 383,822 420 913 Y (only on energy) Y Markham Ontario 328,966 212 1549 N** N Vaughan Ontario 306,233 274 1119 Y (only on GHG reduction) Y 18 Municipality Province Population* Land Area* (km2, 2016) Population Density (/km2) Climate Change Policy Urban Forestry Policy Gatineau Québec 276,245 343 806 N Y Saskatoon Saskatchewan 246,376 228 1080 Y UD** Longueuil Québec 239,700 116 2071 Y (only on GHG reduction) Y • Where municipal climate change and/or urban forestry policies were not available, related policies (e.g. provincial climate change policy or environmental master plan, indicated by “**” below) were reviewed to retrieve relevant background information (e.g., climate change impacts, urban forest area and definition). See the full list of policies reviewed in Appendix A.1. • “Y” stands for yes, “N” stands for no, and “UD” stands for under development. • *Population and land area information retrieved from Statistics Canada (2019). • **Related policies instead of climate change or urban forestry policies were reviewed. We carried out a content analysis, with information extracted verbatim based on explicit mention of pre-determined keywords based on the aforementioned research questions. For each climate-related plan, we searched for “urban forest*”, “urban green*”, “tree*”, “planting”, “park”, and “garden*”. A similar methodology was undertaken for documents in French (e.g. “arbre”, “plantation”, “forêt urbaine”, and “verdissement”). For each urban forest-related plan, we searched for mentions of “climat*”, “climate change”, “mitigation”, “adaptation” (and similarly for documents in French, e.g. “climat*”, “changement(s) climatique(s)”, “atténuation”, and “adaptation”). Content related to urban forest proxy terms such as urban green spaces and green infrastructure were also included in the analysis. We then organized the extracted text into a database with pre-established high-level themes and categories in Microsoft Excel (Version 16.16.27). Having a system of themes and criterion was important for further analysis and comparison, as each policy might have different levels of details, and conceptualizations of climate change or urban forest-related information (Ordóñez & Duinker, 2013). Four high-level themes were developed based on the research questions, including 1) setting and overview, 2) urban forest-related content in climate change policies, 3) climate change-related content in 19 urban forestry policies, and 4) governance context of both types of policies. The text was organized into distinct codes/categories that were not pre-established but instead were developed as the analysis of extracted text proceeded. A frequency analysis of the categories (i.e., the number of occurrences) was conducted for each type of policy (climate change or urban forestry policy) for quantitative comparison purposes. Two types of actors were identified in the analysis: Actors involved in policy making (i.e. the main contributors that create the policy, information extracted from the author list and acknowledgement section) and actors involved in implementation (i.e. individuals or groups who carry out the proposed actions, identified through the action section of the policies where actors are assigned to each task/action). Both types of actors were then further categorized into government actors that are external or higher than municipal level, and government units at municipal level (including municipal departments, such as parks and recreation), civic society (e.g. non-government organizations, citizen groups, individual residents), businesses/business associations, and academia. 2.3 Results 2.3.1 Overview of the study cities Among the 20 cities reviewed, 18 (90%) have developed policies on climate change or urban forestry (Table 2.1). Sixteen have developed a climate change policy focusing on either climate change mitigation or adaptation, or both, and 14 (70%) have adopted urban forestry policies in one format or another, ranging from a broad vision document to a detailed management plan. Among the cities, 12 (60%) have developed both climate change and urban forestry policies. 2.3.1.1 Projected climate change impacts Projected climate change impacts are described in all 16 municipal climate change policies, two regional/provincial policies and one municipal sustainability plan. As 20 illustrated in Figure 2.1, the most recognized impact is warmer temperatures (identified in the policies of 17 out of 20 cities). Other commonly identified climate change impacts across the cities include more intense rainfalls/storms (by 11 cities), increased risk of flooding (11), altered ecosystem dynamics (10), increased risks of drought and other extreme weather events such as freezing rains and tornados (9), increased health concerns such as increased vector-borne diseases or heat stress (8). Climate change impacts on the urban infrastructure and systems such as financial systems and green/grey infrastructure were identified by 5 cities. The least common climate change impacts are often specific to locations (e.g., increased access to the northern region identified by the Province of Québec), and positive effects (e.g., increased tourism or reduced heating days, both by one policy only). Figure 2.1 Projected climate change impacts identified from climate change policies 2.3.1.2 Urban forest definition and condition Fourteen cities include a definition of urban forests in their climate change and/or urban forestry policies. Each city defines the urban forest differently, despite some 21 commonalities. Most cities include trees in natural or naturalized areas (14 cities), private trees (12), associated vegetation (9), and habitat/growing environment (9) as key components of their urban forests. Some cities consider urban forests as part of green infrastructure (7) and/or natural assets (3). Two cities acknowledge the cultural components of urban forests, and two cities acknowledge peri-urban forests. Urban tree canopy percentage (i.e. the percentage of total land area covered by tree canopy when viewed from above) is commonly used as a key indicator to measure current urban forest conditions and track progress towards established goals. Figure 2.2 indicates the percentage of tree canopy cover in terms of both current state and targets. Nineteen cities have assessed their current urban tree canopy (median: 20.5%, average: 22.1%) and 16 of them have set up urban tree canopy targets (median: 27.5%, average: 28.4%). Gatineau (45%) and Halifax (43%) are the only two cities currently with over 40% tree canopy cover, whereas Calgary has the lowest percentage (7.1%). Urban forest canopy percentage obviously varies by how cities define their municipal boundaries. Some cities include low-density suburbs while others only include urban areas. Halifax, for example, has the highest tree canopy cover as it includes suburban and peri-urban areas in the assessment. As for urban tree canopy targets, most (12) cities aim for an increase of less than 10% of tree canopy in the next 10 to 45 years, except four cities — Toronto (19.5%), Calgary (12.9%), Markham (12%), and Halifax (10%). Among the cities that proposed a specific timeframe for their urban tree canopy targets, the average tree canopy target per decade was calculated for across-city comparisons. A wide range of targets (average increase per decade) are proposed, ranging from 1.3% increase per decade (Vancouver) to 9.8% increase per decade (Toronto). Four cities have not set up an urban tree canopy target, including Gatineau boasting the highest current urban tree canopy cover. Saskatoon is the only city with no records of current urban tree canopy percentage or an urban tree canopy target. It should be also noted that most cities adopt different timelines and scopes for urban forest targets; extra caution should be taken when comparing the numbers. 22 Figure 2.2 Current and target tree canopy percentages per city *No current tree canopy information could be retrieved for the City of Saskatoon, which is therefore not displayed in the Figure. Thirteen cities’ policies have identified key challenges to their urban forests. Although climate change impacts are not the most commonly-identified challenge (7 cities), it is usually a driver of the most common ones, such as invasive species, pests and diseases (13 cities). Urbanization is another key challenge to urban forests. Specific urbanization-related challenges include development pressure (12), harsh growing conditions (9), limited space (8), conflicts with utilities and infrastructure (3), and population growth (1). 2.3.2 Climate change policies: references to urban forestry and greening The climate change policies of 15 cities (out of 16) mentioned or described urban forests or related terms, such as green space, green infrastructure, and natural areas/assets. Figure 2.3 illustrates the climate benefits of urban forests, as described in the municipal climate change policies of 13 cities. Ten cities mentioned the mitigative benefits of urban forests, such as carbon storage (6 cities) and energy savings (3). Fourteen cities mentioned adaptive benefits, such as temperature regulation via shading and cooling (8), and stormwater management and runoff mitigation (8). Enhancing food security (e.g. fruit trees and community gardens) and providing wind buffer) are the least recognized benefits, each by one city – Winnipeg and Surrey. 23 Calgary was the only city that mentioned the role of urban forests in meeting urban community’s everyday needs, e.g., by providing space to recreate and capacity to manage stormwater. Figure 2.3 Role(s) of urban forests for climate change mitigation and adaptation identified in the climate change policies The impacts of climate change on urban forests are recognized in climate change policies of 12 cities, though most are brief and high-level (Figure 2.4). Increased temperature is the most commonly identified impact (7 cities), followed by droughts (6, mostly in mid-Canada) and other extreme weather such as ice storms or hurricanes (6, all in eastern Canada). Altered weather patterns also introduce various identified stressors, such as increased risk of urban-wildland interface fires (3), reduced tree habitat (3) and increased invasive species, pests and diseases (5). A few cities mention secondary impacts such as increased maintenance costs due to jeopardized tree health 24 (4), and tree pollen and mould spore impacts on public health due to changing wind and weather patterns (by Halifax). Figure 2.4 Climate change impacts on urban forests identified in the climate change and urban forestry policies The climate change policies also propose actions related to urban forests (Figure 2.5). The most frequently mentioned is to strengthen engagement and collaboration with stakeholders (12 cities). Some examples of practices include developing and implementing community-based tree planting/care programs (such as London’s Tree Captains and Tree Teacher Program and Surrey's Natural Areas Partnership) and forming working groups to increase collaboration between stakeholders. The second most popular action (9) is to increase tree and other vegetation covers for various climate-related benefits, such as heat mitigation and stormwater management. Other actions are about better integration of climate change and urban forestry policy practices, such as considering climate change in urban forest planning and 25 management (6). Specific proposals to enhance urban forests’ health and resilience to climate change are included, such as restoring ecosystems for adaptation/resilience purposes (6), and monitoring and controlling pests and diseases (5). Figure 2.5 Urban forest-related actions in climate change policies and climate change-related actions in urban forestry policies 2.3.3 Urban forestry policies: references to climate change Climate change is mentioned in all 14 urban forestry policies, with ten describing the urban forest’s role in climate change mitigation and/or adaptation (Figure 2.6). The mitigative benefits include carbon sequestration and storage (by 8 cities) and energy savings (7). More adaptive benefits of urban forests are recognized, such as temperature regulation (the most recognized, by 10 cities) and stormwater management (7), which is similar to those identified in climate change policies. Water quality improvement is specifically mentioned by Toronto’s urban forestry policy, possibly due to its large ravines. Ottawa is the only city that mentioned the role of urban forests in 26 providing UV protection via tree shade, as well as the role of trees in building community resilience and stability through promoting social interaction. Only one of five cities in the province of Québec (Montréal) outlines the climatic benefits of urban forests. Figure 2.6 Role(s) of urban forests for climate change mitigation and adaptation identified in the urban forestry policies On the other hand, climate change-related impacts on urban forests are identified by municipal urban forestry policies of nine cities (Figure 2.4). The most commonly identified impacts (also aligned with those in climate change policies) include increased risk of drought (by 8 cities), increased temperature/heat waves (7), more invasive species, pests and diseases (6), and more frequent/intense extreme weather events (e.g. wind and ice storms) (6). Vancouver is the only city that identified the adverse impacts of climate change on growing conditions of established urban trees and 27 vegetation. Halifax is the only city that mentioned the impacts of unfavourable public perception towards trees due to climate change (i.e., considering trees as unwanted hazards in extreme weather events that damage their properties and impose risks to personal safety). Interestingly, Vancouver and Toronto identified positive impacts of climate change on urban forests — longer growing seasons due to warmer temperatures, and more optimal growing environments for certain urban species. Eleven urban forestry policies propose climate-related actions (Figure 2.5). The majority of actions aim to address climate change via expanding tree and vegetation cover and enhancing tree and forest resilience to climate change. Implementing or strengthening tree planting programs is the only identified action for increasing tree cover (also the most mentioned action, by 7 cities). Initiatives to enhance urban forest resilience include increasing tree diversity (7), testing/selecting/planting climate-resilient species (6), considering climate change impacts in management/planning process (4), controlling and monitoring invasive species (4), developing a comprehensive monitoring system such as native species mapping (2), and increasing green connectivity (1). These initiatives can have a supplementary effect on increasing urban forest cover. Several cities propose enhancing collaboration and alignment with other climate initiatives through developing new or updating existing urban forestry policies (e.g., bylaws, standards or regulations) (4) and increasing stakeholder collaboration via information sharing and cross-jurisdictional partnership (3). Four cities call for more research on climate change and urban forests on climate change impacts on urban forests, valuation of urban forest’s health and species selection to guide policy-making and implementation processes. It should be noted that some urban forestry policies include benefits such as promoting social well-being, and actions such as conducting comprehensive analyses on urban forest conditions, which are not identified/discussed in this section, because they do not associate such benefits or actions with climate change. 28 2.3.4 Alignment of policies: within-city comparison To better understand the alignment of climate change and urban forestry policies within each city, the extracted text from both types of policies was compared for each city (Table 2.2). Aside from eight cities that do not have a municipal policy on climate action or urban forestry (or both), most cities’ climate change and urban forestry policies do not address the same information relating to three perspectives in the content analysis above: climate change impacts on urban forests, the urban forest’s roles in climate change mitigation and adaptation, and urban forest-related or climate change-related action(s). Only three of the 12 cities (Mississauga, Vancouver, and Halifax) include some aligned information between both types of policies in all three perspectives. Mississauga is the only city where over two-thirds of extracted text aligns, though only for one of the three perspectives examined. In addition, 58% of the 12 cities have either introduced or updated their climate change policies after introducing an urban forestry policy, while 25% did the opposite. The different timing for adopting or updating the municipal policies might be a factor contributing to the misalignment of policies. Four categories of cities were identified based on the level of overlap between policies: 1) Cities that do not have their own climate change and/or urban forestry policy (8 cities: Calgary, Winnipeg, Brampton, Québec, Surrey, Markham, Gatineau, and Saskatoon). No comparison was conducted. 2) Cities with both types of policies but at least one of the policies does not address climate change or urban forests (Longueuil). Longueuil’s climate change policy does not discuss urban forests. 3) Cities with relevant information in both types of policies but most information does not match (8 cities: Toronto, Montreal, Ottawa, Edmonton, Hamilton, Laval, London, and Vaughan). For example, Laval’s urban forest-related actions in its climate change policy (e.g. tree planting for heat mitigation) are completely different from the climate change-related action in its urban forestry policy which focuses on diversifying species of its urban forests. 4) Cities that include relevant, and to some extent aligned, information in both types of policies (3 cities: Mississauga, Vancouver, and Halifax). 29 Table 2.2 Level of alignment between climate change (CC) and urban forest (UF) policies within each city Cells are colour-coded to indicate different levels of alignment (approx. level of similar topics and information covered). See the colour legend below. Level of Alignment N/A (No CC and/or UF policy) None (Nothing in common) Weak (less than1/3 aligned) Medium (1/3 to 2/3 aligned) Strong (More than 2/3 aligned) Color Label Municipality CC Impacts on UF UF Benefits in CC Mitigation / Adaptation UF-Related or CC-Related Action Toronto Montreal Calgary Ottawa Edmonton Mississauga Winnipeg Vancouver Brampton Hamilton Quebec Surrey Laval Halifax London Markham Vaughan Gatineau Saskatoon Longueuil 30 2.3.5 Governance context of climate change and urban forestry policies Municipal governments are the dominant actors in the development and implementation of both climate change and urban forestry policies, being involved in every municipal climate change and urban forestry policy (Figure 2.7). There is only one exception for urban forestry policies in Gatineau, developed by the National Capital Commission (a Canadian Crown corporation). In climate change policy-making processes, government units at the regional level or above (e.g. provincial or national), businesses (e.g. utility companies that support renewable energy), and civic societies (e.g. builders’ associations and climate champion grassroot organizations) also played a key role in the climate change arena, whereas academia (e.g. universities) was less involved in creating and implementing climate change policies (mainly as expert/research groups advising policy making and/or best practices). Unlike climate change policies, the majority of actors beyond municipal government are somewhat less involved in the development and implementation of urban forestry policies, with the exception of civic society. Civic societies were involved in slightly more urban forestry policy implementation (8 cities) than other actors (5), while the majority of responsibility and decision-making power still falls under the municipal government. 31 Figure 2.7 Types of actors that developed and implemented the climate change and urban forestry policies 2.4 Discussion 2.4.1 How are urban forests considered and integrated into climate change policies, and vice versa? Urban forests, along with other identified proxy terms such as urban green spaces and urban green infrastructure, are recognized in 15 out of 16 climate change policies as a way to mitigate climate change and to enhance urban resilience to adverse climate impacts. More adaptive benefits (9 by climate change policies and 7 by urban forestry policies) are identified than mitigative ones (2 by both types of policies), potentially indicating a stronger focus on climate adaptation for urban forest-based actions, especially on climate change induced environmental issues. Climate change, on the other hand, is mentioned by all 14 municipal urban forestry policies, mainly as a threat to urban forests due to various adverse climate impacts. Interestingly, Toronto and Vancouver identify positive impacts of climate change on urban forests and Mississauga indicates synergetic climate change and urban forest initiatives. The consideration of 32 climate change impacts also leads to the inclusion of specific actions addressing climate change in urban forestry policies, such as planting climate-resilient species. 2.4.2 Missed opportunities: policy gaps across and within cities? Despite the commonalities mentioned above, results revealed significant gaps and discrepancies between climate change policies and urban forestry policies, highlighting potential opportunities for improvements in policy planning and implementation. As of June 2020, eight out of the 20 largest Canadian cities have not developed a climate change policy or urban forestry policy: Brampton and Markham have neither at the municipal level; Gatineau and Québec have an urban forestry policy instead of a climate change policy; and Calgary, Winnipeg, Surrey and Saskatoon do not have their own urban forestry policies yet (Winnipeg, Surrey and Saskatoon are developing their urban forestry policies), although they refer to urban forests in their climate change policies. It is possible that these cities have other related policies to support the management of urban forests and other green spaces (e.g., City of Surrey has a shade tree management strategy and a natural areas management plan). However, the lack of climate change and/or urban forestry policies may be an indication of insufficient awareness, leadership, and/or capacity to appropriately address emerging climate change and urban forest issues. The lack of national and provincial level programs, especially in urban forestry, is another potential reason for the policy gap. The study identified significant discrepancies between climate change and urban forestry policies, indicating a poor alignment between climate change and urban forestry policies. For example, strengthening engagement and collaboration is the most identified urban forest-related action in climate change policies (by 12), while being one of the least identified climate change-related actions in urban forestry policies (by 3), indicating a potentially weaker emphasis on engagement and collaboration in urban forestry policies. It is however possible that engagement and collaboration are not associated with climate change in urban forestry policies therefore being excluded in this study. Some differences may be a result of regional disparities in terms of climate, geography, culture and demographics. However, the discrepancies between policies 33 within the same city are prevalent in the study sites. Even cities such as Halifax and Vancouver, with relatively more aligned policies, have mismatched information. For example, Halifax’s climate change policy mentions increased health concerns due to more dispersed allergy-causing pollen and mould spores, which is not mentioned in its urban forestry policy. Meanwhile, changing public perceptions of urban forests due to climate change impacts is mentioned in its urban forestry policy but not in its climate change policy. Such discrepancies suggest a significant gap in communication and collaboration between municipal departments (Larsen et al., 2012a; Ordóñez et al., 2020). It is crucial to address these silos for better collaboration and implementation, especially considering the fact that engagement/collaboration is the most identified urban forest-related action in climate change policies across study cities. It should be noted that over half of the study cities have introduced or updated their climate change policies after the development of their urban forestry policies, which could potentially contribute to the mismatch of information here. It highlights the need for municipal governments to review and update relevant policies to ensure alignment and avoid conflicts and confusion. Discrepancies are also reflected in the varying urban forest definitions and terms used in the policies. The different definitions and terms used among cities could be an indication of locally-specific understanding and contexts, particularly given the varied physical geographies, forest ecosystems, and climates represented in this study. These inconsistencies may also stem from the lack of a cohesive national urban forest vision and strategy, highlighting a lack of cross-scale collaboration between multiple levels of government. Some cities in this study use various terms other than urban forests in their climate change policies, such as urban green infrastructure and green space, in some cases without clear definitions, while having a separate urban forestry policy. Urban forest scholars have noted the importance of clear definitions and consistent language, to avoid potential confusion and misinterpretation in implementation and cross-sector/jurisdictional collaboration and to avoid the loss of emphasis on urban forests (Escobedo et al., 2019). 34 Another component that proved vague and inconsistent is consideration of engagement and/or collaboration in both climate change and urban forestry policies. Despite being the most cited urban forest-related action in climate change policies (by 12 cities), engagement and collaboration are defined with varying levels of detail in different cities, from just a mention in the entire policy to a dedicated section. The vagueness (and lack of policies) is possibly caused by a lack of information, hard-to-measure progress, and silos between departments and actors (Ordóñez & Duinker, 2013). Moreover, both climate change and urban forestry policies are developed and implemented primarily by municipal government units, indicating an uneven distribution of power (Ordóñez et al., 2020). Despite a trend of increasing participatory process in decision making, with vaguely defined engagement and collaboration approaches, actors/stakeholders other than municipal government may not be effectively engaged and their values may not be truly reflected in the policies and implementation (Sheppard et al., 2017). It is especially concerning for urban forestry policies, given that in most cities in Canada, a large portion of the urban forest is on private property (Conway, 2016). Fundamentally, urban forest management should be “a process that satisfies what urban citizens consider important” (Ordóñez, 2015, p. 217). The analysis indicates that most identified challenges to urban forests in the policies are driven by either climate change (e.g. increasing invasive species) and urbanization (e.g. limited space) (Ordóñez & Duinker, 2014; Tree Canada, 2019). Specifically, drought, though being one of the most recognized climate change impacts on urban forests in both types of policies, is only considered by half of the cities (9 out of 18) as a significant climate impact on cities in general. This potentially highlights the severe impacts of drought on urban forests, and the importance of efforts to ensure water availability in enhancing urban forest’s resilience to climate change impacts, especially in cities expecting warmer temperatures and less precipitation (May et al., 2013). Urbanization, on the other hand, threatens urban forest health and longevity by disrupting more naturalized habitat and restricting the amount of plantable spaces, leading to tree declines and removals at a rate that tree planting programs in many cities cannot keep up with. Urbanization is a more severe issue in cities with urban 35 growth boundaries or being geographically confined, such as Vancouver, BC and Toronto, ON Canada (Haaland & Konijnendijk van den Bosch, 2015). Cities need creative solutions to preserve existing urban forests and better integrate urban forest into urban planning process for more sustainable and climate-proof urbanization (Jim et al., 2018). Although the study is focused on Canadian cities, the challenges and opportunities identified here are not unique. Climate change is the universal challenge faced by cities worldwide, and many cities are now starting to incorporate urban forests or more broadly nature-based solutions into their agenda for sustainable development (Haaland & Konijnendijk van den Bosch, 2015; Hobbie & Grimm, 2020; Ordóñez & Duinker, 2014). The study provides useful and important references for other cities in Canada and beyond, especially cities that are currently developing and/or implementing policies for strategic planning and management of urban forests for climate resilience. Although cities around the world will no doubt experience the effects of climate change in varied ways, and will differ in terms of mitigation and adaptation capacity and strategies, key issues outlined above — such as vague calls for engagement and collaboration as well as inconsistent terminology across policies — apply to many locales. We encourage municipal researchers and practitioners alike to consider the potential connections and synergies between climate change and urban forestry policies, and more importantly the gaps and missed opportunities that might be omitted in the process of policy planning and implementation. 2.4.3 Limitations and future research Although this study attempted to be as comprehensive as possible, several limitations should be addressed by future research. Firstly, extraction and analysis of information required re-categorization and interpretation, which could potentially lead to bias due to researchers’ views and values. Although a comprehensive set of keywords was used in the analysis, it is possible that more keywords speaking to specific climate change impacts, such as droughts or fire, could have been searched and some relevant information was omitted. Moreover, the study only relied on publicly available policy 36 documents, which may omit some internal relevant research and policy information. Policy documents vary in their nature and scope; the policy review methodology may not be able to capture the full breadth of urban forest or climate change policy initiatives happening on the ground. Future research using alternative methodologies and expanding to more cities in Canada and beyond is needed to gain a more in-depth understanding of this topic. These Canadian-focused results should be compared with international contexts, and potentially identify policy solutions not yet in place in Canada, or vice versa. In addition, the study did not investigate land use policies which have significant impacts on urban forests and implementation of climate actions. Future research can look into land use policies and their connections with climate actions and urban forest-based actions to yield insightful results to support informed and comprehensive urban planning processes. The study also reaffirmed potential connections between urban forest-based actions and other climate actions, such as increasing urban tree cover and reducing energy demand. More research on these relationships (e.g. conflicts or synergies) will be helpful to improve the effectiveness of policy-making and implementation. 2.4.4 Implications for future research Key recommendations for climate change and urban forestry policy planning and implementation can be drawn from the analysis: 1) There is a strong need for a national (or at least provincial/regional) urban forest vision to guide urban forestry policy development at the municipal level; 2) Identifying alignment and/or discrepancies between climate change and urban forestry policies across and within cities is an important first step in assessing potential gaps and co-benefits, and informing stakeholder/actor analyses; 3) Municipalities should adopt consistent and clear language in related policies to avoid unnecessary confusion and misinterpretation. Terms or metaphors can be 37 used for different needs only if clear definitions and explanations for terminology usage are provided. 4) Engagement and collaboration processes should be further explicitly described in climate change and urban forestry policies to ensure that the values of stakeholders (especially local communities) are truly reflected in the policies. 5) Urban forests can be significantly impacted by climate change. Some cities have already seen tree loss due to e.g. heat and drought. Urban forest managers and climate/sustainability practitioners need to consider the interconnected relationships between climate change and urban forests, as well as potential conflicting effects with other climate actions related to land use change and development (e.g. increase density to build a compact city, at the potential expense of green space preservation). 6) Other countries beyond Canada that also lack a national-level urban forest vision, network, and/or funding mechanisms may benefit from international policies and programs, such as Tree Cities of the World (https://treecitiesoftheworld.org). International standards for urban tree care, along with clear guidance around aligning local-level policies, could pave the way for uniting cities facing similar challenges and promote knowledge mobilization and capacity building for building greener, more resilient, and livable cities. 38 Chapter 3: Density and the forest: can and do they co-exist in a city? 3.1 Introduction In recent years, urban forests are increasingly recognized as a nature-based solution to climate change issues in cities (Ferrini et al., 2017). Many cities have introduced urban forest specific policies (e.g. city-wide strategic plans or rule-based regulations) and in some cases integrated them with existing climate and sustainability policy frameworks (Cheng et al., 2021; Conway & Urbani, 2007; Ordóñez & Duinker, 2013). However, the integration of urban forestry into climate and planning policies may unintentionally conflict with other climate goals and actions. For example, densification (or “the compact city approach”), a common action in cities’ climate policies for walkability, energy efficiency, and various other environmental and social benefits, can adversely impact urban forests and green space (Burton, 2000; Haaland & Konijnendijk van den Bosch, 2015, p. 760). Increasing density has also been a goal of urban planning and management for non-climate-change-related benefits, such as addressing housing affordability and encouraging more efficient use of finite urban land resources (Haaland & Konijnendijk van den Bosch, 2015). Trees in dense areas face numerous challenges, such as compacted soil, confined root space, and generally intense competition for space (Jim, 2017). Increasing evidence indicates that highly dense areas tend to have less green space (including trees), and tree losses often happen during the densification process (Haaland & Konijnendijk van den Bosch, 2015; Jim et al., 2018). Policies interact with each other, either in supportive or constraining manners, which may lead to unforeseen or undesired results during and after implementation. This occurs particularly often in the integration of newer policies, such as climate policies and urban forestry policies (Urwin & Jordan, 2008). The direct or indirect interplay of policies can support or undermine the implementation process and outcomes of these policies (Smith, 1973; Urwin & Jordan, 2008). Previous climate policy studies have revealed a 39 number of trade-offs between climate policies and other values that are driven by local policies (Baynham & Stevens, 2014; Newell et al., 2018). However, there is still very little research that systematically maps these relationships (especially the potential trade-offs) among climate action, related urban planning, and urban forestry policies. As more cities introduce urban forestry policies and incorporate urban forests into their climate action and urban planning policies and actions, more studies are needed to understand their potential trade-offs and synergies to support more efficient policy planning, implementation, and outcomes, and to ensure that key benefits provided by urban forests as nature-based solutions are optimised (Cheng et al., 2021; Newell et al., 2018). This study aims to explore relationships among policies relating to climate action, climate-focused urban planning, and urban forestry, through a case study of municipalities in Metro Vancouver, British Columbia, Canada. By conducting a series of semi-structured expert interviews, the study addressed the following research questions: 1) What are potential trade-offs and synergies among policies related to climate action, including climate-focused urban planning, and urban forestry? 2) What are the potential solutions (i.e. policies, programs, or initiatives) for dense or densifying cities to resolve or alleviate trade-offs among the aforementioned policies? 3.2 Methods 3.2.1 Study area The study focused on municipalities within the Metro Vancouver region of British Columbia (BC), Canada. Metro Vancouver represents a high diversity of demographics, cultures, and urban forms. It is also one of the densest regions in Canada. Metro Vancouver currently accommodates 55% (2.5 million) of the population in BC. The population is expected to grow by one million people by 2050, which will require roughly 500,000 additional housing units and 500,000 additional jobs (Metro Vancouver, 2021; 40 Yumagulova & Vertinsky, 2017). Cities in Metro Vancouver have agreed to concentrate developments within an Urban Containment Boundary (UCB, Figure 3.1) for more efficient land use, improved transit networks, improved access to amenities and services, and reduced GHG emissions (Metro Vancouver, 2021). Consequently, it is experiencing increasing challenges in balancing density and urban forests (Metro Vancouver, 2019b). Several assessments have reported losses of trees and vegetation in Metro Vancouver over time, likely driven by urbanization and population growth. It is estimated that 240 ha of forests have been lost within the UCB and 1000 ha for the whole region from 2009 to 2014 (Metro Vancouver, 2019b). Figure 3.1 Tree canopy cover by block within the Urban Containment Boundary *The grey area indicates the boundary of the Metro Vancouver Region. 41 Metro Vancouver is expected to experience profound climate change impacts, such as hotter and drier summers, wetter and warmer winters, and more extreme weather events (Metro Vancouver, 2019a). For example, the unprecedented heat domes in the summer of 2021 led to record-breaking temperatures and more than 600 heat-related deaths during the worst week (June 25 to July 1, 2021) in the Province of British Columbia (British Columbia Coroners Service, 2022; Human Rights Watch, 2021). To help mitigate these climate impacts, in 2008, Metro Vancouver set a regional target to reach an 80% reduction of GHG emissions (compared to 2007 levels) by 2050. A series of policies and programs have been introduced to reach this target since then. The regional targets and policies have also encouraged municipalities within the region to adopt their own climate action plans (Metro Vancouver, 2019a). 3.2.2 Interviews and procedure To explore the relationships among climate action, urban planning, and urban forestry policies (particularly after the introduction and integration of urban forestry policies), a series of semi-structured interviews were conducted with experts who had the knowledge and experience working with urban forest or related policies. Inclusion criteria included all the following: 1) working in urban forestry or related fields (e.g., green infrastructure or green street planning), and having experience in urban planning, climate action planning and sustainability for over three years where possible; 2) working at or with the regional or municipal governments within the Metro Vancouver region; and 3) direct involvement in developing, implementing, or monitoring climate, urban planning, urban forestry, or related policies at the municipal level. A list of potential participants was developed, reviewed and approved by the research team prior to recruitment. Additional participants were identified through purposive snowball sampling (Palinkas et al., 2015). A total of 18 people were invited via email. Among them, 17 responded (response rate=94%), and 14 agreed to participate in the study. Included were nine municipal government staff and three consultants, one regional government staff, and one academic researcher. Nine participants considered themselves as urban foresters, 42 three as urban planners, and two as landscape architects1. They had been practicing in the fields that they identified for a range of 4 to 35 years (average 19 years). Each participant was individually interviewed for 30-75 minutes, depending on their availability. Participants responded to a list of pre-developed questions on synergies and trade-offs among polices related to climate action, related urban planning, and urban forestry that they had encountered in their work, as well as potential solutions to resolve the identified trade-offs (see the full list of interview questions in Appendix B.1). 3.2.3 Data analysis All interviews were recorded and transcribed with the permission of participants, before being imported to NVivo 12 for further analysis. A combination of inductive and deductive thematic analyses of the transcribed interview data was conducted (Braun & Clarke, 2006). Transcriptions were first coded into three pre-developed themes (or nodes) based on the research questions — trade-offs, synergies, and solutions (Table 3.1). Under each theme, inductive coding was conducted where new sub-themes (i.e., child nodes) were developed based on the data. An additional theme (node), contributing factors to synergies or trade-offs, was developed in the inductive coding process. These contributing factors were further divided into two categories: Contextual factors and structural/operational factors. Contextual factors are about the broader circumstances and environment that influence municipal priorities and that the municipal government has little control or influence over (Burch, 2010). Structural/operational factors are about the organizational structures as well as the procedures that influence the policy making and implementation processes (including key stakeholders that have influence over policy making and implementation) (Burch, 2010). 1 Some participants considered themselves practicing in more than one field (e.g., in urban forestry and urban planning). In this case, only the participant’s primary profession was considered here. 43 Table 3.1 Definitions of key nodes in the interview transcript coding process Nodes Definitions Contributing factors (of trade-offs/ synergies) (derived node) Factors (phenomena, events, projected trends etc.) that contribute to the occurrence of synergies or trade-offs. Synergies (i.e., 1+1≥2) (pre-developed node) A combined effect as a result of cooperation of two features, processes, or policies that is equal or larger than the sum of the desired effects of individual policy/feature/process (Lexico.com, n.d.-a). Trade-offs (i.e., 1+1<2) (pre-developed node) Conflicts or compromises between two policies, or between two desirable processes or outcomes during or after the implementation of policies (Lexico.com, n.d.-b). Solutions (pre-developed node) Measures that help alleviate/resolve trade-offs or their contributing factors. These measures can potentially become opportunities for cities to sustain or enhance the synergies. To get a full picture of the relationships among policies, the deductive analysis of synergies and trade-offs considered the full policy-implementation-outcome spectrum, i.e., synergies and trade-offs between policies themselves as well as the implementation process and outcomes of these policies. Therefore, in the coding process, synergies and trade-offs were further categorized into three types, based on where and when the interactions occurred (Figure 3.2): • Policy synergies/trade-offs: synergies or trade-offs between policies, • Implementation synergies/trade-offs: synergies or trade-offs that occurred in the process of implementing policies, usually involving a decision-making and/or implementation process that conflicts with the implementation of urban forestry policies, such as tree planting or retention, and • Outcome synergies/trade-offs: synergies or trade-offs between the implemented outcomes of policies, such as newly planted trees as a result of an urban forest policy 44 Figure 3.2 Conceptual relationships of key nodes being coded Key nodes are in boxes, including synergies and trade-offs between climate and related policies/actions and urban forestry policies/actions that occurred in the policy-implementation-outcome spectrum, their contributing factors, and solutions. The dotted arrows indicate the potential connections between nodes related to contributing factors and solutions and nodes related to synergies/trade-offs. 3.3 Results The study findings reported here are organized into three sub-sections: synergies and contributing factors, trade-offs and contributing factors, and solutions for addressing trade-offs. As mentioned, all synergies and trade-offs were specifically about the relationships of climate policies, urban planning policies, and urban forestry policies, as well as implementation processes and outcomes of these policies. Table 3.2 summarized the synergies and trade-offs as mentioned by interviewees. 45 Table 3.2 Overview of the identified synergies and trade-offs among climate policies, urban planning policies, and urban forestry policies, and their implementation processes and outcomes. Table cells were coloured to indicate the number of participants who discussed each synergy or trade-off: Light green = discussed by 1-3 participant(s) Light red = discussed by 1-3 participant(s) Medium green = discussed by 4-6 participants Medium red = discussed by 4-6 participants Dark green = discussed by 7+ participants Dard red = discussed by 7+ participants Sectors Synergies Trade-offs Policy Implement. Outcome Policy Implement. Outcome Urban Forestry & (Re)development ✓ ✓ ✓ N/A ✓ ✓ Urban Forestry & Climate Action ✓ ✓ ✓ N/A N/A N/A Urban Forestry & Infrastructure ✓ ✓ ✓ N/A ✓ ✓ Urban Forestry & Environmental Sustainability ✓ ✓ ✓ N/A N/A N/A Within Urban Forestry N/A N/A N/A N/A ✓ N/A 3.3.1 Synergies with urban forestry policy implementation and contributing factors The synergies that participants discussed (n=11) could be categorized into four areas, including synergies with (re)development (n=8), synergies with climate actions (n=6), synergies with infrastructure (n=5), and synergies with broader environmental sustainability initiatives (n=5). Appendix B.2 provides details of each identified synergy and the number of participants who discussed them. 3.3.1.1 Synergies with (re)development (Re)development here refers to projects that construct new properties or convert existing built properties into a new form or use. The synergies related to 46 (re)development with urban forests were most commonly mentioned (n=8). Ten synergies between (re)development and urban forests were discussed, including seven implementation synergies (n=8), two policy synergies (n=3) and one outcome synergy (n=1). Participants considered (re)developments as an opportunity to increase or improve green space. As the city densifies with more efficient land uses, more tree-friendly space (e.g., pervious surface with sufficient soil volume underground) could potentially be preserved and/or created. The identified policy synergies mainly reflected the shared goal of creating safe, climate-resilient, and green public space (e.g., streets) in climate and urban forestry policies (n=3). For example, tree planting requirements (e.g., number and type of trees to be planted) were specified in some cities’ subdivision and servicing bylaws or community plans for (re)development projects with an aim to build a greener, safer and more walkable community (n=2). Similarly, most implementation synergies here focused on increasing tree planting opportunities on public land, including opportunities to acquire land for new parks through development processes (n=2), initiatives to increase street tree planting to encourage active transportation (n=2) and calm traffic (n=2). The inclusion of tree planting specifications (e.g., soil volume and types) in engineering documents facilitated the communication and coordination between engineering and urban forestry departments on street tree planting (n=1). The viewscape requirements for older neighbourhoods in Vancouver were the only outcome synergy identified in this study. Viewscape considerations required space between tall buildings, which preserved space for trees (n=1). Although the viewscape requirements are no longer in effect, they have a legacy impact on preserving mature private trees in some old neighbourhoods in Vancouver (e.g., West End) (Metro Vancouver, 2019b). The ecological and social benefits provided by the preserved trees are additional synergistic effects as a result of implementing the viewscape requirements. 3.3.1.2 Synergies with climate action Climate action here refers to the measures that municipal governments take to specifically tackle climate change issues. The synergies between climate action and 47 urban forests were mainly centered around climate change mitigation and adaptation. Three of the six synergies identified were policy synergies. Climate policies recognized the role of urban forests in climate change mitigation and adaptation (e.g. carbon sequestration and stormwater management) and integrated urban forest related goals (e.g., tree planting and restoring naturalized areas) (n=5). Implementation synergies, as a result of policy synergies, were mainly about the collaborative process that participants had witnessed or experienced among different municipal departments to implement measures that also encourage or enhance the process of planting, managing and protecting urban trees (n=3). Some climate measures that aimed to reduce people’s reliance on cars could potentially create opportunities to rezone the car space for trees in the future. Only one outcome synergy was identified — more trees being planted with green infrastructure projects for stormwater management purposes (n=1). 3.3.1.3 Synergies with infrastructure Infrastructure in this study refers to the physical structures and systems that provide essential utilities and services to a city (e.g. water, energy, transport, electricity, streets and highways) (Ferrer et al., 2018). Synergies were found between green infrastructure2 policies and urban forestry policies, as well as in the process of maintaining infrastructure and planting trees, as urban forests could alleviate pressure on the existing stormwater utility systems and reduce utility bills (as a synergistic effect). As a result, interviewees reported more tree planting initiatives were planned and carried out collaboratively with engineering departments (n=5). 3.3.1.4 Synergies with environmental sustainability The synergies related to environmental sustainability were reflected in the integration of urban forests into various environmental sustainability policies and initiatives (e.g., 2 Green infrastructure is a bioengineered system comprised of vegetation, soil, and drainage primarily for stormwater management purposes (Metro Vancouver, n.d.). This study considers green infrastructure as a type of infrastructure that is separate from urban forests, as green infrastructure planning and management is usually done by a different department from the urban forestry team and is guided by a green infrastructure specific policy (different from the urban forest/tree policy) in most cities in Metro Vancouver. 48 biodiversity and sustainability policies) (n=4), which promoted collaborative policy implementation processes (n=3). As a result of the integration, one interviewee reported trees being planted and protected for environmental sustainability purposes despite the densification process. 3.3.1.5 Contributing factors of synergies Four contributing factors were discussed by participants during the interview (n=11), as summarized in Figure 3.3. All the contributing factors of synergies were structural/operational factors. The major contributing factors that linked with all categories of synergies were the connections with political agenda (n=10) and the understanding and recognition of urban forest values among city staff (n=9). Participants recognized a wide variety of urban forest values that connected with political agenda, including ecological values (e.g., biodiversity enhancement), economic values (e.g., increase of property values and commercial sales), and social values (e.g., traffic calming effects, and public health benefits). Considering all the benefits that urban forests could provide, they were deemed as a cost-effective measure (n=2). Collaborations with engineering, climate action, and development departments on greening projects contributed to anticipated and observed (re)development, climate action, and infrastructure related synergies (n=5). The public’s desire for more trees and green space also encouraged the integration of more trees in (re)development projects (n=4). 49 Figure 3.3 Relationships between synergies and their contributing factors The numbers in brackets are the number of participants who discussed the contributing factor (n=14). “UF” in the figure stands for “urban forest”. 3.3.2 Trade-offs with urban forestry policy implementation and contributing factors Trade-offs identified by participants centered around three main areas: trade-offs between (re)development and urban forests (n=11), trade-offs between infrastructure/utilities and urban forests (n=10), and trade-offs between urban forest management priorities (n=2). No evident trade-offs between policies were identified specifically by participants. However, a range of implementation and outcome trade-offs were identified by the participants. See Appendix B.3 for a complete list of trade-offs and their descriptions. 3.3.2.1 Trade-offs with (re)development (Re)development-related trade-offs were the most commonly mentioned category (n=11). Participants generally believed that (re)developments could significantly impact the implementation process of urban forestry policies, mainly due to space limitations and undesirable growing environment for trees. (Re)developments can also conflict with 50 the implemented outcomes of urban forestry policies, as participants had witnessed increasing (re)development often leading to increased tree vulnerability and tree removals. A total of eight implementation trade-offs (n=10) and five outcome trade-offs (n=9) were identified by participants. Implementation trade-offs The most commonly mentioned implementation trade-off was increasing urban density (n=7) through rezoning processes to enable measures such as allowing a higher floor space ratio and infill developments. It was considered a significant trade-off with efforts to retain existing mature trees or implement tree replacement requirements due to the loss of plantable space. The trend of increasing urban developments (n=4), including urban densification and expansion, was identified as a trade-off with implementing urban forestry policies. Increasing developments usually resulted in a number of issues for trees, such as more impervious surface, less soil volume and few or no native soil resources, significantly limiting growing space and conditions for trees to reach maturity. Three trade-offs were specific to private (re)developments (e.g., residential developments by individuals and private developers), including the flexibility provided for developers on tree retention and replacement (n=5), parking requirements (n=4), easements into private land (n=2) and riparian setback requirements (n=1). Interviewees reported that some cities were willing to relax tree retention and replacement requirements (e.g., allowing cutting of mature trees and lowering the requirements for replacement trees), which created additional barriers to implementing tree protection bylaws and fulfilling urban forestry targets (e.g., on tree canopy and tree planting). Parking requirements for residential buildings (e.g. providing a minimum of one parking stall per residential unit) were cited as another trade-off with tree planting and replacements on (re)developed lots. The parking space (especially underground parkades) and driveways not only limited available soil volume and permeable areas but increased the costs of creating plantable space for trees. In some cases, cities allowed a small easement into private land to expand the public realm for trees and other greeneries. However, this practice further intensified space conflicts, as it restricted 51 already limited private space (particularly for lots with underground parkades) and soil volume available for street trees planted in the easement area. Reduced riparian setback requirements could become a trade-off in cases where developers were allowed to build residential units very close to the edge of forested riparian corridors, according to participants. Residents in these units could be more exposed and vulnerable to forest related risks such as wildfires, thus requiring more risk management efforts from already resource-limited urban forestry teams. The practice of planting trees on structures (e.g., in raised planters or on building roofs), often seen in dense areas, was cited as a trade-off with the efforts to increase urban tree health and longevity (n=2). Most trees on structures did not grow to optimal size due to space constraints, and their lifecycles were determined mostly by the structure’s lifecycle. Trees on structures (e.g., raised planters) were seen as costlier and more difficult to maintain, which created additional funding and capacity barriers for urban forestry teams. Rooftop trees or gardens also contradicted the goal and process to increase equitable public access to urban green space (n=2). Outcome trade-offs Similar to implementation trade-offs, the most commonly discussed outcome trade-offs were the impacts of densification (n=5) and (re)development overall (n=4) on existing trees. The issue of poor tree health and tree losses was mentioned to be particularly severe in dense areas or greenfield development sites. The flexibility offered to developers in fulfilling tree planting or protection requirements (n=3) led to removals of healthy and mature trees (in some cases on protected parkland) and exemptions for planting replacement trees. The use of reflective building materials for energy-saving purposes could intensify urban heat issues and therefore impose adverse impacts on the health of surrounding trees. In addition, as mentioned earlier, trees planted on structures tended to have a shorter lifecycle than trees on the ground due to limited soil and growing space for trees, which conflicted with the outcomes of implementing urban forestry policies (i.e. planting healthy trees). 52 3.3.2.2 Trade-offs with infrastructure Infrastructure-related trade-offs, discussed by 10 participants, were the second most commonly mentioned category. Participants believed that the setback requirements for grey infrastructure (e.g., buildings, driveways, water pipes) were a major barrier to implementing urban forestry policies (e.g., planting street trees or increasing park space). Existing infrastructure could also lead to removals of healthy trees for various reasons, such as public safety considerations and space constraints. Ten implementation trade-offs (n=10) and six outcome trade-offs (n=9) were discussed by participants under this category. Implementation Trade-offs The implementation trade-offs could be further categorized into four groups: Ground-level infrastructure (n=8), underground infrastructure (n=4), overhead infrastructure (n=1), and general infrastructure where their locations were not specified (n=6). Ground-level infrastructure (e.g., driveways, bike lanes and street lights) and underground infrastructure (e.g., underground utilities and parkades) and their setback requirements reduced the plantable space for trees (i.e. surface permeable area, underground soil volume and root space), which made tree planting and management more challenging. Among them, installing grey infrastructure for automobiles was the most commonly mentioned trade-off (n=6). Participants said that urban forestry teams could face doubts or rejection of tree planting near underground utilities due to the perceived risks and damages to other infrastructure (n=3). Two participants mentioned the trade-off in the use of street space between ground-level grey infrastructure and trees, which was a balance that urban planners, engineers and urban foresters constantly needed to maintain (n=2). Overhead power lines could lead to additional tree maintenance work (e.g., pruning) due to tree growth, especially if inappropriate tree species were planted under the powerlines (n=1). Six participants mentioned that infrastructure overall made tree planting and retention difficult because of various setback requirements and limited tree-friendly space (n=6). Outcome trade-offs 53 Similar to the implementation trade-offs, grey infrastructure for automobiles was the most discussed outcome trade-off (n=3). Participants had observed that constructing more car infrastructure, such as parking and driveways, had led to tree removals due to lack of space. Similarly, the increase of active transportation infrastructure as part of cities’ climate action plans had been a trade-off with retaining existing trees on the ground for the same reason (n=2). Water and electricity infrastructure (e.g. water pumps), if located in parks, could reduce park areas available to the public or even reduce the accessibility to park temporarily if the park needed to be excavated and rebuilt (n=2). Ornamental lighting created tree health issues or tree failures if not properly maintained (n=1). One participant mentioned the trade-off between installing new green infrastructure in an area with existing large trees and holding off the installation in order to preserve the trees. 3.3.2.3 Trade-offs between urban forest management priorities Urban forest management priorities refer to the management practices of urban forests that are considered important in order to fulfill the goals and targets set by urban forestry policies. Two participants discussed the conflicts that occurred within urban forest management work: 1) between increasing urban forest species diversity and prioritizing to plant species preferred by the public (e.g., Prunus and Acer), especially if the publicly preferred species were already overrepresented in urban forest population (n=1); 2) between managing wildfire risks (e.g. removing hazard trees and avoiding or reducing planting in places close to residential areas) and planting more trees where possible (n=1); and 3) between tree maintenance (e.g., removing dead trees, grinding tree stumps, and pruning) and tree planting (including replacement planting of dead trees and planting new trees to meet the tree planting or tree canopy targets), given the limited capacity of the urban forestry teams (n=1). 3.3.2.4 Contributing factors of trade-offs Six contributing factors to the occurrence of the above-mentioned trade-offs were mentioned by all participants (n=14), including 4 structural/operational factors and 2 54 contextual factors. Figure 3.4 illustrates the connections between different categories of contributing factors and identified trade-offs with urban forestry policies and implementation. Figure 3.4 Relationships between trade-offs and their contributing factors The numbers in brackets indicated the number of participants who discussed the contributing factor or trade-off during the interview (n=14). “UF” in the figure stands for “urban forest”. Most participants (n=13) discussed the contextual factor of population growth and densification. Population growth has created more demands for new housing and infrastructure (e.g., for transport and water cycling), which has intensified the competition for space with trees. Competition over space also led to higher land values and construction costs (e.g., for underground parking), making it more expensive to preserve sufficient space for trees. In addition, concern over climate change could drive densification and other climate measures (e.g., increasing active transportation and transit infrastructure), which unintentionally could further intensify competition for space 55 with trees (n=4). Climate change impacts (e.g., extreme heat and droughts) could also compound with development impacts on trees (e.g., increased impervious surface and more intensified urban heat island effects), creating more barriers to urban forestry practices. When it comes to structural/operational factors, the low priority of urban forests on the political agenda was the dominant factor that contributed to all three categories of trade-offs (n=14). This was reflected in several ways, including the lack of strong policies for tree protection, retention, and (re)planting (n=12), weak political will to support urban forestry planning and management (n=7), limited capacity of urban forestry teams (n=6), and the lack of willingness to adopt creative tree-friendly solutions to the trade-offs (n=3). Limited understanding of urban forests among city staff (n=10) as well as the public’s and developers’ opinions which undervalued urban forests (n=9) also contributed to the occurrence of trade-offs. Interviewees felt that developers' and the public's opinions could have a significant impact on political will and policy direction. For example, municipal governments often faced questions from the public and developers regarding housing affordability issues, which became a barrier to preserving space for trees and other green space. Within the municipal government, the prevalent risk aversion mindset of city staff was considered a major contributing factor to various (re)development- and infrastructure-related trade-offs: e.g. trees were often deemed as a risk if close to sidewalks and underground pipes, resulting in trees being removed or not planted. Lastly, limited collaboration and coordination across city departments on urban forestry projects also contributed to the occurrence of (re)development- and infrastructure-related trade-offs (n=7). 3.3.3 Solutions for addressing trade-offs The following six sub-themes summarized participants’ ideas about potential solutions to overcome the above-mentioned trade-offs. Interestingly, each sub-theme (as a result of inductive coding) could be linked with at least one contributing factor of trade-offs, rather than trade-offs themselves (Figure 3.5). For example, the need to increase the political priority of urban forestry was connected to one of the main contributing factors 56 of trade-offs: low political priority of urban forestry. Since most of the contributing factors of synergies and trade-offs fell in similar areas, the identified solutions could be connected to the contributing factors of synergies, suggesting that these solutions to trade-offs could be seen as potential opportunities to sustain or enhance synergies as well. Figure 3.5 Connections between solutions and the contributing factors of trade-offs The arrows indicate the potential connections between identified solutions and contributing factors of trade-offs and synergies Increase priority of urban forestry All participants mentioned the need to increase the priority of urban forestry to address trade-offs, possibly because lack of priority given to urban forestry was considered as one of the main causes of various trade-offs. In explaining how to do this, most participants (n=9) emphasized the importance of providing adequate policy support for urban forestry work, such as introducing more comprehensive urban forestry policies with a long-term (e.g., 100 years) vision, reasonable and trackable (i.e., measurable) targets and sufficient technical guidance on urban forest management (n=6), and 57 establishing adequate policy monitoring and adjustment processes (n=5). Other suggested approaches included providing enabling incentives for tree protection (e.g. exemption of tree removal fine or allowing taller buildings with smaller building coverages) (n=4), integrating urban forests in asset management programs (n=2), prioritizing tree space in land use planning (n=2), and integrating urban forests into growth policies to ensure existing trees and their habitats were well protected in the urbanization process (n=1). Participants also stressed the importance of building a stronger political will (n=6), but no specific approaches were identified in the interviews. More and better collaboration Collaborations were deemed critical for smooth and effective policy implementation (n=12). Core aspects of collaborations included enhancing cross-departmental collaborations (e.g., with engineering and transportation departments) (n=8), engaging key stakeholders (e.g., developers and community members) (n=4), fostering a collaborative environment (n=2), and communicating effectively about each stakeholder’s concerns and potential solutions (n=2). More research and innovative experiments Eleven participants noted the need to conduct more research and innovative experiments to better understand the baseline and projections of urban forests (e.g. urban forest’s ecosystem services and disturbances to urban forests), the effects of climate change and utilities on trees, and the potential of private lands to increase urban tree canopy. These efforts could provide more local examples and resources (n=5) and support tree-friendly designs (n=7), resulting in better urban forestry policy formulation and implementation. Better tree protection and management measures Stronger tree protection and management measures, according to nine participants, could help resolve trade-offs, especially between densification and urban forestry. These included increasing soil volume, acquiring lands for tree planting, or using underutilized space (n=8) to protect and/or improve tree habitats. Other tree 58 management measures included exploring vertical greening opportunities (n=4), proactive planning for tree retention/protection (n=3), selecting and planting adequate species (n=3), and adopting tree-friendly designs (n=2). Better and more education Education could help stakeholders (e.g., city staff, politicians, and community members) better understand the services and disservices of urban forests (n=3), and shift their perceptions of urban forest related issues (n=2). It could lay a core foundation for deeper engagement and collaboration on urban forest management among stakeholders. More funding and resources The need to access more funding and resources for urban forestry and greening work was highlighted (n=5). Municipalities could collect funding for tree planting and park creation/acquisition from (re)development projects (n=2). This mechanism has been in place in several cities in Metro Vancouver (e.g., City of Surrey, n.d.; City of Vancouver, n.d.). 3.4 Discussion 3.4.1 Identified synergies and trade-offs among climate, urban planning and urban forestry policy realms Previous studies have highlighted the importance of adequate policy support (e.g., support from political agenda and proper policies and regulations) and operational capacity to the success of urban forestry policy implementations (Ordóñez et al., 2019). This study, however, highlighted another need that appears to be under-studied in previous research: the need to properly plan and coordinate with policies and processes beyond urban forestry. In this study, participating experts identified various trade-offs and synergies among climate action, related urban planning and urban forestry policy realms, at the levels of 59 policies, implementation processes and outcomes. Urban forestry policies can synergize with municipal policies in areas of (re)development, infrastructure, climate actions, and other environmental sustainability initiatives, through directly or indirectly contributing to climate-change mitigation and adaptation, urban livability and resilience, and public health and well-being (Janowiak et al., 2021; Nowak & Crane, 2002). However, participants revealed many more trade-offs than synergies between urban forestry and other policy realms, particularly in the implementation processes and outcomes of these policies. These trade-offs or conflicts centered mostly around (re)development and infrastructure, and within urban forest management priorities. The trade-offs were caused or intensified by a combination of factors, including population growth and densification, the low priority of urban forestry on political agendas, and limited understanding of urban forests among city staff, developers, and the public. These factors were also issues identified in existing studies on urban forest governance and management (e.g., Boulton et al., 2018; Ordóñez et al., 2019). 3.4.2 Discrepancies between synergies and trade-offs: problems in the policy-implementation-outcome spectrum? One interesting but unexpected finding is that the identified synergies and trade-offs occur between policies at different levels. The synergies usually happen between city-wide strategic policies, such as climate action plans, regional growth policies, or urban forestry strategies. In many cases, expected synergies (e.g., planting more street trees for stormwater management) are mentioned in the strategic policy documents explicitly (Cheng et al., 2021). However, due to the influence of various social, political, organizational, and environmental factors (e.g., limited budget, conflicted stakeholders’ interests, and different interpretations of policies), policies often are not implemented in the ways expected, and trade-offs and compromises happen (Smith, 1973; Urwin & Jordan, 2008). This situation is consistent with what has been found in this study: trade-offs more often occur between implementation processes or outcomes, according to the participants’ experience. Despite the recognition of synergies in strategic policies, trade- 60 offs in on-the-ground operations can become a significant barrier to fulfilling high-level strategic goals. The lack of apparent policy-level conflicts suggests that problems inherent in these separate policies, when applied in conjunction with other key policies, become evident only during implementation and afterwards, which is too late. In this study, participants identified more implementation trade-offs than outcome trade-offs (15 versus 11), emphasizing the need to map and understand inherent policy conflicts and the importance of coordinating on-the-ground operations and the involved/responsible teams during the implementation process. Implementation trade-offs can also impact implemented outcomes (Smith, 1973). For example, despite ambitious urban forestry goals and policies, trade-offs occurred in the implementation process (e.g., the localized decision-making process to strike a balance between densification and tree protection) leading to a declining overall urban forest canopy while gaining imperviousness in municipalities of the Metro Vancouver region (where data is available) since 2009 (Metro Vancouver, 2019b). Similar examples can be found in cities outside of Canada (Nowak & Greenfield, 2020). Cities globally have lost about 40,000 ha of tree canopy per year during 2012-2017, with the greatest loss found in Africa. Meanwhile, an increase in impervious area has occurred in cities across the world (Nowak & Greenfield, 2020). The inherent trade-offs also highlight the importance of proper monitoring mechanisms to evaluate the effectiveness of policies and ensure the policies are implemented for the intended and desired outcomes. However, many Canadian cities still do not have monitoring programs in place and many still rely on passive information collection or informal reporting (Conway & Urbani, 2007; Ordóñez & Duinker, 2013). This issue is not unique among Canadian cities. For example, a review of 39 urban forest management plans in Washington State discovered that very few plans mentioned monitoring and adaptive management and none included a detailed monitoring plan (Gibbons & Ryan, 2015). As participants mentioned, policies are developed to provide short-, medium-, and long-term directions and goals, therefore there could be a long gap between when 61 the policy was adopted and when the implementation started. Having a proper monitoring mechanism allows the city to not only timely track the progress of policy implementation, but also make adjustments according to emerging and/or unexpected changes for improved results if needed (Baines et al., 2020; Dwyer et al., 2003). Evidence from this study and previous research suggests that urban forests are a relatively low priority, compared to housing development and affordability and grey infrastructure, which is the most commonly mentioned contributing factor to trade-offs (Boulton et al., 2018; H. J. Davies et al., 2017). Several participants described tree protection bylaws as “subsidiary” to zoning bylaws, “reactive” in nature to tree losses and “limited in the scope of what they can do” (quotes of participants). As a result, trees are often cut down to make way for infrastructure and buildings approved by other departments (Brunner & Cozens, 2013). Being a low priority on the political agenda can trigger a cascade of other issues. The importance of inter-departmental collaboration and coordination, as a key contributing factor to synergies, was well recognized by participants and in previous studies (e.g., Cheng et al., 2021; Ordóñez et al., 2020) due to synergies among urban forests, climate change adaptation, and community building. However, most participants stated the urgency and importance of more collaborations due to the siloed environment of many municipal departments (Larsen et al., 2012b; Nitoslawski et al., 2019). Insufficient funding and capacity of urban forestry teams, potentially due to the low priority of urban forestry issues, was reported as a cause of trade-offs and compromises in urban forest management work. Another related issue is the prevalence of a risk-averse mindset among city staff generally when it comes to planting and retaining trees, even when trees are not a significant risk factor (Ordóñez et al., 2020; van der Jagt & Lawrence, 2019). Trees may be prevented from being planted anywhere near infrastructure to avoid any potential risks or harms. The risk aversion culture within municipal departments, which usually stems from limited understanding of urban forests, also becomes an important impediment to meaningful collaborations for creative tree-friendly solutions (Ordóñez et al., 2020). Resolving the issue requires a more thorough 62 understanding of urban forests, supported by convincing local examples and data, which are currently not available in many cities, according to the participants. Population growth/densification and climate change impacts were the two contributing factors identified only for trade-offs (not for synergies). Despite the potential for increasing urban forests in (re)development process, population growth and associated urbanization, such as greenfield developments, often lead to urban forest declines for various reasons, such as increased impervious surface (Nowak & Greenfield, 2012, 2018) or reduced and changed soil quality (Chen et al., 2014; Guo et al., 2019). Metro Vancouver’s densification appears inevitable as the population increases, due to the Regional Growth Strategy and urban containment boundary (Metro Vancouver, 2021), putting even greater pressures on urban forests (Metro Vancouver, 2019b). These effects, compounded with climate change impacts on trees (e.g., urban heat and droughts), may make urban areas a more hostile environment for trees (Ordóñez & Duinker, 2015) and therefore for people. With the recent shock and precedent of the heat dome in 2021 (British Columbia Coroners Service, 2022), the ongoing mismatch of policies appears to increase the risk of climate change in urban communities by failing to provide easily and freely accessible cooling resources to those in need. While other non-nature-based methods, such as air conditioning, are available, a healthy, well-canopied urban forest represents the primary nature-based method of climate change adaptation in urban regions, such as Metro Vancouver (Diamond Head Consulting Ltd., 2017; Lu et al., 2022; Paschalis et al., 2021). 3.4.3 Overlaps between synergies and trade-offs: where opportunities arise? Despite the above-mentioned differences, most of the identified trade-offs and synergies occur in the same areas, namely (re)development and infrastructure. This is supported by other studies: for example, (re)developments are causing a rapid decline of urban forests (especially a loss of mature canopy) when they are not properly planned and designed to protect trees (Croeser et al., 2020; Guo et al., 2019; Lantz et al., 2021). Participants, however, also see (re)developments as a potential synergy with 63 urban forests because they offer a great opportunity to recreate a more tree-friendly environment and plant new trees. The overlap between trade-offs and synergies suggests the possibility of enhancing urban forest quantity and/or quality in the (re)development and infrastructure management processes. Many cities have taken novel approaches to increasing urban forests in the (re)development process, such as requiring street and private tree planting (City of Coquitlam, n.d.; Martin, 2017), acquiring land for green space (Metro Vancouver Regional Parks Service, 2018; Robinson & Brown, 2009), and converting brownfield and underutilized land (e.g. railroads) into new parks during the (re)zoning or (re)development process (Boulton et al., 2018; Wolch et al., 2014). Successful examples of maintaining or even increasing green space exist in rapidly urbanizing areas such as China (Wu et al., 2019; Zhao et al., 2013) and Singapore (Tan et al., 2013), due to early integration of urban greening planning and strong political support for the protection and enhancement of urban forests and other green space. Metro Vancouver has also demonstrated some past successes in retaining trees in high-density areas (especially between 1960 and 1980) (Metro Vancouver, 2019b). However, more local examples are needed to support the planning and implementation of policies to enhance urban forests despite densification, as suggested by the participants. The study identified several key factors contributing to both synergies and trade-offs in Metro Vancouver, including city staff’s awareness and understanding of urban forests, public attention and opinions of urban forests, priority/connection with political agendas, and collaborations and coordination among various stakeholders. These are consistent with previous findings related to challenges of urban forest governance and management (Haaland & Konijnendijk van den Bosch, 2015; Ordóñez et al., 2019). In this study, political priority and understanding of urban forest values were the most-mentioned contributing factors for both synergies and trade-offs. The connections suggest that these factors (i.e., awareness and knowledge, political priority, and collaborations) are key ingredients in creating synergies amongst urban forestry, climate action, and urban planning in the policy-implementation-outcome spectrum. These are 64 also the key areas in which cities can fail to accomplish their urban forestry aims at the same time as their climate action and urban planning aims, thereby missing out on opportunities to efficiently grow their urban forests and increase livability while simultaneously acting to reduce their carbon emissions (Cheng et al., 2021; Ordóñez & Duinker, 2015). Urban foresters are already facing trade-offs and compromises induced by urbanization and climate change (e.g. tree planting versus wildfire risk management) and other aforementioned factors (Brandt et al., 2016; Jim, 2017). In order to maintain or grow urban forests in densifying areas, cities must increase the priority of urban forestry issues on the political agenda, integrate urban forests in the early stage of planning processes, and proactively coordinate interconnected but distinct policies, such as climate action plans, rezoning plans, and urban forestry management plans, as well as their implementation processes and outcomes. The findings of this study also highlight the importance of increasing the understanding of urban forest services and disservices through local research and education and the urgency to improve collaborations within and beyond municipal departments (e.g., community members, professionals and practitioners in climate/sustainability planning, engineering, development planning and management. While not specifically mentioned by study participants, the use of modelled scenarios of intersecting policies to quantify potential outcomes (e.g., densities, tree losses/gains, and cumulative canopy levels over time) would seem to be a logical and valuable solution to address the awareness gap and inherent policy conflicts in policy-making and urban planning decisions. 3.4.4 Limitations and future research The study has several limitations that provide opportunities for future research on similar topics. First, the study is focused mainly on the perspectives of urban forestry practitioners and allied professionals, with the majority of participants being trained in urban forestry or a closely-related field. Future studies should explore perceptions and experiences of synergies and trade-offs of practitioners from other more well-established fields that interact with urban forestry policy implementation, such as 65 transportation planning, utility management, asset management, and private developments, to gain a more comprehensive understanding of the synergies and trade-offs that they experience. Future studies should also consider a larger sample size for semi-structured expert interviews, which would permit analysis of the differences between disciplines in their views on synergies and trade-offs. Although no clear guidelines or standards are available in terms of adequate sample size for qualitative research, previous research has recommended a range of 20 to 60 participants for interview-based studies (Sheppard et al., 2017; van der Jagt & Lawrence, 2019). Finally, more studies in different cities/regions are needed to understand locally specific trade-offs and synergies, given the differences in governance approaches, climate change issues experienced locally, and urban forest conditions. 66 Chapter 4: Urban forestry policy interventions to create a walkable, green, and resilient city 4.1 Introduction As more cities start to integrate urban forests into their climate change policies, unintended tensions and conflicts occur. In the previous chapter (Chapter 3), key trade-offs and synergies among policies and practices related to climate action, urban planning, and urban forestry were identified. Most of the identified trade-offs and synergies occurred in the areas of (re)development and infrastructure. The connections between the identified trade-offs and synergies highlighted potential opportunities for cities to address trade-offs and transform them into synergies for climate resilience, urban greening and livability. (Re)development, including new development and redevelopment of existing developed areas, is prevalent in cities with aims to increase density, enhance land use efficiency, improve walkability and lower greenhouse gas emissions (Brunner & Cozens, 2013). However, (re)development often imposes substantial and adverse impacts on trees and other vegetation (Brunner & Cozens, 2013; Guo et al., 2019; Haaland & Konijnendijk van den Bosch, 2015). Land is cleared during new and re-development processes, often resulting in major urban forest losses (Brunner & Cozens, 2013). Construction during (re)development projects also creates an undesirable environment for trees, such as sites dominated by heavy traffic, compacted soil, and machinery damage, causing tree health issues, decline and removals (Haaland & Konijnendijk van den Bosch, 2015; Jim et al., 2018). Several studies have found evidence of the major influences of redevelopment and associated construction on the decline and uneven distribution of urban forests (Brunner & Cozens, 2013; Guo et al., 2019; Koeser et al., 2013). Similar to the concerns related to (re)development, infrastructure (especially grey infrastructure) can significantly reduce the space available for trees due to the setback 67 requirements of certain infrastructure, such as sidewalks, underground utilities, and light facilities (Chapter 3; City of Vancouver, 2018). Most of the conflicts between infrastructure and urban forests are related to space. Underground, issues arise from insufficient and poor-quality urban soils that cannot support adequate tree growth (Mullaney et al., 2015; Staley, 2012). Above-ground, the increase of impervious surface for built infrastructure reduces permeable plantable areas for new trees and can cause tree health issues for existing trees (Diamond Head Consulting Ltd., 2017). Above-ground infrastructure, such as power lines, limits the room for trees to grow their canopy (Diamond Head Consulting Ltd., 2017) and the choices of species with a low enough mature height to grow under the current above-ground infrastructure without conflict (Staley, 2012). Despite the above-mentioned trade-offs and conflicts, many cities have implemented various urban forestry policy interventions with an aim to offset the loss of urban forest canopy or area. For example, cities are introducing ambitious planting programs (e.g., New York’s Million Tree Program) to sustain public tree canopy and encourage residents to plant or care for their private trees (Guo et al., 2019; MillionTrees NYC, 2015). In many cases, parks, streets, and other public spaces are usually prioritized for tree planting as cities have more direct control over planting activities on public land (Garrison, 2019). In addition, the increasing integration between urban forests and green infrastructure offers cities more opportunities to plant trees as part of the green infrastructure projects on public land (e.g., streets and parks) (Chapter 3). On the other hand, the planting and management of private trees tend to focus more on a combination of “stick” (i.e., punishment) and “carrot” (i.e., incentive or reward) approaches, including incentive programs such as tree giveaway events and regulations that prevent healthy trees from being removed (Ordóñez-Barona et al., 2021). (Re)development on private land also offers opportunities for creating more tree-friendly spaces, if urban forests are integrated into the early stages of planning and design (Staley, 2012). 68 However, many cities are losing an average of around 1% of their urban forest canopy per year to private development and infrastructure (Croeser et al., 2020; Y. Y. Lee et al., 2017; Nowak & Greenfield, 2012). It is evident that cities’ current efforts to limit urban forest loss are not sufficient. It is not yet clear, however, what policy interventions cities can implement to better sustain their urban forests amid the densification process and the projected climate change impacts. In addition, considering the unpredictable impacts of climate change, ever-increasing urbanization/densification, and complex urban systems with interconnected but conflicting priorities (Chapter 3), cities lack necessary information regarding the longer-term projected effects of the interventions before implementation. Therefore, it is extremely difficult for cities to make the “best” decisions that are locally-relevant, effective, and efficient. As more city governments start to introduce ambitious urban forest goals and targets, there is an urgent need for comprehensive empirical information and systematic tools to strategically plan their steps toward achieving these targets. Futures thinking and scenario planning approaches, which originated for business management purposes, are now widely used in many different fields, including urban planning and urban forestry (Barron, 2018) in the context of climate change (Sheppard et al., 2011). In previous studies which have applied these approaches to urban forestry, alternative future scenarios were created to explore opportunities to sustain or increase urban forests for certain purposes and desired future effects (Barron, 2018; Bolleter & Hooper, 2021). The research described in this chapter uses a future scenarios approach to explore a range of specific plausible urban forestry policy interventions, and assess their potential outcomes through modelling of a case study neighbourhood in Vancouver BC., out to the year 2050. This analysis builds on previously constructed ‘what-if’ urban forestry scenarios developed by the Urban Greening and Urban Densification (UGUD) Project (Czekajlo et al., minor revisions). Specifically, the study methods and findings described in this chapter aim to answer the following two research questions: 69 1) What plausible urban forestry policy interventions in the area of (re)development and infrastructure can cities implement to better sustain their urban forests despite densification and climate change? 2) What are the projected outcomes of implementing the selected urban forestry policy interventions by the year 2050? 4.2 Methods 4.2.1 Study area 4.2.1.1 Vancouver, Canada Vancouver, at 115.18 square kilometres in size and 662,248 in population, is the densest city in Canada, with a population density of 5750 people per square kilometre (Statistics Canada, 2022). Vancouver’s population grew by 30,762 in the period 2016-2021, accounting for 25% of the population growth in Metro Vancouver, the highest among all member jurisdictions in this metropolitan area (City of Vancouver, 2022b). As another million people are expected to move to Metro Vancouver in the next 30 years, it is inevitable that the City of Vancouver will continue and accelerate its densification (Metro Vancouver Regional District, 2022). Vancouver is known for its proximity to nature and beautiful urban landscapes. However, since 1998 Vancouver had been losing its urban forests, a vital part of the city’s landscape and character, primarily due to private developments (City of Vancouver & Vancouver Board of Parks and Recreation, 2018). It was not until recently that Vancouver restored its urban forest canopy back to the level of 1995. The City of Vancouver now pledges to further increase its urban forest canopy cover from 23% currently to 30% by 2050 (Vancouver Board of Parks and Recreation, 2020). Several measures have been proposed or initiated to help achieve this target, such as tailoring tree canopy targets by land use and housing type, requiring park and open space plans for large-scale development projects and increasing street tree density (measured in the number of street trees per 100 metres) (City of Vancouver, 2022a; City of Vancouver & 70 Vancouver Board of Parks and Recreation, 2018). Despite these proposed high-level measures, it is still unclear how the City will meet this target by 2050. 4.2.1.2 Sandbox area The study used a 1600m by 1600m area (i.e., “sandbox,” or simulation testing environment) as a spatial proxy for modelling, based on a real neighbourhood in the southeast of Vancouver (Figure 4.1). The sandbox was a simulation of real-world urban form and urban forest data created by the Energy Efficiency in the Built Environment (EEBE) Project and the UGUD project (sandbox methods detailed by: Czekajlo et al., minor revisions; Lu et al., 2021; Salter et al., 2020). Specifically, urban form data used for the development of the sandbox included the building and parcel data from Metro Vancouver Regional District (2020), and additional building information (e.g., building type, age and occupancy) from BC Assessment (2019). Urban forest data were retrieved from aerial laser scanning data (ALS, also referred to as LiDAR) from the City of Vancouver (2019). The sandbox models were developed by the UGUD team in 2D in ArcGIS and 2.5D in Rhino for solar radiation and cooling energy modelling purposes (Lu et al., 2021). 71 Figure 4.1 Map of the real neighbourhood (a) and its location in Vancouver, Canada (b), and the sandbox model for the baseline 2020 (c) The bottom right numbers show the comparison in urban form data among the real neighbourhood, sandbox in 2020 and sandbox in 2050. Source: imagery from Planet Team (2017), land use data from Metro Vancouver Regional District (2020), and parcel, dwelling unit, and resident counts from BC Assessment (2019). The figure was adapted from the Figure 1 in Czekajlo et al. (minor revisions). The sandbox resembles a typical neighbourhood with relatively low population density and tree canopy cover in Vancouver. Following the current population growth projections, the number of residents of the sandbox area was assumed to increase by 35%, from 15,164 in 2020 to 20,389 in 2050. As a result, given the same land area, the average floor area ratio (FAR) of parcels rose from 0.59 in 2020 to 0.76-0.77 in 2050. The urban development in the 2050 sandbox model follows the City of Vancouver’s 72 compact, complete, walkable neighbourhood policy (City of Vancouver, 2022c), concentrating redevelopment within 400 metres of the ‘corridors’ (major collector streets with commercial services in the baseline model). There are redevelopment projects3, such as infills and multi-family low-rise housing, that occur in other parts of the sandbox to replace old buildings. In the sandbox, alternative futures with different urban forestry policy interventions can be tested (e.g., planting rates, location, and scale) and their projected outcomes can be measured (Czekajlo et al., minor revisions; Lu et al., 2021). These policy interventions were spatially modelled via a semi-automatic approach using R software (as illustrated in Figure 4.2, and the detailed modelling steps are explained by Czekajlo et al. (minor revisions). A semi-automatic rule-based approach was adopted to spatially model trees in the sandboxes (Figure 4.2). To begin with, rules regarding tree mortality rates (for private, street, and park trees respectively, based on Hilbert et al., 2019), sizes, and spacing were set up to guide the semi-automatic approach to remove and allocate trees in the 2050 sandbox models (see details in Appendix C.1). The tree rules associated with different urban forestry scenarios developed for the UGUD project were set up based on the targets, goals, and actionable items extracted via a review of relevant polices in Vancouver, such as the urban forestry policies (e.g., Urban Forest Strategy, tree protection bylaw, guidelines and design manuals), green infrastructure policies (e.g., Rain City Strategy), climate change policies (e.g., Greenest City Action Plan and Climate Change Adaptation Strategy), and urban planning policies (e.g., the latest public realm plans and community plan of the real neighbourhood where the sandboxes were developed on). Following these tree rules, the process started with removing or “aging out” trees with a low climate change adaptability that were located on redeveloped parcels in 2050 (Metro Vancouver Regional District, n.d.) and were larger in size (only for street trees). These removed trees were then replaced by the “planting” of replacement trees following at least a 1:1 ratio. Finally, more trees (in addition to the 3 No new development-related policy interventions were tested here as there is no vacant land for new development in the study area. 73 replaced trees) were added to meet the total tree counts and other “targets” set for each urban forestry scenario defined by the UGUD Project (Czekajlo et al., 2022). It should be noted that this semi-automatic modelling process was completed by the UGUD project team. The author, as a member of the UGUD project team, contributed to the development of future scenario narratives, associated planting strategies, and tree rules per strategy and scenario. Figure 4.2 Illustration of the semi-automatic workflow of “aging out” and “planting” trees in the 2050 sandbox models This figure has been designed using images from Flaticon.com. Building on the UGUD project, this study identified plausible urban forestry policy interventions on private, street and park land, and used the simulated urban form and tree data of 2020 (baseline) and 2050 from the UGUD project to measure the projected outcomes of the selected policy interventions. Specifically, the data that the study acquired from the UGUD project included: urban form data per public or private parcel or street, such as parcel/street area (m2), land use types, FAR, building type, and number of residents, and urban forest data such as tree location, ownership, size category (small/medium/large), and tree crown size (i.e., diameter in metres). 74 4.2.2 Selected policy interventions This study identified and examined potential policy interventions that municipal governments could implement in redevelopment and infrastructure, the two fields where both policy synergies and trade-offs were identified in the previous chapter (Chapter 3) (Figure 4.3, Figure 4.4 and Table 4.1). The projected effects of each policy intervention on urban forest attributes (e.g., tree canopy) and livability co-benefits (e.g., people’s access to parks or other highly treed areas) were analyzed and compared (Table 4.2). All analyses were conducted in ArcGIS Pro 2.9.5. A total of 11 policy interventions were selected for analysis in this chapter. These selected policy interventions reflect what and how urban trees are planted (or removed) in the sandbox, which is the dominant approach to urban greening (Nowak & Greenfield, 2012; Young, 2011). They were selected based on the current common urban forestry goals and actions outlined in local urban forestry policies (e.g., Vancouver’s urban forest strategy) (Cheng et al., 2021; City of Vancouver & Vancouver Board of Parks and Recreation, 2018). Based on the location where these policy interventions are applied, they were further categorized into policy interventions in public jurisdiction and in private jurisdiction (Figure 4.3 and Figure 4.4). A series of policy interventions in public jurisdiction were selected because of municipal governments’ governing power over urban forest planning and management on public land (mainly streets and parks) (Ordóñez et al., 2019). On the other hand, private trees, a crucial component of urban forests, are managed jointly by property owners and the city government (Food and Agriculture Organization of the United Nations, 2018; Ordóñez-Barona et al., 2021). Often, municipal governments introduce tree protection regulations to prevent tree removals and encourage planting to ensure a certain number of trees per site (Conway & Urbani, 2007). Therefore, different tree planting requirements were tested on private land. 75 Figure 4.3 Selected policy interventions for analysis in areas of redevelopment and green infrastructure Redevelopment and infrastructure are areas where both synergies and trade-offs among climate action, urban planning and urban forestry policies were identified (in Chapter 3). This figure has been designed using images from Flaticon.com. The selected policy interventions were tested at different scales to mirror how private, street, and park tree policies and specifications are implemented in the real world, based on the current urban forestry policies in Vancouver (Figure 4.4) (City of Vancouver, 2022d; City of Vancouver & Vancouver Board of Parks and Recreation, 2018). Private and street tree policy interventions that were applied on a larger scale allowed an overview of the cumulative effects of these policy interventions, considering the relatively limited area per unit (i.e., per lot or per street segment) and the large proportion of land zoned for private and street space. Meanwhile, the park-related policy interventions were implemented on an individual park basis, which is a realistic scale for park policies and park (re)design work, given that park designs vary by site, and extensive redesign of an existing park and the creation of a new public park from private space are infrequent occurrences. 76 Figure 4.4 Maps of the locations and scales of where the policy interventions are applied (shown in dark green) In addition, two levels (moderate and ambitious) of effort were analyzed for each set of policy interventions. The only exception here was the policy intervention about tree planting on redeveloped private parcels. Only one level of effort was tested due to limited data (Table 4.1). The moderate-effort interventions are slightly strengthened efforts from the current policies/practices (e.g., planting at 1.5 times of historical planting rate), while the ambitious-effort interventions are a selection of the aggressive yet realistic greening endeavours that consider key constraining factors, such as space availability and resident’s acceptance and support (e.g., rezoning an area to create a new park). The pairs of moderate- and ambitious-effort interventions provide the municipal government alternative approaches with different levels (e.g., conventional vs. bold) of urban greening efforts and outcomes. 77 Table 4.1 Plausible policy interventions in the areas of redevelopment (private jurisdiction) and infrastructure (public jurisdiction) JURISDICTION/AREA POLICY INTERVENTIONS - MODERATE EFFORTS POLICY INTERVENTIONS - AMBITIOUS EFFORTS PRIVATE JURISDICTION: DEVELOPMENT Compliance with current tree planting requirements Compliant with Vancouver’s current requirements for the number of trees per site NA Varied private tree planting requirements Require 80% of private parcels to have at least 1 tree on site4 Require 99% of private parcel to have at least 2 trees on site PUBLIC JURISDICTION: INFRASTRUCTURE Varied street tree planting requirements Plant street trees at 1.5x historical planting rate (resulting in a total 1,512 street trees planted in addition to replacement trees)5 Plant street trees at 3x historical planting rate (resulting in a total of 3,288 street trees planted in addition to replacement trees)4 Blue-green street network Plant street tree at 1.5x historical planting rate (no blue-green street network)4 Build a blue-green street network6 on 49 selected streets (include planting of 4 rows of street trees) (see Figure 4.5 for a visualization) 4 The current requirements on the number of trees per site is specified in the Schedule C of the Protection of Trees Bylaw by the City of Vancouver. A higher number of trees are required for a larger site, and the minimal requirement is 2 trees per site (City of Vancouver, 2022d). 5 This is based on the number of trees planted over the past 30 years in Vancouver scaled to the study area (City of Vancouver & Vancouver Board of Parks and Recreation, 2018). 6 Blue-green street networks are connected streets and associated grey infrastructure (e.g., drainage system) combined with green infrastructure (e.g., trees and bioswales) designed to reduce stormwater runoff and manage flood risk. The creation of blue-green street networks can also improve urban residents’ access to urban green spaces and ecosystem services that these green spaces provide (e.g., heat mitigation and air quality improvement) (City of Vancouver, n.d.-b). The blue-green street network tested in this study involved planting 2 additional rows of street trees (i.e., 4 rows of street trees in total). 78 JURISDICTION/AREA POLICY INTERVENTIONS - MODERATE EFFORTS POLICY INTERVENTIONS - AMBITIOUS EFFORTS New neighbourhood park Compliant with Vancouver’s current requirements for the number of trees per site1 (no new neighbourhood park) Create a new neighbourhood park with over 70% tree canopy cover Varied park designs (i.e., planting approaches) Plant 2 rows of trees along park boundary in a selected park Plant tree groves with over 50% of tree canopy in a selected park Figure 4.5 Cross section of a potential blue-green street design with 4 rows of street trees This figure was created by Cynthia Girling via Streetmix (https://streetmix.net/). A list of indicators was selected to measure the results of each policy intervention (Table 4.2). They can be categorized into 1) basic urban forest indicators, 2) livability co-benefit indicators, and 3) urban density indicators. The basic urban forest indicators include several of those most commonly used in current research and practice, such as tree canopy and the number of urban trees (Croeser et al., 2020; Guo et al., 2019; Nowak & Greenfield, 2012). For example, the City of Vancouver uses the tree density indicator (i.e., the number of street trees per 100 metres) to identify tree-deficient streets and guide their street tree planting planning (City of Vancouver & Vancouver Board of 79 Parks and Recreation, 2018). Having access to urban forests and their canopy cover has important livability implications because these indicators also measure access to various benefits of urban forests, such as heat mitigation, stormwater management, and public health. Lastly, urban density indicators, such as FAR7, are commonly used in urban planning and related policies. Given the increasing efforts to encourage planting trees on private land (e.g., low-price tree sale programs or backyard tree planting services for homeowners) (City of Surrey, 2021; Local Enhancement & Appreciation of Forests (LEAF), 2022), the number of parcels with trees was selected to measure the average number of trees per private parcel. It was also a direct measurement of the outcomes of the examined policy interventions on private trees because they had certain requirements for the number of trees per site. Table 4.2 Summary of indicators to measure for each policy intervention Indicator Type Indicator Name Explanation of Indicators Basic urban forest indicators # of trees Total number of trees Number of existing trees (trees that are retained since 2020) Number of replaced trees (trees that are planted to replace the removed or dead trees) Number of additional trees (trees that are planted in addition to the 1:1 replacement ratio) Tree canopy Canopy area of trees located on areas where the policy intervention is implemented (m2) Tree density Avg. number of trees per 100 m (for streets) OR Avg. number of trees per 100 m2 (for private parcels and parks) % of area covered by tree canopy Average % of private parcel/street/park covered by tree canopy 7 FAR: Floor Area Ratio, the ratio of the gross floor area of all buildings on a lot to the land area of the lot (Barr & Cohen, 2014) 80 Livability co-benefit indicators (the calculation includes the canopy of trees in other locations extended to the area of analysis) Highly treed street/ private parcels Number of highly treed streets (with >= 30% tree canopy cover) or highly treed private parcels (with >= 20% tree canopy cover) Access to urban forest canopy Number and % of residents with immediate access to highly treed streets (with >= 30% tree canopy cover) or parks (for streets and parks) OR Number and % of residents living in private parcels with >= 20% tree canopy cover (for private parcels) Number and % of residents with <= 5min access (i.e. within 400m) to highly treed streets (with >= 30% tree canopy cover) or parks (for streets and parks) Urban form/density indicators (for private parcels only) # of parcels with trees Number of parcels with at least 1 tree FAR Average FAR New development for parcels w/ new development only) Number and % of residents live on parcels with new developments 4.2.3 Acknowledgement of contribution The study used outcomes from other connected but independent projects, including the EEBE and UGUD projects. Specifically, the baseline and future sandbox models with urban form information were created by the EEBE project team without the author’s contribution. The author played a key role in developing the four different future urban forestry scenarios for the UGUD project and associated tree rules (the scenarios are different from the future policy interventions in Chapter 4). The author led the reviewing process of relevant policy documents in Vancouver, which was fundamental for developing tree rules (e.g., on tree mortality rate and tree spacing) for the future scenarios. 81 The policy interventions tested in Chapter 4 were developed based on the future urban forestry scenarios. The definition, selection, and evaluation (including the list of indicators and the analysis work) of the policy interventions in Chapter 4 were solely developed and completed by the author, under the guidance of her research committee. 4.3 Results Presented here are the projected outcomes of the different selected policy interventions on urban forest attributes and livability co-benefits for local residents in 2050. The section starts with an overview of the effects of individual policy interventions (Table 4.3), then a more detailed description of each intervention, and finally an analysis of the cumulative effects of all the moderate- and ambitious-effort interventions respectively and their connections with Vancouver’s urban forest canopy target, which is the major measurable urban forest target available for Vancouver currently (City of Vancouver & Vancouver Board of Parks and Recreation, 2018; Vancouver Board of Parks and Recreation, 2020). Table 4.3 provides a summary of the potential effects of each policy intervention, compared to the baseline conditions (2020). As expected, improvements in urban forest attributes (e.g., the number of trees and tree canopy area) and livability co-benefits were more significant under ambitious-effort interventions than with moderate-effort interventions. For example, with the development of a blue-green street network (ambitious-effort intervention), the number of trees on the streets selected for the blue-green street network was almost three times that of that of a 1.5x historical planting rate for street trees in the same area (moderate-effort intervention). The largest scale of increases in urban forest attributes was seen in the establishment of a new neighbourhood park (converted from a few commercial lots, ambitious-effort intervention), with over a 1,000% increase in the total number of trees (from 13 to 242), tree density (from 0.08 tree /100m2 to 1.4 trees/100m2), and the percentage of areas covered by tree canopy (from 4.1% to 77.3%) in the area where the new park was created. Even without the addition of a park, the moderate-effort intervention that 82 follows the current tree planting requirements in this area resulted in over 1,000% increases in the number of trees (from 13 to 168) and tree density (from 0.08 trees/100m2 to 0.97 trees/100m2). The scale of increases in livability co-benefits after implementing the policy interventions was generally more modest than the scale of changes in urban forest attributes. Most increases in livability co-benefits were under 100% with moderate-effort interventions and under 500% with ambitious-effort interventions. The largest increases in livability co-benefits were found with the creation of a blue-green street network. The number of highly treed street segments increased by 760%, from merely 5 streets in 2020 to 43 streets in 2050, thereby substantially improving people’s access to highly treed streets and street tree canopy, measured by the number of residents with immediate (0m) or easy (within 400m) access to highly treed areas. However, not all policy interventions led to improvements compared to the current condition. Surprisingly, there were 67% fewer highly treed parcels (i.e. with 20% or more tree canopy) compared to the baseline, even with the effort of planting at least one tree per parcel in 80% of the private parcels that did not have a tree (moderate-effort intervention). As a result, fewer people lived on highly treed parcels compared to the baseline. 83 Table 4.3 Summary of the projected effects on urban forest attributes and livability co-benefits of selected policy interventions Table cells were coloured based on the percentage of change from the baseline in 2020 (see colour code below). The percentage of change was based on the area where each policy intervention was applied. NA -100% to -1% 0% 1% to 100% 101% to 200% 201% to 500% 501% to 1000% 1001%+ /// PRIVATE JURISDICTION: DEVELOPMENT RELATED PUBLIC JURISDICTION: INFRASTRUCTURE RELATED PRIVATE TREES: COMPLIANCE W/ TREE PLANTING RQMTS PRIVATE TREES: VARIED PLANTING REQUIREMENTS STREET TREES: VARIED PLANTING REQUIREMENTS STREET TREES: BLUE-GREEN STREET NETWORK PARK TREES: NEW NEIGHBOURHOOD PARK PARK TREES: VARIED PARK DESIGNS Applied Spatial Scale Redeveloped Parcels Parcels with No Redevelopment All Street Segments 49 Selected Street Segments A Selected Area (Zoned for Commercial Use in Baseline) A Selected Park Effect of Policy Interventions Moderate: Compliance w/ Tree Planting Rqmt (2050) Moderate: 80% of Parcels w/ Min. 1 Tree (2050 Ambitious: 99% of Parcels w/ Min. 2 Trees (2050) Moderate: Planting at 1.5x Historical Rate (2050) Ambitious: Planting at 3x Historical Rate (2050) Moderate: Planting at 1.5x Historical Rate (2050) Ambitious: Blue-Green Street Network (2050) Moderate: Compliance w/ Tree Planting Rqmt (2050) Ambitious: New N'hood Park (2050) Moderate: Planting of 2 Rows of Park Trees (2050) Ambitious: Planting of Tree Groves (2050) Urban Forest Indicators # of trees Total # of trees Tree canopy Tree canopy (m2) Tree density Avg. # of trees per 100 m or per 100 m2 Livability Co-benefit Indicators % of area covered by tree canopy Avg. % of area covered by tree canopy Highly treed street/parcel* # of highly treed streets/parcels* Access to urban tree canopy # of residents with immediate access** # of residents with <= 5min access * Highly treed parcels measured in parcels with 20% tree canopy * Highly treed streets measured in streets with 30% tree canopy cover ** Immediate access measured in residential parcels right by the selected park ** immediate access measured in private home residence with >=20% tree canopy cover ** Immediate access measured in residential parcels right by highly treed streets (>=30% tree canopy cover) 84 4.3.1 Private jurisdiction: development-related urban forestry policy interventions 4.3.1.1 Private trees: compliance with current tree planting requirements The section summarizes the potential effects in 2050 of compliance with current requirements on the number of trees per site outlined in Vancouver’s Tree Protection Bylaw by redevelopment projects, without allowing for cash-in-lieu of planting/retaining or similar alternatives (City of Vancouver, 2022d). The policy intervention tested here was based on the assumption that redevelopment projects could provide opportunities for more tree-friendly designs (Chapter 3), allowing these private parcels to meet the tree number requirements by 2050. The analysis focused on 570 private parcels within the sandbox that were redeveloped by 2050 (a total area of 264,778 m2, 10% of the study area) (Figure 4.6). After redevelopment, the FAR of these 570 parcels increased from 0.61 to 0.78, and the number of residents increased by 40%, from 2,232 in 2020 to 3108 in 2050. According to the tree number requirements specified by Vancouver’s tree by-law (City of Vancouver, 2022d), all parcels should have at least two trees per parcel, given their sizes (range from 358 m2 to 6,800 m2), well beyond the number of trees present on the 570 parcels in the baseline (currently 445 out of the 570 parcels do not have any trees on site). 85 Figure 4.6 Private trees on redeveloped parcels (a) in 2020 (the baseline) and (b) in 2050 where current tree planting requirements are implemented. The inserts are samples of detailed views from the total interventions. As indicated in Table 4.4, despite an increase in density, urban forest attributes, especially the total number of trees and tree density, increased considerably by approximately 1,000% from the baseline. By complying with the requirements for the number of trees, residents could have a higher tree cover on their property. The average percentage of area covered by tree canopy increased five times, from 2.6% to 11.7%. However, the number of highly treed parcels and the number of residents living on these parcels increased moderately by no more than 20%. 86 Table 4.4 Summary of the urban forest and livability co-benefit indicators of the redeveloped parcels in the baseline (2020) and after compliance with current tree planting requirements (2050) The percentages in brackets indicate the levels of change since the baseline (2020). Colour legend: -100% to -1% 0% 1% to 100% 101% to 200% 201% to 500%\\\ \\\501% to 1000% 1001%+ / Effect of policy interventions on the redeveloped parcels (570 parcels) Baseline (2020) Compliance w/ Tree Number Requirements (Moderate Effort, 2050) Urban forest indicators # of trees Total # of trees 179 1,927 (+977%) # of existing trees - 3 # of replaced trees - 182 # of additional trees - 1742 Tree canopy Tree canopy of areas where the policy intervention is implemented (m2) 6,775 2,9617.38 (+337%) Tree density Avg. # of trees per 100 m2 0.066 0.78 (+1082%) Livability co-benefit indicators Tree canopy cover % Average % of private parcel covered by tree canopy 2.6% 11.7% (+445%) Highly treed parcels # of parcels with >= 20% tree canopy 10 12 (+20%) Access to urban forest canopy # and % of residents live in a parcel with >= 20% tree canopy 34, 0.6% 37 (+9%), 0.2% Urban density indicators # of parcels with trees # of parcels with at least one tree 125 570 (+356%) FAR Average FAR 0.61 0.78 (+28%) 87 Effect of policy interventions on the redeveloped parcels (570 parcels) Baseline (2020) Compliance w/ Tree Number Requirements (Moderate Effort, 2050) New development # and % of residents on parcels with new developments 2,232, 14.7% 3,108 (+39%), 15.2% 4.3.1.2 Private trees: varied planting requirements Two different policy interventions to increase the minimum number of trees on private land were evaluated: 1) plant at least one tree on 80% of private parcels without trees (Figure 4.7.b), and 2) ensure 99% of private parcels have at least 2 trees on site (Figure 4.7.c). The analysis focused on 2,896 private parcels without any redevelopment from 2020 to 2050 (1,198,182 m2, 46% of the study area). Some parcels had small renovations to increase floor area to accommodate a growing population in this area (from 12,300 in 2020 to 12,833 in 2050, 4% increase), resulting in a slight increase in FAR from 0.58 to 0.66 (14% increase). 88 Figure 4.7 Private trees on parcels with no redevelopment (a) in the baseline (2020), (b) with a moderate-effort intervention to ensure 80% of private parcels have at least 1 tree in 2050, and (c) with an ambitious-effort intervention where 99% of private parcels have at least 2 trees on site in 2050. Both policy interventions boosted the number of trees and tree density of private parcels by approximately three times or more. However, as mentioned earlier, the scales of changes with the application of moderate-effort interventions (i.e., planting min. 1 tree on 80% of treeless private parcels) were much more modest than those with ambitious-effort interventions (i.e., ensuring 99% of private parcels have min. 2 trees). 89 Overall, the average percentage of area (of analysis) covered by tree canopy increased, from 2.7% in 2020 to 4.6% with moderate-effort intervention in 2050 (70% increase) and 12.2% with ambitious-effort intervention in 2050 (352% increase). However, the number of highly treed parcels was reduced by 67% with the moderate-effort intervention. As a result, the number of residents living on these highly treed parcels reduced by 90% from the baseline. Moreover, although the number of highly treed parcels after applying the ambitious-effort intervention increased by 72% from the baseline, the number of residents living on these highly treed parcels reduced by 42% (or 243 people). These reductions in the number of highly treed parcels and/or the number of residents living on these parcels were possibly due to the loss of large mature trees from the baseline in 2020, especially on the two low-rise residential parcels at the top right corner with over 300 residents (Figure 4.7). Further analysis of the aged-out trees from the baseline and replacement trees in 2050 was conducted to understand the decrease in the number of highly treed parcels despite an increased planting effort. Taking the moderate-effort intervention as an example, regardless of the 1:1 tree replacement rule, the 626 replaced trees planted in 2050 (9,434 m2 of tree canopy) could merely make up 38% of the lost canopy cover due to the removals of 579 “aged-out” trees (24,603 m2 of canopy cover). Although planting replaced and additional trees helped increase the total tree canopy, the loss of large mature trees from the baseline (average crown diameter is 7 metres, compared to 4 metres for replaced trees) led to the reduced number of highly treed parcels in 2050. 90 Table 4.5 Summary of the urban forest and livability indicators of the private parcels with no redevelopment in the baseline (2020), after applying the moderate-effort intervention to ensure 80% of the analyzed parcels have minimally 1 tree (2050), and after applying the ambitious-effort intervention where 99% of analyzed parcels have minimally 2 trees (2050). The percentages in brackets indicate the levels of changes since the baseline (2020). Colour legend: -100% to -1% 0% 1% to 100% 101% to 200% 201% to 500%\\\ \\\501% to 1000% 1001%+ / Effect of policy interventions on private parcels with no redevelopment (2,896 parcels) Baseline (2020) Min.1 Tree for 80% of Private Parcels (2050) Min. 2 Trees for 99% of Parcels (2050) Urban forest indicators # of trees Total # of trees 841 3,147 (+274%) 5,948 (+607%) # of existing trees - 239 327 # of replaced trees - 626 483 # of additional trees - 2282 5138 Tree canopy Tree canopy of areas where the policy intervention is implemented (m2) 32,397 50,025 (+54%) 121,440 (+275%) Tree density Avg. # of trees per 100 m2 0.064 0.27 (+322%) 0.56 (+775%) Livability co-benefit indicators Tree canopy cover % Average % of private parcel covered by tree canopy 2.7% 4.6% (+70%) 12.2% (+352%) Highly treed parcels # of parcels with >= 20% tree canopy 43 14 (-67%) 74 (+72%) Access to urban forest canopy # and % of residents live on a parcel with >= 20% tree canopy 501, 3% 50 (-90%), 0.2% 293 (-42%), 1% 91 Effect of policy interventions on private parcels with no redevelopment (2,896 parcels) Baseline (2020) Min.1 Tree for 80% of Private Parcels (2050) Min. 2 Trees for 99% of Parcels (2050) Urban density indicators # of parcels with trees # of parcels with at least one tree 599 2,504 (+318%) 2,896 (+383%) FAR Average FAR 0.58 0.66 (+14%) 0.66 (+14%) 4.3.2 Public jurisdiction: infrastructure-related greening policy interventions 4.3.2.1 Street trees: varied planting requirements The section summarizes the projected urban forest and livability co-benefit outcomes of policy interventions with different planting rates, i.e., planting street trees at 1.5x or 3x of historical rate, compared to the number of street trees planted in the past 30 years in Vancouver (City of Vancouver & Vancouver Board of Parks and Recreation, 2018). A total of 267 street segments (including a blue-green street network explained in 3.2.2) were included in the analysis (a total area of 618,077 m2, 24% of the study area) (Figure 4.8). Figure 4.8 Street trees (a) in the baseline (2020), (b) after applying the moderate-effort intervention with a 1.5x historical planting rate in 2050, and (c) after applying the ambitious-effort intervention with a 3x historical rate of planting street trees in 2050. 92 Urban forest attributes were enhanced (e.g., the number of trees and street tree density) with the higher (1.5x or 3x) planting rates. However, the changes were modest. The scales of increases were within 100% with the moderate-effort intervention and within 200% with the ambitious-effort intervention. For example, the street tree canopy area was increased by merely 6% from the baseline with the moderate-effort intervention. Despite the relatively modest increases, more residents had improved access to more street trees and their associated benefits after adopting both policy interventions. On average, 26% of the street area was covered by tree canopy in 2050 with the ambitious-effort intervention (98% increase since 2020), and 17% of tree canopy cover was achieved with the moderate-effort intervention (35% increase since 2020). Interestingly, there was no change in the number of highly treed streets after planting street trees 1.5 times faster compared to the baseline. However, the percentage of residents (out of the total population in the study area) living by or within 400 metres of the highly treed streets was reduced due to the uneven spatial distribution of the highly treed streets in 2050 (Figure 4.9). Table 4.6 Summary of the urban forest and livability indicators of all street segments in the baseline (2020), with a 1.5x historical planting rate (2050), and with a 3x historical planting rate (2050) The percentages in brackets indicate the levels of changes since the baseline (2020). Colour legend: -100% to -1% 0% 1% to 100% 101% to 200% 201% to 500%\\\ \\\501% to 1000% 1001%+ / Effect of policy interventions of all street segments (267 street segments) Baseline (2020) 1.5x Historical Planting Rate (2050) 3x Historical Planting Rate (2050) Urban forest indicators # of trees Total # of trees 2,542 4,054 (+59%) 5,830 (+129%) # of existing trees - 1,153 1,566 93 Effect of policy interventions of all street segments (267 street segments) Baseline (2020) 1.5x Historical Planting Rate (2050) 3x Historical Planting Rate (2050) # of replaced trees - 1,389 976 # of additional trees - 1,512 3,288 Tree canopy Tree canopy of areas where the policy intervention is implemented (m2) 101,224 107,766 (+6%) 167,016 (+65%) Tree density Avg. # of trees per 100m 7 14 (+100%) 20 (+181%) Livability co-benefit indicators % of street covered by tree canopy Average % of street segment covered by tree canopy 12.9% 17.4% (+35%) 25.6% (+98%) Highly treed street # of streets with >= 30% tree canopy 26 26 74 (+185%) Access to urban tree canopy # and % of residents with immediate access to highly treed street segments 2,389, 16% 2,831 (+19%), 14% 5,098 (+113%), 58% # and % of residents with <= 5min access to highly treed street segments (i.e. within 400m) 14,927, 98% 17,133 (+15%), 82% 20,389 (+37%), 100% 94 Figure 4.9 Location of highly treed streets and parcels within 400m (Euclidean distance) of these highly treed streets (a) in the baseline (2020), (b) with a 1.5x historical street tree planting rate (2050), and (c) with a 3x historical street tree planting rate (2050). 4.3.2.2 Street trees: blue-green street network This section presents the potential effects of implementing a blue-green street network policy (ambitious effort) and planting street trees at 1.5x historical rate (moderate effort) in 2050, compared to the baseline in 2020. The analysis focused on 49 street segments 95 that were converted into blue-green streets in 2050 (a total area of 104,689 m2, 17% of street space and 4% of the study area). Figure 4.10 illustrates the location of these 49 selected streets and changes in the tree canopy of these streets from 2020 to 2050. Figure 4.10 Street trees on the selected 49 street segments (a) in the baseline (2020), (b) with the moderate-effort intervention to plant street trees at 1.5x historical rate (2050) and (c) with the ambitious-effort intervention to create a blue-green street network (2050). The inserts are samples of detailed view from the total interventions. With the implementation of blue-green street network policy, most urban forest attributes within the 49 street segments, such as the total number of trees and tree canopy area, were doubled or tripled compared to the 2020 baseline. The only exception was the tree density, with a more moderate (119%) increase since 2020. Comparatively, the increases resulting from the moderate-effort intervention (1.5x planting rate) were much more limited (usually below 100%) (Table 4.7). Residents had better access to more street trees with the implementation of both policy interventions (especially with the creation of the blue-green street network). The number of highly treed streets and the number of residents with immediate access to these 96 streets increased by over 700% since 2020 after the blue-green streets were created, while the increases with 1.5x planting rate were not more than 100%. 77% (15,747) of residents lived within 400 metres from the highly treed streets with a 1.5x planting rate, a 50% increase from the baseline. With the implementation of a blue-green street network policy, the percentage of residents living within 400 metres of the highly treed streets increased to 98% (19,952 residents), a 91% increase from the baseline (Figure 4.11). Table 4.7 Summary of the urban forest and livability co-benefit indicators of the selected 49 street segments in the baseline (2020), after planting street trees at 1.5x historical rate (2050), and after creating a blue-green street network (2050) The percentages in brackets indicate the levels of changes since the baseline (2020). Colour legend: -100% to -1% 0% 1% to 100% 101% to 200% 201% to 500%\\\ \\\501% to 1000% 1001%+ / Effect of policy interventions on the selected 49 street segments Baseline (2020) 1.5x Historical Planting Rate (2050) Blue-Green Street Network (2050) Urban forest indicators # of trees Total # of trees 394 676 (+72%) 1,811 (+360%) # of existing trees - 179 249 # of replaced trees - 209 142 # of additional trees - 288 1420 Tree canopy Tree canopy of areas where the policy intervention is implemented (m2) 14,869 19,343 (+30%) 50,462 (+239%) Tree density Avg. # of trees per 100m 21 23 (+10%) 46 (+119%) Livability co-benefit indicators % of street covered by Average % of street segment covered by tree canopy 12.9% 19.4% (+50%) 44.9% (248%) 97 Effect of policy interventions on the selected 49 street segments Baseline (2020) 1.5x Historical Planting Rate (2050) Blue-Green Street Network (2050) tree canopy Highly treed street # of streets with >= 30% tree canopy 5 10 (+100%) 43 (+760%) Access to urban tree canopy # and % of residents with immediate access to highly treed street segments 336, 2.2% 530 (+58%), 2.6% 2,947 (+776%), 14.5% # and % of residents with <= 5min access to highly treed street segments (i.e. within 400m) 10,469, 69% 15,747 (+50%), 77% 19,952 (+91%), 98% 98 Figure 4.11 Location of highly treed blue-green streets and parcels within 400m (Euclidean distance) of these highly treed streets (a) in the baseline (2020), (b) with a 1.5x historical street tree planting rate (2050), and (c) with a blue-green street policy (2050). 4.3.2.3 Park trees: new neighbourhood park This section compares two policy interventions that could be applied to an area of 17,271 m2 (0.7% of the study area, currently zoned for commercial use only). The moderate-effort intervention was to enforce on the commercial lots the current requirements on the number of trees per site outlined in Vancouver’s Tree Protection Bylaw, without allowing for cash-in-lieu of planting/retaining or similar alternatives. The 99 ambitious-effort intervention was to convert these commercial lots into a new neighbourhood park with over 70% tree canopy cover. In order to create a new park while providing a similar number of commercial units, the area had to be further densified. As illustrated in Figure 4.12, additional buildings were added when a new park was created. Figure 4.12 Maps of the commercial area selected for a new neighbourhood park and the land use details of parcels surrounding the selected area (a) in the baseline (2020), (b) after complying with the current planting requirements (2050), and (c) after creating a new neighbourhood park (2050). The inserts are areas where the policy interventions were applied. The total number of trees and tree density was increased by over 10 times from the baseline with the implementation of both policy interventions. This was especially the case with creating a new neighbourhood park. This is the only set of policy interventions that achieved over 1,000% increases in urban forest attributes for both moderate and ambitious efforts. However, the ample increase in the number of trees didn’t translate into a similar scale increase in tree canopy for the moderate intervention (i.e., compliance with the requirements on the number of trees per site). The increase in tree canopy area from the baseline as a result of the moderate-effort intervention was at 100 123%, much smaller compared to the increase achieved in the number of trees (over 1000%). Adding a neighbourhood park in the park-deficit northeastern corner of the study area improved people’s access to parks and park trees (Figure 4.13). 457 residents (2% of the total) gained immediate access to a park that they would not have before because they lived right next to the new park. In addition, adding a new park could allow about 7,600 more people (a total of 17,639 residents, 87% of the total) to live within 400 metres of a park, compared to the baseline (Figure 4.13). Table 4.8 Summary of the urban forest and livability co-benefit indicators of the areas selected for a new park in the baseline (2020), after complying with current requirements on the number of trees per site (2050), and after creating a new neighbourhood park (2050) The percentages in brackets indicate the levels of changes since the baseline (2020). Colour legend: -100% to -1% 0% 1% to 100% 101% to 200% 201% to 500%\\\ \\\501% to 1000% 1001%+ / Effect of policy interventions on the area selected for a new park in 2050 Baseline (2020) Compliance w/ Planting Require- ments (2050) New Neighbour-hood Park (2050) Urban forest indicators # of trees Total # of trees 13 168 (+1192%) 242 (+1762%) # of existing trees - 0 5 # of replaced trees - 23 8 # of additional trees - 145 229 Tree canopy Tree canopy of areas where the policy intervention is implemented (m2) 1013 2,264 (+123%) 10,222 (+909%) 101 Effect of policy interventions on the area selected for a new park in 2050 Baseline (2020) Compliance w/ Planting Require- ments (2050) New Neighbour-hood Park (2050) Tree density Avg. # of trees per 100 m2 0.08 0.97 (+1192%) 1.40 (+1762%) Livability co-benefit indicators % of area covered by tree canopy % of park area covered by tree canopy 4.1% 14.2% (+246%) 77.3% (+1785%) Access to urban tree canopy # and % of residents with immediate access to the new park - - 457, 2.2% # and % of residents with <= 5min access to a park (i.e. within 400m) 10,063, 66% 12,576 (+25%), 62% 17,639 (+75%), 87% 102 Figure 4.13 Location of parks, park trees, and parcels within 400m (Euclidean distance) of parks (a) in the baseline (2020), (b) after the current planting requirements are enforced (2050), and (c) after creating a new neighbourhood park (2050). 4.3.2.4 Park trees: varied park designs The section focused on the potential effects of implementing two different park designs and tree planting approaches: a moderate-effort approach of planting trees along park boundary (Figure 4.14, b) and a ambitious-effort approach of planting groves of trees within a park to achieve an over 50% forest canopy cover (Figure 4.14, c). 103 Figure 4.14 The selected park (a) in the baseline (2020), (b) with the moderate-effort intervention that plants 2 rows of trees along park boundary (2050) and (c) with the ambitious-effort intervention that plants groves of trees (2050). The inserts are samples of detailed view from the total interventions. Both policy interventions led to improvements in urban forest attributes but not in access-related livability co-benefits. The implementation of the moderate-effort intervention (planting 2 rows of park trees) increased the number of park trees and tree density by 31% from the baseline. In the case of applying the ambitious-effort policy intervention (foresting a park), the increase was much more substantial, 228% for both the number of park trees and tree density. As a result, the area of tree canopy increased by 41% (with the moderate-effort intervention) and 161% (with the ambitious-effort intervention) respectively. Because no change was made to the number, size or location of any park, there was no change in people’s access to parks. However, due to different park designs and planting approaches, people could have access to different levels of park tree canopy, from 20% in baseline to 28% (with moderate-effort intervention) or 53% (with ambitious-effort intervention) in 2050, and associated ecosystem benefits provided by park trees. 104 Table 4.9 Summary of the measured urban forest and livability outcomes of the selected park in the baseline (2020), after applying the moderate-effort intervention that plants 2 rows trees along park boundary (2050), and the ambitious-effort intervention that plants groves of trees in the park (2050) The percentages in brackets indicate the levels of changes since the baseline (2020). Colour legend: -100% to -1% 0% 1% to 100% 101% to 200% 201% to 500%\\\ \\\501% to 1000% 1001%+ / Effect of policy interventions on a selected park Baseline (2020) Planting 2 Rows of Trees Along Park Boundary Rate (2050) Planting Groves of Trees within A Park (2050) Urban forest indicators # of trees Total # of trees 241 315 (+31%) 790 (+228%) # of existing trees - 108 155 # of replaced trees - 207 87 # of additional trees - 0 548 Tree canopy Tree canopy of areas where the policy intervention is implemented (m2) 13,764 19,463 (+41%) 35,886 (+161%) Tree density Avg. # of trees per 100 m2 0.35 0.46 (+31%) 1.55 (+228%) Livability co-benefit indicators % of area covered by tree canopy % of park area covered by tree canopy 20.3% 27.5% (+35%) 52.7% (+159%) Access to urban tree canopy # and % of residents with immediate access to the park 258 269 (+4%) 269 (+4%) # and % of residents with <= 5min access to a 2,808, 19% 2,928 (+4%), 14% 2,928 (+4%), 14% 105 Effect of policy interventions on a selected park Baseline (2020) Planting 2 Rows of Trees Along Park Boundary Rate (2050) Planting Groves of Trees within A Park (2050) park (i.e. within 400m) 4.3.3 Alignment with Vancouver’s current tree canopy target To illustrate a key measure of the cumulative effectiveness of these policy interventions, overall tree canopy results of the moderate and aggressive interventions were compared to the City of Vancouver’s 30% tree canopy target to be achieved by 2050 respectively. Scaling the city-wide target down to the study site, 779,551 m2 of tree canopy (30% of the study area) is needed to achieve this target. Overall, ambitious-effort policy interventions, if implemented together, could contribute almost half of the site-scale 30% tree canopy target (49%, 378,916 m2), while the moderate-effort interventions could contribute up to 29% (223,868 m2, 59% of what could be achieved with ambitious-effort interventions) (see Figure 4.15 and Table 4.10 for details). Figure 4.15 Tree canopy cover and locations after applying all the moderate- and ambitious-effort interventions. 106 Increasing planting rates of street trees neighbourhood-wide seemed the most effective in helping achieve the 30% target within the sandbox. Planting 3x the number of street trees relative to the number of street trees planted in the past 30 years in Vancouver (one of the ambitious-effort interventions) could make a 21.4% contribution to meeting the site-scale canopy target, which was the highest among all. Planting street trees at 1.5x historical rate was also the top contributor among the moderate-effort interventions. Increasing planting requirements on private parcels came in second. The ambitious-effort intervention that required 99% of private parcel to have at least 2 trees contributed 15.6% to reaching the canopy target. These two policy interventions on private and street planting were more effective than the others, partially due to the large area where they were implemented – street area accounted for 23.8% of the study area and the private parcels with increased planting requirements accounted for 46.1% of the study area. Given the differences in private, street, and park area, a further analysis was carried out on the contribution of each policy intervention to the site-scale 30% canopy target, standardized to the area where each intervention was applied (Figure 4.16). Park-related policy interventions (e.g., creating a new park) had the highest standardized percentage contribution (up to 197.3% for the ambitious-effort ones). However, they had a limited role in achieving the 30% canopy target of the sandbox, with the actual percentage contributions ranging from 0.3% to 4.6%. A similar pattern was found for the blue-green street network policy interventions — it could contribute only 6.5% to achieving the site-scale 30% canopy target because of the small area where this policy intervention was applied (4% of the study area). 107 Figure 4.16 Absolute (a) and standardized (b) percentage of contribution each policy intervention made to achieving the 30% tree canopy target within the sandbox (i.e. 779,551 m2 of tree canopy in the study area) The contribution of each policy intervention was standardized to the size of the area where it was implemented in figure (b). Table 4.10 Tree canopy area as a result of implementing the selected urban forestry policy interventions and their contribution (in percentage) to achieving the 30% tree canopy target in the sandbox area BASELINE MODERATE-EFFORT INTERVENTIONS AMBITIOUS-EFFORT INTERVENTIONS Policy interventions Canopy area (m2) Contribution to the site-scale 30% target Canopy area (m2) Contribution to the 30% target Canopy area (m2) Contribution to the 30% target PRIVATE TREES: Compliance w/ tree 6,774.7 0.9% 44,350.3 3.8% - - 108 planting requirements PRIVATE TREES: Varied planting requirements 32,396.6 4.2% 50,024.7 6.4% 121,440.4 15.6% STREET TREES: Blue-green street network 14,869.3 1.9% 19,343.4 2.5% 50,462.0 6.5% STREET TREES: Varied planting requirements 101,224.0 13.0% 107,765.6 13.8% 167,016.4 21.4% PARK TREES: New n’hood park 1,013.4 0.1% 2,264.1 0.3% 10,222.2 1.3% PARK TREES: Varied park designs 13,763.9 1.8% 19,463.4 2.5% 35,886.4 4.6% 4.4 Discussion 4.4.1 Urban forestry policy interventions for a walkable, green, and resilient city The study identified and examined 6 sets of policy interventions (11 in total) that cities could implement to enhance urban forests in private, street, and park space despite densification and climate change. Regardless of the level of effort (moderate or ambitious), we found improvements in urban forest attributes and livability co-benefits for most of the policy interventions. For example, the conversion of commercial lots into a new neighbourhood park (an ambitious-effort intervention) achieved the greatest increase (over 1,000%) in urban forest attributes within the area of application. The only exception to positive outcomes were policy interventions with private tree planting requirements. The number of highly treed parcels and the number of residents 109 with easy access to these parcels from their homes were reduced from the baseline, even after applying an increased planting requirement for private trees, likely due to the loss of large mature trees and the planting of smaller replacement trees. Taken together, ambitious-effort interventions lead to larger scales of improvements than moderate-effort interventions. The combined effects of all the tested ambitious-effort interventions would contribute to merely half (49% to be exact) of meeting 30% tree canopy in the study site, while the moderate-effort interventions would contribute to 29% of the canopy target. Among the interventions, enhancing street tree and private tree planting requirements seemed to be the most effective in helping the city achieve the 30% tree canopy target, whereas park-related interventions made the smallest contribution (1.3% to 4.6%) to achieving the target. These findings highlight the urgent need for cities like Vancouver to strategically integrate urban forest planning in the early stages of urban planning processes (especially road renewal planning) and to substantially strengthen the tree protection and planting requirements if the 30% tree canopy target is to be achieved. 4.4.2 Important implications for establishing and managing urban forests Planting on existing green spaces is not enough The findings of this study clearly showed that cities like Vancouver need to drastically enhance their tree planting and management requirements on both private and public land, in order to fulfill their urban forestry targets, which is in line with previous studies (Brunner & Cozens, 2013; Galvin et al., 2006; Troy et al., 2007). Although significant increases were found by planting trees in parks or creating a new park, planting park trees alone would not be enough. This is due to the small ratio of park area to total land area. Within the study area, creating a new park of 17,271 m2 with over 70% tree canopy cover would contribute only 1.3% to meeting the 30% tree canopy in the study site (which aligns with the current city-wide target in Vancouver). Turning a park into a forest park with over 50% tree canopy could contribute 4.6%. Scaling up to the whole city, focusing on parks alone would require over 20 such new parks, and in a dense and densifying city like Vancouver, many such land reallocations are unlikely to be feasible. 110 Integrating green equity into planning and managing urban forests is important Previous studies have demonstrated why planting in easy spots, such as parks with large pervious surfaces and open space for trees, would not be enough in reaching the tree canopy and other urban forestry-related targets (Garrison, 2019). A major concern related to this practice is about distributional equity of urban forests. For example, New York City’s Million Tree Campaign planted 83% of its trees in parks. This caused a great deal of discussions and concerns that it could further reinforce inequitable access to urban forests and parks, since these parks were not equitably distributed to begin with (Garrison, 2019). The importance of equitable distribution of urban forests and other publicly accessible green spaces was also verified by the findings of this study. In the analysis of the street greening policy intervention, while the number of highly treed streets remained the same from the 2020 baseline after applying 1.5 times the historical street tree planting rate, the percentage of residents with both immediate (0m) and easy access (within 400m) decreased due to a more uneven distribution of the highly treed streets (Figure 4.9). Having access to publicly available green spaces and trees is especially crucial in an underserved community as it can help alleviate the gaps in essential services and resources provided by urban vegetation (usually health associated) between privileged groups and people with lower social-economic backgrounds (Garrison, 2019; Nesbitt et al., 2019). Cities should integrate equity thinking in the early stages of planning to avoid reinforcing existing inequities as a result of urban development and tree planting history. Retaining large mature trees is of more critical importance than just planting new trees The findings of this study also highlight the importance of retaining large mature trees, rather than prioritizing planting new trees as compensation, which aligns with previous studies on large-scale planting programs such as million-tree-planting campaigns (Garrison, 2019). Our study showed that without adequately retaining existing mature trees, it was still possible to have a declining tree canopy despite the effort to plant a 111 substantial number of trees. After almost tripling the number of trees with an increased planting requirement for private trees, the number of highly treed parcels was reduced from 43 in 2020 to only 14 in 2050, as indicated in Table 4.5, mainly due to the loss of large mature trees. Trees can provide maximized ecological, social and economic benefits when they are healthy and mature (Chi et al., 2022; Turner-Skoff & Cavender, 2019; Vogt et al., 2015). If a mature tree is removed, these lost benefits are difficult to make up by planting small young trees that are yet to yield more benefits than costs (e.g., costs of purchasing and watering trees). Cities need to prioritize both sets of policies at once, so that retained mature trees can ‘buy time’ for maturing young trees and avoid damaging loss of ecosystem services over the short and medium term. Our analysis on varied street tree planning requirements also indicated that retaining large mature trees has important implications for maintaining or enhancing equitable distribution of urban forests. Even with a 1.5x street tree planting rate, the southwest corner of the sandbox area lost a number of highly treed streets due to the loss of large mature trees from the baseline (Figure 4.9), resulting in more inequitable access to highly treed streets among residents. In addition, the maintenance of newly planted trees is equally important, especially during the early survival and establishment stages (Vogt et al., 2015). Studies have shown that the survival rates of the early establishment stages are crucial to gaining cumulative benefits from trees in their later growth stages. A lower survival rate could lead to a net loss of benefits, considering the maintenance costs, as the annual increase in tree benefits could no longer offset the lost benefits due to tree decline, mortality and removal (Turner-Skoff & Cavender, 2019). This is particularly crucial for rapidly developing cities to consider in planning new development or redevelopment projects where mature trees are often removed due to policy trade-offs (as identified in Chapter 3) and replaced with small young trees. Integrative thinking of the holistic urban forest system is needed 112 Park, private and street trees are integral parts of the urban forest system. Park trees are essential elements in forming urban green hubs, providing numerous ecological, socio-cultural and recreational values to local residents. Private trees provide residents with immediate access to these mentioned benefits from home (e.g., shade provision and aesthetic values) (Conway, 2016; D. L. Erickson, 2006b). Street trees are important for creating safe, desirable and comfortable pathways connecting residents’ destinations (e.g., homes and parks) (Church, 2018). They are particularly crucial in enhancing people's access to trees and associated benefits in areas where private trees were lacking. Although increasing street tree planting rates seemed to be the most effective approach overall in achieving the 30% tree canopy target according to the results, it is important to consider planting opportunities on land for other uses (e.g., residential housing and parks). Adapting from the taxonomy of landscape ecology, Figure 4.17 illustrates the connections of park (hub), street (link), and private (site) trees as fundamental parts of the urban forest system (D. L. Erickson, 2006a). Figure 4.17 An urban forest system comprised of park trees (hubs), street trees (links), and private trees (sites) based on landscape ecology theory The figure was adapted from Figure 1.6 by D. L. Erickson (2006, p. 18). 113 Public engagement and stewardship is crucial Adopting holistic views of the urban forest system also reveals the importance of improved education, engagement and stewardship of citizens and other key stakeholders beyond the municipal departments that have sole authority over trees within public jurisdiction. In many North American cities, the majority of urban trees are located on private properties, highlighting the importance of and need for engaging and collaborating with private property owners on private tree planting and management (Conway, 2016; Croeser et al., 2020). Trees on public land, such as streets and parks, also require citizen stewards as most cities do not have sufficient staff members and funds to closely care for individual trees (Pincetl et al., 2013). There are some successful examples of engagement programs, such as adopt-a-tree program and tree planting volunteer programs (Collaborative for Advanced Landscape Planning (CALP), n.d.; Local Enhancement & Appreciation of Forests (LEAF), n.d.), to encourage residents and other non-government stakeholders to get more involved in urban tree planting and management processes (Dowell, 2017; Ordóñez & Duinker, 2013). However, the status quo on community engagement is not adequate to sustain and build a healthy urban forest. Several studies have reported the lack of proper understanding of urban forests among key stakeholders, such as local residents and municipal staff (see examples from Chapter 3, Clark et al., 2020) and limited engagement of non-municipal-government stakeholders in urban forestry policy making, implementation processes, and stewardship (Cheng et al., 2021). 4.4.3 Limitations and directions of future research There are several limitations to this study which could suggest directions for future research on related topics. First, the future projections of this study were based on pre-set tree rules in 2050, such as assumed mortality rates, tree sizes, and tree spacing (summarized in Appendix C.1). In real life, these pre-set rules are not likely to be rigorously followed. Therefore, the findings of this study (e.g., tree canopy area, and the total number of trees) should be considered estimates based on these assumptions. Future studies should consider using dynamic forecasting of tree growth, rather than 114 static sets of rules (e.g., trees in 2050 are 80% of their mature size), to more accurately capture the growth over time. In addition, the replaced and additional tree species tended to be smaller trees, chosen for their climate adaptability (e.g. against wind storms) and space limitations. The selection of smaller tree species may have led to a lower estimate of tree canopy and other tree attributes in 2050. Having those rules set due to scope limitations also means that this study was unable to test the effects of any variation in these pre-decided factors (e.g., a high vs. low tree mortality rate) on urban forest attributes and livability co-benefits. Mortality rates, tree species selection, and tree spacing are crucial factors to consider for on-the-ground implementation. Therefore, future research should explore sensitivity testing of different planting and management decisions that lead to variations in these factors (e.g., mortality rates and tree species) and their short- and long-term implications for urban forests. Due to the nature of scenario planning methods, the study investigated a limited number of plausible policy interventions (Hilde & Paterson, 2014). More research could be done to explore other possible urban forestry policy interventions (or more ambitious interventions, such as greening currently underutilized space (e.g., laneways and roundabouts of quieter streets) and making most streets blue-green streets with 4 rows of street trees) that cities could consider during densification processes. In addition, due to the scope limitation, the study did not investigate the effects on trees of potential conflicts between trees and grey infrastructure, such as underground utilities and parking. Previous research has pointed out that grey infrastructure, such as buildings, underground utilities, and sidewalks, can significantly limit the growing space for trees and even lead to tree removals (Guo et al., 2019; Haaland & Konijnendijk van den Bosch, 2015). Future studies should delve into the conflicts between various site-scale factors, such as between existing grey infrastructure and trees and potential solutions to resolve them, especially for the most aggressive ambitious-effort interventions that would require drastic policy changes and innovative designs and practices (e.g., the intervention of creating a blue-green street network with 4 rows of street trees). Furthermore, the study did not analyze the possible interactions among trees, associated ecological factors (e.g., soils and other vegetation), and urban structures, 115 which would extremely useful for providing meaningful suggestions on site-scale designs and implementation. Future studies could consider developing three-dimensional cross sections that visualize these interactions to provide useful insights into site designs to support better tree survival results and healthier tree growth. Due to data limitations, this study heavily relied on measures of tree canopy cover and the number of trees, which are not sufficient to fully reflect the conditions of urban forests and the benefits that they provide. While tree canopy cover is a commonly adopted measure by municipalities, it offers limited information about the overall condition of urban forests and therefore should be used in combination with other indicators (Steenberg et al., 2013). More research is needed to investigate the projected effects on not only the quantity but the quality (health condition) of urban forests resulting from different policy interventions. Such studies should include analysis of disservices of trees (e.g., potential increase in maintenance costs and risks of damaging properties after an extreme weather event) as well as the full range of benefits (e.g., the secondary mitigating effects of trees on cooling buildings). Last but not least, though the findings contributed valuable insights to future urban forest planning in densifying areas, the policy interventions tested were mainly applicable to urban areas with predominantly low-density housing (e.g., single detached houses) and low canopy cover. Future studies should consider applying the sandbox method to existing urban areas with different forms and development patterns, in order to explore plausible policy interventions tailored to the local context. 116 Chapter 5: Synthesis and Conclusion: possible pathways toward green, compact, and climate-resilient cities This chapter synthesizes the key research findings and provides possible directions for future research, taking into account the limitations of this study. More details on limitations of the methods used are provided in each of Chapters 2-4. 5.1 Research summary and overall contribution In an era of rapid urbanization and intensifying climate change, cities need creative solutions to balance the needs of accommodating an increasing urban population, coping with intensifying climate crises, and becoming more environmentally sustainable (Grimm et al., 2008). In recent years, urban forests have been increasingly recognized and included in municipal policies because of the various climate- and livability-related benefits that they provide. These benefits help cities address climate change issues in urban areas and are crucial in enhancing urban livability (Nesbitt et al., 2017; Säumel et al., 2016). However, it is still unclear how the newly integrated urban forestry policies and actions interact with (other) climate change and urban planning policies. Evidence has shown potential conflicts among policies and policy implementation processes at the municipal level, leading to ineffective policy outcomes (Guo et al., 2019; Metro Vancouver, 2019b; Vogt et al., 2015). In the face of these challenges, it is clear that cities need cross-cutting, science-based, and locally-relevant information to understand policy interactions and make long-term viable climate action plans (Czekajlo et al., minor revisions). This dissertation attempts to advance our understanding of the interactions (alignment/synergies and discrepancies/trade-offs) between urban forestry policies and various climate change and urban planning policies in densifying cities. Using mixed methods (e.g., policy analysis, scenario planning, and geospatial analysis), the dissertation examined current policy interactions (especially conflicts and trade-offs), as 117 well as potential opportunities for cities to better sustain urban forests in spite of emerging critical climate change and population growth challenges. This dissertation comprises three independent yet connected studies, spanning a range from policies across Canada to detailed modelling in a case study neighbourhood. The first two studies (Chapter 2 and Chapter 3) focus on current municipal policies and their interactions. Chapter 2 is the first known study to date to assess the level of alignment of climate change policies and urban forestry policies in the 20 largest Canadian cities. Chapter 3 is one of the first few attempts, to our knowledge, to investigate the relationships (especially trade-offs) of policies on climate action, climate-focused urban planning, and urban forestry in densifying cities, via a case study of municipalities in Metro Vancouver, Canada. Building on the findings of these two chapters, Chapter 4 focuses on alternative urban forest futures and plausible solutions. With the use of a sandbox approach and simulated urban form and urban tree data (from 2020 to 2050), Chapter 4 explores and evaluates plausible policy interventions for cities to better align and integrate urban forests into climate action and urban planning processes. 5.2 Synthesis of key results 5.2.1 Are municipal climate change and urban forestry policies well aligned? This section focuses on the research question: To what extent are urban forests considered and integrated into climate change governance and policies, and vice versa? The analysis of climate change and urban forestry policies of the largest 20 Canadian cities revealed significant discrepancies and omissions between these two policy areas in baseline information, use of terminologies, actor/stakeholder engagement, and action priorities. This poses potential problems in policy implementation and management actions. Most cities defined their urban forests differently, highlighting locally-specific 118 understanding and needs, yet a lack of cohesion across Canadian municipalities concerning urban forest planning and management. Across most cities, both types of policies included general and locally relevant information related to the impacts of climate change. However, only three (15 %) of the cities have developed climate change and urban forestry policies that align to some extent. Gaps and inconsistencies found between and within many municipalities’ policies may present a major barrier to effective policy implementation and mutually-reinforcing management actions, potentially leading to conflicting on-the-ground practices and policy outcomes. Given the severity and frequency with which the effects of climate change are being felt in Canada, and the difficulties many cities face in achieving their climate targets, this assessment of city performance on climate change and urban forestry policies provides a wake-up call to policy-makers. It can also serve as a first step towards a roadmap of opportunities for better integration and coordination between urban forest and climate change policies. 5.2.2 How do urban forestry policies interact with climate action and urban planning policies in the policy-implementation-outcome spectrum? This section focuses on the research question: What are the potential trade-offs and synergies among policies related to climate action, climate-focused urban planning, and urban forestry? Following up on the results of the broad policy analysis, Chapter 3 takes a closer look at issues and opportunities arising in the policy-implementation-outcome spectrum. Through semi-structured interviews with experts from municipalities in the Metro Vancouver region, the study explored key trade-offs and synergies among climate, urban planning, and urban forestry policies, as well as policy implementation processes and outcomes. Despite a shared goal of building a low-carbon and resilient urban region, the study shows that such policies, though potentially complementary, when being implemented more often collide with each other. This results in declining urban 119 forests and loss of critical ecosystem services and community resilience to climate change. Significant trade-offs and synergies were identified between climate and urban planning policies and urban forestry policies, at the level of implementation and outcomes, especially with (re)developments and grey infrastructure programs which tend to overrule urban forestry policies (e.g., tree protection bylaws). More trade-offs were found than synergies. The issues (especially trade-offs) found in Metro Vancouver are consistent with those found in other cities in Canada and elsewhere (Guo et al., 2019; Jim, 2017). The study also explored areas where potential solutions lie, including enhancing political priority of urban forestry issues and providing more policy support and resources, encouraging cross-department collaborations, and increasing education and engagement opportunities for stakeholders backed by more research and data. As cities continue to grow and face increasing climate change impacts, it is urgent and crucial for these cities to proactively identify the underlying trade-offs and synergies among policies and practices, and to develop actions to address the trade-offs and enhance synergies, in order to create “win-win” solutions for lower-carbon and more resilient cities that are both compact and green. 5.2.3 What urban forestry policy interventions can cities take to better sustain their urban forests amid climate change and densification? The section addresses the research question: What plausible urban forestry policy interventions in the areas of (re)development and infrastructure can cities implement to better sustain their urban forests, despite densification and climate change? The study presents an innovative perspective on the evaluation of municipal urban forestry policy interventions. Building on the key findings on policy interactions from Chapter 3 and simulated urban form and tree data derived from the UGUD project, this study identified and assessed 6 sets of plausible urban forestry policy interventions (11 different policy interventions in total) on parks, streets, and private land, that cities can implement to better sustain their urban forests despite densification and climate change. 120 Substantial improvements in urban forest attributes and livability co-benefits were found for most of the tested policy interventions. Bold and innovative ambitious-effort interventions (e.g., creating a blue-green street network with 4 rows of street trees) lead to more substantive improvements than moderate-effort interventions. However, even applying all of the ambitious-effort interventions would not meet Vancouver’s current 30% canopy target. Not meeting this key urban forestry policy target illustrates how hard it will be to reach high canopy or green equity targets for cities. It suggests that major policy barriers or trade-offs remain with the levels of urban forestry interventions and urban density assessed in this study. The overall findings reveal several key directions and factors for municipalities to consider when planning and managing their urban forests while balancing the increasing need to densify: 1) adopting a holistic view of the urban forest system (park, street, and private trees) in policy making and implementation; 2) integrating green equity into the early stages of policy making and implementation; 3) prioritizing both mature tree protection and maintenance of newly planted trees; 4) establishing robust public engagement and stewardship mechanisms; 5) introducing stronger urban forestry policies relative to redevelopment and density policies, if a balance (synergy) among climate action, density, and urban forestry goals is to be attained. As cities continue to grow and densify, they have reached a critical point in planning their next moves to better integrate grey and green infrastructure and to meet the overall targets or levels that are needed to support green, livable, and climate-resilient cities. 5.3 Limitations and future research A key area of future research is to deepen the understanding of interactions among various interconnected policies, such as policies related to urban forestry, climate action, and land use planning, at the municipal and other levels of government. Despite some research on the interplays of climate change and related policies such as energy, transportation, built environment, and zoning (Dale et al., 2020; Spyridaki & Flamos, 2014; Viguié & Hallegatte, 2012), very little research has been done to explore the interactions between urban forestry policies and climate (and related) policies at 121 municipal and/or other levels of government. This dissertation is one of few studies trying to understand the policy interactions and their implications from the perspective of urban forestry policies and practices. However, there are several key limitations of the research work in the dissertation that could be addressed by future research. First, the dissertation focused primarily on policy interactions and implications from an urban-forestry-centred perspective. For example, the results presented in Chapter 3 were based on interviews with experts in urban forestry or allied fields, such as green infrastructure or landscape planning, without examining other fields such as private development and transportation planning that may experience different synergies and trade-offs. Additionally, the dissertation centred on municipal policies, with limited analyses and discussions of policies at other levels of government (e.g., provincial and national). In reality, urban forest planning and management are often influenced by multiple levels of government (Lawrence et al., 2013). As more cities integrate urban forests and urban forestry policies into their climate action plans, more studies are needed to examine relevant policies and their interactions at various levels of government and fields beyond urban forestry, such as infrastructure and utilities, housing and development, and climate change mitigation and adaptation. The findings of the three stages of research in this dissertation all highlighted the importance of stakeholder engagement and stewardship in urban forest planning, policy making, and implementation processes. While municipal governments usually lead the development and implementation of urban forestry policies, it is important to engage local residents in these processes to ensure that their preferences and priorities are accurately reflected in urban forestry policies and to get their support for smooth and effective policy implementation (Ordóñez, 2015; Sheppard et al., 2017). Despite an increasing number of urban forestry engagement and stewardship programs, it is evident that public participation and stewardship on urban forestry issues is still limited (Ordóñez, 2015; Ordóñez & Duinker, 2013). Due to scope limitations, this dissertation only briefly examined the roles of citizens and community groups in urban forestry policy making and implementation processes (in Chapter 2 and 3 specifically). More research 122 is needed to understand best practices to effectively engage and involve local communities with diverse social-economic backgrounds, particularly under-resourced groups, to ensure that their opinions and priorities are fully captured in urban forestry policy making and implementation processes, and their needs and preferences are considered for education, awareness building and culture shifting measures (Krajter Ostoić & Konijnendijk van den Bosch, 2015; Roman et al., 2018). Scenario planning, which originated in business management, has gained momentum in other disciplines (Barron, 2018; Hilde & Paterson, 2014). In the field of urban forestry, scenario planning has seen some adoption for long-term visioning and planning purposes, but wider application is still limited (Barron, 2018; Bolleter & Hooper, 2021; Hilde & Paterson, 2014; Langenheim et al., 2019). Trees take decades to establish and mature. In an era of rapid urbanization and climate change, it is essential for urban foresters to consider future changes and uncertainties when they make decisions about trees now. For example, arborists need to select and plant tree species now that they believe can withstand the projected climate change impacts decades later (Thompson, 2020). In this dissertation, a limited selection of possible urban forestry policy interventions and scenarios was examined (in Chapter 4). The projections of the intervention outcomes were rough estimates as they were based on a series of simplified assumptions on tree mortality rates, species and sizes, and spacings, due to the nature of scenario planning methods and scope limitations. More research using a scenario planning approach testing the effects of different designs and management decisions (e.g., planting different species or at different locations) is needed to help cities gain a broader understanding of possible pathways to create “future-proofed” urban forests (Thompson, 2020, para. 15). In addition, the evaluation of future urban forestry policy interventions was merely focused on the cumulative effects of each intervention (e.g., greening all the street segments or all the redeveloped private parcels), without examining the effect on a narrower scale, such as the site scale. As a result, site-specific factors, such as soil depth and setbacks from utilities, were omitted in the design and analyses of future 123 urban forestry policy interventions, with only general assumptions made (e.g., leaving tree spacing slightly wider than the current requirement to consider potential space competitions). Future studies should incorporate the existing and planned site-specific factors and propose feasible design and planning solutions to alleviate the tension between urban forests and density. For example, more studies could be done to provide recommendations on plausible policy interventions organized by building or population density level, land use type, or building type, coupled with site-scale three-dimensional visualizations (e.g., cross sections). These results are crucial for decision makers, practitioners, and community members to gain a comprehensive understanding of the complexities surrounding the division of public and private space and the current and future dynamics between trees and other urban infrastructure (e.g., buildings, pavement, utilities, and urban soils). Finally, this dissertation focused heavily on Canadian cities, especially within the Metro Vancouver region, which potentially restricts its ability to offer valuable and applicable references for cities beyond this locality or outside of Canada. Future research can be conducted in other cities to gain locally-specific information and patterns of outcomes. This is particularly relevant when cities are making strategic plans for climate action, future development, and urban forest management, since they are highly dependent on geographical locations and conditions, local climate and site conditions, governance structures, and projections of climate change impacts and population growth. Locally specific data are also critical for effective community engagement and stewardship on urban forest issues and management, which has proven to be increasingly important for effective holistic urban forest planning and management both by the present research and by previous studies (Carmichael & McDonough, 2019; Dwyer et al., 2003). 5.4 Final thoughts Cities are facing increasing challenges due to population growth and climate change. This dissertation aims to offer fellow researchers, policymakers, and practitioners a different perspective on the interactions among municipal policies related to urban forestry, climate action, and urban planning. In addition to recognizing the current 124 discrepancies and trade-offs among these interconnected policies, the dissertation highlights plausible opportunities for cities to resolve these trade-offs and better integrate urban forests into climate action and urban planning processes, using sandboxes and alternative future scenarios. Although the dissertation is primarily focused on Canadian cities, the outcomes can provide important and applicable references to cities in other parts of the world. According to the findings, cities need to plan strategically for emerging trends and uncertainties (chapters 3 and 4), align policies for clarity and consistency (chapters 2 and 3), systemize and coordinate policy implementation and outcomes for more effective results (all chapters) in integrating and implementing various climate change and related policies, as illustrated in the framework provided in Figure 5.1. Figure 5.1 A framework for key stages of policy making and implementation and underlying critical factors for successful policy implementation, based on research findings of this dissertation 125 The dissertation also highlights the importance of several key factors in policy making and implementation processes - strong political will and support, thorough understanding of urban forests, engaged stakeholders, adequate funding and resources, and a collaborative environment, as summarized in Figure 5.1 and expressed in more detail as recommendations for governments and communities in Figure 5.2. Specifically, the gaps and discrepancies between urban forestry and climate change policies across and within Canadian cities, as identified in Chapter 2, highlight the critical need for more robust policy support. This could mean one or more clearly defined policies, aligned to the focus of planning and management of urban forest resources at the municipal level. Additionally, the findings emphasize the importance of greater collaboration within the municipal government and with external stakeholders, which requires a collaborative environment enabled by effective communication and engagement plans. The synergies and trade-offs in the policy-implementation-outcome spectrum in Chapter 3 underscore the urgency of aligning and coordinating municipal policies and implementation for the most desirable outcomes. To be able to do it, cities need to adopt a holistic view of the urban forest system and gain a thorough understanding of their urban forests through research and field experiments. This is particularly crucial in enhancing the political priority of urban forestry, which helps solicit adequate funding and resources and foster more meaningful collaboration for urban forestry work. Lastly, Chapter 4 demonstrated the importance of long-term strategic planning processes and proper compliance and monitoring mechanisms when developing and implementing policies, particularly in an era of rapid changes and uncertainties. 126 Figure 5.2 Recommendations for effective urban forest policy making and implementation based on research findings from this dissertation. The author hopes that the findings of this dissertation can provide cities (especially in areas undergoing densification) with useful policy directions, quantified examples and inspiring ideas for a greener, more resilient, and livable future. 127 Bibliography Akbari, H., Pomerantz, M., & Taha, H. (2001). Cool surfaces and shade trees to reduce energy use and improve air quality in urban areas. Solar Energy, 70(3), 295–310. https://doi.org/10.1016/S0038-092X(00)00089-X Bai, X., Dawson, R. J., Ürge-Vorsatz, D., Delgado, G. C., Barau, A. S., Dhakal, S., Dodman, D., Leonardsen, L., Masson-Delmotte, V., Riberts, D. C., & Schultz, S. (2018). Six research priorities for cities and climate change. Nature, 555, 23–25. https://doi.org/10.1038/d41586-018-02409-z Baines, O., Wilkes, P., & Disney, M. (2020). Quantifying urban forest structure with open-access remote sensing data sets. Urban Forestry & Urban Greening, 50, 126653. https://doi.org/10.1016/j.ufug.2020.126653 Baró, F., Chaparro, L., Langemeyer, J., Nowak, D. J., & Terradas, J. (2017). Chapter 1. Contribution of Ecosystem Services to Air Quality and Climate Change Mitigation Policies: The Case of Urban Forests in Barcelona, Spain. In J. Blum (Ed.), Urban Forests: Ecosystem Services and Management (1st Edition, pp. 21–54). Apple Academic Press. https://doi.org/10.1201/9781315366081-10 Barr, J., & Cohen, J. P. (2014). The floor area ratio gradient: New York City, 1890–2009. Regional Science and Urban Economics, 48, 110–119. https://doi.org/10.1016/j.regsciurbeco.2014.03.004 Barron, S. (2018). Future Suburban Forests in a Changing Climate: An approach for integrated planning and design in compact communities. 128 Bauer, A., & Steurer, R. (2014). Multi-level governance of climate change adaptation through regional partnerships in Canada and England. Geoforum, 51, 121–129. https://doi.org/10.1016/j.geoforum.2013.10.006 Baynham, M., & Stevens, M. (2014). Are we planning effectively for climate change? An evaluation of official community plans in British Columbia. Journal of Environmental Planning and Management, 57(4), 557–587. https://doi.org/10.1080/09640568.2012.756805 BC Assessment. (2019). BC Assessment—Independent, uniform and efficient property assessment [Data set]. https://www.bcassessment.ca/ Bolleter, J., & Hooper, P. (2021). The importance of place-based narrative in suburban forest planning. Journal of Urban Design, 26(2), 209–234. https://doi.org/10.1080/13574809.2020.1851594 Boulton, C., Dedekorkut-Howes, A., & Byrne, J. (2018). Factors shaping urban greenspace provision: A systematic review of the literature. Landscape and Urban Planning, 178, 82–101. https://doi.org/10.1016/j.landurbplan.2018.05.029 Brack, C. L. (2002). Pollution mitigation and carbon sequestration by an urban forest. Environmental Pollution, 116, S195–S200. https://doi.org/10.1016/S0269-7491(01)00251-2 Brandt, L., Derby Lewis, A., Fahey, R., Scott, L., Darling, L., & Swanston, C. (2016). A framework for adapting urban forests to climate change. Environmental Science & Policy, 66, 393–402. https://doi.org/10.1016/j.envsci.2016.06.005 129 Bratman, G. N., Daily, G. C., Levy, B. J., & Gross, J. J. (2015). The benefits of nature experience: Improved affect and cognition. Landscape and Urban Planning, 138, 41–50. https://doi.org/10.1016/j.landurbplan.2015.02.005 Braun, V., & Clarke, V. (2006). Using thematic analysis in psychology. Qualitative Research in Psychology, 3(2), 77–101. https://doi.org/10.1191/1478088706qp063oa British Columbia Coroners Service. (2022). A Review of Heat-Related Deaths in B.C. in Summer 2021 (p. 53). https://www2.gov.bc.ca/assets/gov/birth-adoption-death-marriage-and-divorce/deaths/coroners-service/death-review-panel/extreme_heat_death_review_panel_report.pdf Brittlebank, W., & Clos, J. (2014). Compact cities to address climate change. In Climate Action. http://www.climateaction.org/climate-leader-papers/compact_cities_to_address_climate_change Brown, M. A., Southworth, F., & Sarzynski, A. (2008). Shrinking the Carbon Footprint of Metropolitan America (pp. 1–16). papers2://publication/uuid/AE6A50EA-CD42-47A3-BF29-BD6566EB78B8 Brownstone, D., & Golob, T. F. (2009). The impact of residential density on vehicle usage and energy consumption. Journal of Urban Economics, 65(1), 91–98. https://doi.org/10.1016/j.jue.2008.09.002 Brunner, J., & Cozens, P. (2013). ‘Where Have All the Trees Gone?’ Urban Consolidation and the Demise of Urban Vegetation: A Case Study from Western Australia. Planning Practice and Research, 28(2), 231–255. https://doi.org/10.1080/02697459.2012.733525 130 Bulkeley, H. (2010). Cities and the Governing of Climate Change. Annual Review of Environment and Resources, 35(1), 229–253. https://doi.org/10.1146/annurev-environ-072809-101747 Burch, S. (2010). In pursuit of resilient, low carbon communities: An examination of barriers to action in three Canadian cities. Energy Policy, 38(12), 7575–7585. https://doi.org/10.1016/j.enpol.2009.06.070 Burgess, R. (2002). The Compact City Debate: A Global Perspective. In R. Burgess & M. Jenks (Eds.), Compact Cities: Sustainable Urban Forms for Developing Countries (1st ed., pp. 9–24). Routledge. https://doi.org/10.4324/9780203478622-6 Burton, E. (2000). The Compact City: Just or Just Compact? A Preliminary Analysis. Urban Studies, 37(11), 1969–2006. https://doi.org/10.1080/00420980050162184 Bush, E., & Lemmen, D. S. (2019). Canada’s changing climate report. (p. 444) [Government report]. Government of Canada. http://publications.gc.ca/collections/collection_2019/eccc/En4-368-2019-eng.pdf Carmichael, C. E., & McDonough, M. H. (2019). Community Stories: Explaining Resistance to Street Tree-Planting Programs in Detroit, Michigan, USA. Society & Natural Resources, 32(5), 588–605. https://doi.org/10.1080/08941920.2018.1550229 Chen, Y., Day, S. D., Wick, A. F., & McGuire, K. J. (2014). Influence of urban land development and subsequent soil rehabilitation on soil aggregates, carbon, and hydraulic conductivity. Science of The Total Environment, 494–495, 329–336. https://doi.org/10.1016/j.scitotenv.2014.06.099 131 Cheng, Z., Nitoslawski, S., Konijnendijk van den Bosch, C., Sheppard, S., Nesbitt, L., & Girling, C. (2021). Alignment of municipal climate change and urban forestry policies: A Canadian perspective. Environmental Science & Policy, 122, 14–24. https://doi.org/10.1016/j.envsci.2021.04.005 Chi, D., Aerts, R., Van Nieuwenhuyse, A., Bauwelinck, M., Demoury, C., Plusquin, M., Nawrot, T. S., Casas, L., & Somers, B. (2022). Residential Exposure to Urban Trees and Medication Sales for Mood Disorders and Cardiovascular Disease in Brussels, Belgium: An Ecological Study. Environmental Health Perspectives, 130(5), 057003. https://doi.org/10.1289/EHP9924 Church, S. P. (2018). From street trees to natural areas: Retrofitting cities for human connectedness to nature. Journal of Environmental Planning and Management, 61(5–6), 878–903. https://doi.org/10.1080/09640568.2018.1428182 City of Coquitlam. (n.d.). Frontage Works Program. Retrieved May 23, 2022, from https://www.coquitlam.ca/362/Frontage-Works-Program City of Surrey. (n.d.). Development Cost Charges. Retrieved May 26, 2022, from https://www.surrey.ca/renovating-building-development/engineering-infrastructure/development-cost-charges City of Surrey. (2021, February 3). Tree Sale Program | City of Surrey. https://www.surrey.ca/renovating-building-development/trees-yard-garden/tree-sale-program City of Vancouver. (n.d.-a). Development Cost Levies. Retrieved May 26, 2022, from https://vancouver.ca/home-property-development/development-cost-levies.aspx 132 City of Vancouver. (2018). Engineering Design Manual (p. 348). City of Vancouver. https://bids.vancouver.ca/bidopp/RFA/Documents/PS20181461-CityofVancouver-EngineeringDesignManualFirstEdition2018.PDF City of Vancouver. (2019). LiDAR 2013 [Data set]. City of Vancouver Open Data Portal. https://opendata.vancouver.ca/explore/dataset/lidar-2013/ City of Vancouver. (2022a). Bulletin: Sustainable Large Developments. City of Vancouver. https://bylaws.vancouver.ca/bulletin/bulletin-sustainable-large-developments.pdf City of Vancouver. (2022b). Memorandom: City of Vancouver 2021 Census Population and Dwelling Counts and Metro Vancouver Growth Projection Update (p. 8) [Memorandum]. City of Vancouver. https://vancouver.ca/files/cov/2022-02-28-2021-census-population-dwelling-counts-and-metro-van-growth.pdf City of Vancouver. (2022c). The Vancouver Plan 2050. City of Vancouver. https://vancouverplan.ca/wp-content/uploads/Vancouver-Plan-2022-09-23-1.pdf City of Vancouver. (2022d). PROTECTION OF TREES BY-LAW NO. 9958. City of Vancouver. https://bylaws.vancouver.ca/9958c.PDF City of Vancouver, C. of. (n.d.-b). Blue green systems. Retrieved January 16, 2023, from https://vancouver.ca/home-property-development/blue-green-systems.aspx City of Vancouver & Vancouver Board of Parks and Recreation. (2018). Urban Forest Strategy: 2018 Update. In City of Vancouver and Vancouver Board of Parks and Recreation (pp. 60–60). https://vancouver.ca/files/cov/urban-forest-strategy.pdf Clark, C., Ordóñez, C., & Livesley, S. J. (2020). Private tree removal, public loss: Valuing and enforcing existing tree protection mechanisms is the key to retaining 133 urban trees on private land. Landscape and Urban Planning, 203, 103899. https://doi.org/10.1016/j.landurbplan.2020.103899 Climate Action Tracker. (2022, December 20). Canada. Climate Action Tracker. https://climateactiontracker.org/countries/canada/ Collaborative for Advanced Landscape Planning (CALP). (n.d.). Cool ’Hood Champs. Collaborative for Advanced Landscape Planning (CALP). Retrieved January 19, 2023, from https://calp.forestry.ubc.ca/cool-hood-champs/ Conway, T. M. (2016). Tending their urban forest: Residents’ motivations for tree planting and removal. Urban Forestry & Urban Greening, 17, 23–32. https://doi.org/10.1016/j.ufug.2016.03.008 Conway, T. M., & Urbani, L. (2007). Variations in municipal urban forestry policies: A case study of Toronto, Canada. Urban Forestry & Urban Greening, 6(3), 181–192. https://doi.org/10.1016/j.ufug.2007.07.003 Croeser, T., Ordóñez, C., Threlfall, C., Kendal, D., van der Ree, R., Callow, D., & Livesley, S. J. (2020). Patterns of tree removal and canopy change on public and private land in the City of Melbourne. Sustainable Cities and Society, 56, 102096. https://doi.org/10.1016/j.scs.2020.102096 Czekajlo, A., Cheng, Z., Barron, S., Girling, C., & Nesbitt, L. (2022). Trees and densification: Modelling four urban forest scenarios for 2050 [Minor revision]. Arboriculture & Urban Forestry. Dale, A., Robinson, J., King, L., Burch, S., Newell, R., Shaw, A., & Jost, F. (2020). Meeting the climate change challenge: Local government climate action in British 134 Columbia, Canada. Climate Policy, 20(7), 866–880. https://doi.org/10.1080/14693062.2019.1651244 Davies, H. J., Doick, K. J., Hudson, M. D., & Schreckenberg, K. (2017). Challenges for tree officers to enhance the provision of regulating ecosystem services from urban forests. Environmental Research, 156, 97–107. https://doi.org/10.1016/j.envres.2017.03.020 Davies, Z. G., Edmondson, J. L., Heinemeyer, A., Leake, J. R., & Gaston, K. J. (2011). Mapping an urban ecosystem service: Quantifying above-ground carbon storage at a city-wide scale. Journal of Applied Ecology, 48(5), 1125–1134. https://doi.org/10.1111/j.1365-2664.2011.02021.x de Vries, S., van Dillen, S. M. E., Groenewegen, P. P., & Spreeuwenberg, P. (2013). Streetscape greenery and health: Stress, social cohesion and physical activity as mediators. Social Science & Medicine, 94, 26–33. https://doi.org/10.1016/j.socscimed.2013.06.030 Diamond Head Consulting Ltd. (2017). Urban Forest Climate Adaptation Framework for Metro Vancouver Tree Species Selection, Planting and Management (pp. 115–115). http://www.metrovancouver.org/services/regional-planning/PlanningPublications/UrbanForestClimateAdaptationFrameworkTreeSpeciesSelection.pdf Doick, K. J. (2022). Climate change and urban forests: Can urban forests help cities adapt to climate change? Frest Resesarch, The Government of the United Kingdom. https://cdn.forestresearch.gov.uk/2022/04/21_0024_Leaflet-CC-factsheet-Urban-forests_wip06_Acc.pdf 135 Doll, S., & Duinker, P. N. (2020). Characterization and Justification of Trees on an Inner-City Golf Course in Halifax, Canada: An Investigation into the Ecological Integrity of Institutional Greenspace. Forests, 11(1), Article 1. https://doi.org/10.3390/f11010096 Dowell, K. (2017). ASSESSING ADOPTER EXPERIENCE AND TREE HEALTH FOR LOCAL ENHANCEMENT AND APPRECIATION OF FOREST (LEAF)’S ADOPT-A- STREET-TREE PROGRAM IN THE CITY OF TORONTO [University of Toronto]. https://tspace.library.utoronto.ca/bitstream/1807/81307/1/FOR3008H%20-%20Capstone%20Report.pdf Duinker, P. N., Ordóñez, C., Steenberg, J. W. N., Miller, K. H., Toni, S. A., & Nitoslawski, S. A. (2015). Trees in Canadian Cities: Indispensable Life Form for Urban Sustainability. Sustainability, 7(6), Article 6. https://doi.org/10.3390/su7067379 Dwyer, J., Nowak, D., & Noble, M. (2003). Sustaining Urban Forests. Arboriculture & Urban Forestry, 29(1), 49–55. https://doi.org/10.48044/jauf.2003.007 ElementsLab. (n.d.). Urban Greening vs. Urban Densification. Retrieved December 16, 2022, from https://elementslab.ca/urban-greening-vs-urban-densification/ Endreny, T. A. (2018). Strategically growing the urban forest will improve our world. Nature Communications, 9(1), 1160–1160. https://doi.org/10.1038/s41467-018-03622-0 136 Erickson, D. L. (2006a). Chapter 1 Connected Open Space: The Metropolitan Scale. In MetroGreen: Connecting Open Space in North American Cities (1st ed., pp. 1–3). Island Press. Erickson, D. L. (2006b). MetroGreen: Connecting open space in North American cities (p. 352). Island Press. Erickson, P., & Tempest, K. (2015). Keeping cities green: Avoiding carbon lock-in due to urban devel (Working Paper No. 2015–11; p. 30). Stockholm Environmental Institute. https://mediamanager.sei.org/documents/Publications/Climate/SEI-WP-2015-10-C40-Cities-carbon-lock-in.pdf Escobedo, F. J., Giannico, V., Jim, C. Y., Sanesi, G., & Lafortezza, R. (2019). Urban forests, ecosystem services, green infrastructure and nature-based solutions: Nexus or evolving metaphors? Urban Forestry & Urban Greening, 37, 3–12. https://doi.org/10.1016/j.ufug.2018.02.011 Escobedo, F. J., Kroeger, T., & Wagner, J. E. (2011). Urban forests and pollution mitigation: Analyzing ecosystem services and disservices. Environmental Pollution, 159(8), 2078–2087. https://doi.org/10.1016/j.envpol.2011.01.010 Escobedo, F. J., Varela, S., Zhao, M., Wagner, J. E., & Zipperer, W. (2010). Analyzing the efficacy of subtropical urban forests in offsetting carbon emissions from cities. Environmental Science & Policy, 13(5), 362–372. https://doi.org/10.1016/j.envsci.2010.03.009 Ferrer, A. L. C., Thomé, A. M. T., & Scavarda, A. J. (2018). Sustainable urban infrastructure: A review. Resources, Conservation and Recycling, 128, 360–372. https://doi.org/10.1016/j.resconrec.2016.07.017 137 Ferrini, F., Konijnendijk, C. C., & Fini, A. (Eds.). (2017). Routledge Handbook of Urban Forestry (1st Edition, p. 524). Routledge. https://www.routledge.com/Routledge-Handbook-of-Urban-Forestry-1st-Edition/Ferrini-Konijnendijk-van-den-Bosch-Fini/p/book/9781138647282 Food and Agriculture Organization of the United Nations. (2018). Forests and sustainable cities: Inspiring stories from the world (pp. 92–92). http://www.fao.org/3/I8838EN/i8838en.pdf Foran, C. M., Baker, K. M., Narcisi, M. J., & Linkov, I. (2015). Susceptibility assessment of urban tree species in Cambridge, MA, from future climatic extremes. Environment Systems and Decisions, 35(3), 389–400. https://doi.org/10.1007/s10669-015-9563-4 Galvin, M. F., Grove, M. j., & O’Neil-Dunne, J. (2006). A report on Baltimore City’s present and potential urban tree canopy (p. 17). Maryland Forest Services. https://www.fs.usda.gov/nrs/utc/reports/2006_UTC_Report_Baltimore.pdf Garrison, J. D. (2019). Seeing the park for the trees: New York’s “Million Trees” campaign vs. The deep roots of environmental inequality. Environment and Planning B: Urban Analytics and City Science, 46(5), 914–930. https://doi.org/10.1177/2399808317737071 Gibbons, K. H., & Ryan, C. M. (2015). Characterizing comprehensiveness of urban forest management plans in Washington State. Urban Forestry & Urban Greening, 14(3), 615–624. https://doi.org/10.1016/j.ufug.2015.06.003 Government of Canada. (2016). Pan-Canadian Framework on Clean Growth and Climate Change: Canada’s plan to address climate change and grow the 138 economy (Government Report No. En4-294/2016E-PDF; p. 78). Environment and Climate Change Canada. http://publications.gc.ca/pub?id=9.828774&sl=0 Grimm, N. B., Faeth, S. H., Golubiewski, N. E., Redman, C. L., Wu, J., Bai, X., & Briggs, J. M. (2008). Global Change and the Ecology of Cities. Science, 319(5864), 756–760. https://doi.org/10.1126/science.1150195 Guo, T., Morgenroth, J., Conway, T., & Xu, C. (2019). City-wide canopy cover decline due to residential property redevelopment in Christchurch, New Zealand. Science of The Total Environment, 681, 202–210. https://doi.org/10.1016/j.scitotenv.2019.05.122 Guyadeen, D., Thistlethwaite, J., & Henstra, D. (2019). Evaluating the quality of municipal climate change plans in Canada. Climatic Change, 152(1), 121–143. https://doi.org/10.1007/s10584-018-2312-1 Haaland, C., & Konijnendijk van den Bosch, C. (2015). Challenges and strategies for urban green-space planning in cities undergoing densification: A review. Urban Forestry & Urban Greening, 14(4), 760–771. https://doi.org/10.1016/J.UFUG.2015.07.009 Hajat, S., & Kosatky, T. (2010). Heat-related mortality: A review and exploration of heterogeneity. Journal of Epidemiology and Community Health, 64(9), 753–760. https://doi.org/10.1136/jech.2009.087999 Hamin, E. M., & Gurran, N. (2009). Urban form and climate change: Balancing adaptation and mitigation in the U.S. and Australia. Habitat International, 33(3), 238–245. https://doi.org/10.1016/j.habitatint.2008.10.005 139 Hartig, T., Evans, G. W., Jamner, L. D., Davis, D. S., & Gärling, T. (2003). Tracking restoration in natural and urban field settings. Journal of Environmental Psychology, 23(2), 109–123. https://doi.org/10.1016/S0272-4944(02)00109-3 Herbert, Y., Dale, A., & Stashok, C. (2022). Canadian cities: Climate change action and plans. Buildings and Cities, 3(1), Article 1. https://doi.org/10.5334/bc.251 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), 167–200. Hilde, T., & Paterson, R. (2014). Integrating ecosystem services analysis into scenario planning practice: Accounting for street tree benefits with i-Tree valuation in Central Texas. Journal of Environmental Management, 146, 524–534. https://doi.org/10.1016/j.jenvman.2014.05.039 Hobbie, S. E., & Grimm, N. B. (2020). Nature-based approaches to managing climate change impacts in cities. Philosophical Transactions of the Royal Society B: Biological Sciences, 375(1794), 20190124. https://doi.org/10.1098/rstb.2019.0124 Human Rights Watch. (2021, October 5). Canada: Disastrous Impact of Extreme Heat. https://www.hrw.org/news/2021/10/05/canada-disastrous-impact-extreme-heat Janowiak, M. K., Brandt, L. A., Wolf, K. K., Brady, M., Darling, L., Derby Lewis, A., Fahey, R. T., Giesting, K., Hall, E., Henry, M., Hughes, M., Miesbauer, J. W., Marcinkowski, K., Ontl, T., Rutledge, A., Scott, L., & Swanston, C. W. (2021). Climate adaptation actions for urban forests and human health (Gen. Tech. Rep. 140 NRS-203; p. 115). U.S. Department of Agriculture, Forest Service, Northern Research Station. https://doi.org/10.2737/NRS-GTR-203 Jenkins, K., Hall, J., Glenis, V., Kilsby, C., McCarthy, M., Goodess, C., Smith, D., Malleson, N., & Birkin, M. (2014). Probabilistic spatial risk assessment of heat impacts and adaptations for London. Climatic Change, 124(1–2), 105–117. https://doi.org/10.1007/s10584-014-1105-4 Jim, C. Y. (2005). Monitoring the performance and decline of heritage trees in urban Hong Kong. Journal of Environmental Management, 74(2), 161–172. https://doi.org/10.1016/J.JENVMAN.2004.08.014 Jim, C. Y. (2017). Constraints to Urban Trees and Their Remedies in the Built Environment. In F. Ferrini, C. C. Konijnendijk, & A. Fini (Eds.), Routledge Handbook of Urban Forestry (1st ed., pp. 273–290). Routledge. Jim, C. Y., Konijnendijk van den Bosch, C., & Chen, W. Y. (2018). Acute Challenges and Solutions for Urban Forestry in Compact and Densifying Cities. Journal of Urban Planning and Development, 144(3), 04018025. https://doi.org/10.1061/(ASCE)UP.1943-5444.0000466 Kaźmierczak, A. (2013). The contribution of local parks to neighbourhood social ties. Landscape and Urban Planning, 109(1), 31–44. https://doi.org/10.1016/j.landurbplan.2012.05.007 Koeser, A., Hauer, R., Norris, K., & Krouse, R. (2013). Factors influencing long-term street tree survival in Milwaukee, WI, USA. Urban Forestry & Urban Greening, 12(4), 562–568. https://doi.org/10.1016/j.ufug.2013.05.006 141 Krajter Ostoić, S., & Konijnendijk van den Bosch, C. C. (2015). Exploring global scientific discourses on urban forestry. Urban Forestry & Urban Greening, 14(1), 129–138. https://doi.org/10.1016/j.ufug.2015.01.001 Kuehler, E., Hathaway, J., & Tirpak, A. (2017). Quantifying the benefits of urban forest systems as a component of the green infrastructure stormwater treatment network. Ecohydrology, 10(3), e1813. https://doi.org/10.1002/eco.1813 Kuo, F. E. (2003). The role of arboriculture in a healthy social ecology. Journal of Arboriculture, 29(3), 148–155. Langenheim, N., White, M., Tapper, N., Livesley, S. J., & Ramirez-Lovering, D. (2019). Right tree, right place, right time: A visual-functional design approach to select and place trees for optimal shade benefit to commuting pedestrians. Sustainable Cities and Society, 52, 101816–101816. https://doi.org/10.1016/J.SCS.2019.101816 Lantz, N., Grenier, M., & Wang, J. (2021). Urban greenness, 2001, 2011 and 2019 (No. 16-002–X; p. 9). Statistics Canada. https://www150.statcan.gc.ca/n1/pub/16-002-x/2021001/article/00002-eng.htm Larsen, S. V., Kørnøv, L., & Wejs, A. (2012a). Mind the gap in SEA: An institutional perspective on why assessment of synergies amongst climate change mitigation, adaptation and other policy areas are missing. Environmental Impact Assessment Review, 33(1), 32–40. https://doi.org/10.1016/j.eiar.2011.09.003 Larsen, S. V., Kørnøv, L., & Wejs, A. (2012b). Mind the gap in SEA: An institutional perspective on why assessment of synergies amongst climate change mitigation, 142 adaptation and other policy areas are missing. Environmental Impact Assessment Review, 33(1), 32–40. https://doi.org/10.1016/j.eiar.2011.09.003 Lawrence, A., De Vreese, R., Johnston, M., Konijnendijk van den Bosch, C. C., & Sanesi, G. (2013). Urban forest governance: Towards a framework for comparing approaches. Urban Forestry & Urban Greening, 12(4), 464–473. https://doi.org/10.1016/j.ufug.2013.05.002 Lee, C., Ory, M. G., Yoon, J., & Forjuoh, S. N. (2013). Neighborhood Walking Among Overweight and Obese Adults: Age Variations in Barriers and Motivators. Journal of Community Health, 38(1), 12–22. https://doi.org/10.1007/s10900-012-9592-6 Lee, Y. Y., Din, M. F. M., Ponraj, M., Noor, Z. Z., Iwao, K., & Chelliapan, S. (2017). Overview of Urban Heat Island (uhi) Phenomenon Towards Human Thermal Comfort. Environmental Engineering and Management Journal, 16(9), 2097–2111. Lexico.com. (n.d.-a). Definition of Synergy. In Lexico Dictionaries. Oxford University Press. Retrieved May 23, 2022, from https://www.lexico.com/definition/synergy Lexico.com. (n.d.-b). Definition of Trade-off. In Lexico Dictionaries. Oxford University Press. Retrieved May 23, 2022, from https://www.lexico.com/definition/trade-off Liu, C., & Li, X. (2012). Carbon storage and sequestration by urban forests in Shenyang, China. Urban Forestry & Urban Greening, 11(2), 121–128. https://doi.org/10.1016/j.ufug.2011.03.002 Livesley, S. J., McPherson, E. G., & Calfapietra, C. (2016). The Urban Forest and Ecosystem Services: Impacts on Urban Water, Heat, and Pollution Cycles at the 143 Tree, Street, and City Scale. Journal of Environmental Quality, 45(1), 119–124. https://doi.org/10.2134/jeq2015.11.0567 Local Enhancement & Appreciation of Forests (LEAF). (n.d.). Local Enhancement & Appreciation of Forests. In Local Enhancement & Appreciation of Forests. https://www.yourleaf.org/ Local Enhancement & Appreciation of Forests (LEAF). (2022). Homeowners. Local Enhancement & Appreciation of Forests (LEAF). https://www.yourleaf.org/homeowners Lu, Y., McCarty, J., Sezto, J., Cheng, Z., Martino, N., Girling, C., Rysanek, A., Barron, S., & Matasci, G. (2022). Modeling the Shading Effect of Vancouver’s Urban Tree Canopy in Relation to Neighborhood Variations. Arboriculture & Urban Forestry, 48(2). https://doi.org/10.48044/jauf.2022.008 Lu, Y., Scott, A., Kim, J., Curi, C. B., McCarty, J., Pardy, A., Rysanek, A., Girling, C., & Kellett, R. (2021). Integration of an energy-economy model with an urban energy model. Buildings and Cities, 2(1), Article 1. https://doi.org/10.5334/bc.71 Martin, J. (2017, July 17). Trees and sidewalks: A strategic approach to conflicts. Deeproot. https://www.deeproot.com/blog/blog-entries/trees-and-sidewalks-a-strategic-approach-to-conflicts/ May, P. B., Livesley, S. J., & Shears, I. (2013). Managing and Monitoring Tree Health and Soil Water Status During Extreme Drought in Melbourne, Victoria. Arboriculture & Urban Forestry, 39(3), 136–145. 144 McPherson, E. G., Kendall, A., & Albers, S. (2015). Million Trees Los Angeles: Carbon Dioxide Sink or Source? Proceedings of the Urban Trees Research Conference" Trees, People and the Built Environment II.", 7–19. McPherson, E. G., Nowak, D., Heisler, G., Grimmond, S., Souch, C., Grant, R., & Rowntree, R. (1997). Quantifying urban forest structure, function, and value: The Chicago Urban Forest Climate Project. Urban Ecosystems, 1(1), 49–61. https://doi.org/10.1023/A:1014350822458 McPherson, E. G., Simpson, J. R., Xiao, Q., & Wu, C. (2011). Million trees Los Angeles canopy cover and benefit assessment. Landscape and Urban Planning, 99(1), 40–50. https://doi.org/10.1016/j.landurbplan.2010.08.011 Metro Vancouver. (n.d.). Connecting the Dots: Regional Green Infrastructure Network Resource Guide (p. 48). Retrieved January 20, 2021, from http://www.metrovancouver.org/services/regional-planning/PlanningPublications/ConnectintheDots.pdf Metro Vancouver. (2019a). Climate 2050 Strategic Framework. http://www.metrovancouver.org/services/air-quality/AirQualityPublications/AQ_C2050-StrategicFramework.pdf Metro Vancouver. (2019b). Regional Tree Canopy Cover and Impervious Surfaces: Analysis of Tree Canopy Cover and Impervious Surfaces in Metro Vancouver (p. 44). http://www.metrovancouver.org/services/regional-planning/PlanningPublications/EcologicalHealth-TreeCanopyCoverImperviousSurfaces.pdf 145 Metro Vancouver. (2021). Metro 2050 Regional Growth Strategy (Draft) (p. 116). http://www.metrovancouver.org/services/regional-planning/PlanningPublications/DraftMetro2050.pdf Metro Vancouver Regional District. (n.d.). Urban Tree List for Metro Vancouver in a Changing Climate. Metro Vancouver. Retrieved January 12, 2021, from http://www.metrovancouver.org/services/regional-planning/PlanningPublications/UFA_UrbanTreesList.pdf Metro Vancouver Regional District. (2020). 2016 Generalized Land Use Classification [Data set]. Open Data Catalogue. http://www.metrovancouver.org/data/Pages/default.aspx Metro Vancouver Regional District. (2022). Metro 2050 Regional Growth Strategy (p. 123). Metro Vancouver Regional District. http://www.metrovancouver.org/services/regional-planning/PlanningPublications/Metro2050.pdf Metro Vancouver Regional Parks Service. (2018). Regional Parks Land Acquisition 2050 (p. 40). Metro Vancouver. http://www.metrovancouver.org/services/parks/ParksPublications/RegionalParksLandAcquisition2050.pdf Mi, Z., Guan, D., Liu, Z., Liu, J., Viguié, V., Fromer, N., & Wang, Y. (2019). Cities: The core of climate change mitigation. Journal of Cleaner Production, 207, 582–589. https://doi.org/10.1016/j.jclepro.2018.10.034 MillionTrees NYC. (2015). MillionTrees NYC - About MillionTrees NYC. https://www.milliontreesnyc.org/html/about/about.shtml 146 Millward, A. A., & Sabir, S. (2011). Benefits of a forested urban park: What is the value of Allan Gardens to the city of Toronto, Canada? Landscape and Urban Planning, 100(3), 177–188. https://doi.org/10.1016/j.landurbplan.2010.11.013 Mullaney, J., Lucke, T., & Trueman, S. J. (2015). A review of benefits and challenges in growing street trees in paved urban environments. Landscape and Urban Planning, 134, 157–166. https://doi.org/10.1016/j.landurbplan.2014.10.013 Nesbitt, L., Hotte, N., Barron, S., Cowan, J., & Sheppard, S. R. J. (2017). The social and economic value of cultural ecosystem services provided by urban forests in North America: A review and suggestions for future research. Urban Forestry & Urban Greening, 25, 103–111. https://doi.org/10.1016/J.UFUG.2017.05.005 Nesbitt, L., Meitner, M. J., Girling, C., Sheppard, S. R. J., & Lu, Y. (2019). Who has access to urban vegetation? A spatial analysis of distributional green equity in 10 US cities. Landscape and Urban Planning, 181, 51–79. https://doi.org/10.1016/j.landurbplan.2018.08.007 Newell, R., Dale, A., & Roseland, M. (2018). Climate Action Co-benefits and Integrated Community Planning: Uncovering the Synergies and Trade-Offs. The International Journal of Climate Change: Impacts and Responses, 10(4), 1–23. https://doi.org/10.18848/1835-7156/CGP/v10i04/1-23. Nitoslawski, S. A., Galle, N. J., Van Den Bosch, C. K., & Steenberg, J. W. N. (2019). Smarter ecosystems for smarter cities? A review of trends, technologies, and turning points for smart urban forestry. Sustainable Cities and Society, 51, 101770. https://doi.org/10.1016/j.scs.2019.101770 147 Nowak, D. J., & Crane, D. E. (2002). Carbon storage and sequestration by urban trees in the USA. Environmental Pollution, 116(3), 381–389. https://doi.org/10.1016/S0269-7491(01)00214-7 Nowak, D. J., & Greenfield, E. J. (2012). Tree and impervious cover change in U.S. cities. Urban Forestry & Urban Greening, 11(1), 21–30. https://doi.org/10.1016/j.ufug.2011.11.005 Nowak, D. J., & Greenfield, E. J. (2018). Declining urban and community tree cover in the United States. Urban Forestry & Urban Greening, 32, 32–55. https://doi.org/10.1016/J.UFUG.2018.03.006 Nowak, D. J., & Greenfield, E. J. (2020). The increase of impervious cover and decrease of tree cover within urban areas globally (2012–2017). Urban Forestry & Urban Greening, 49, 126638. https://doi.org/10.1016/j.ufug.2020.126638 Nowak, D. J., Hirabayashi, S., Doyle, M., McGovern, M., & Pasher, J. (2018). Air pollution removal by urban forests in Canada and its effect on air quality and human health. Urban Forestry & Urban Greening, 29, 40–48. https://doi.org/10.1016/j.ufug.2017.10.019 Nowak, D. J., Hoehn, R. E., Bodine, A. R., Greenfield, E. J., & O’Neil-Dunne, J. (2016). Urban forest structure, ecosystem services and change in Syracuse, NY. Urban Ecosystems, 19(4), 1455–1477. https://doi.org/10.1007/s11252-013-0326-z Nowak, D. J., Mcbride, J., & Beatty, R. (1990). Newly planted street tree growth and mortality. Journal of Arboriculture, 16(5), 124–129. OECD. (2012). Compact City Policies (p. 287). OECD Publishing. https://doi.org/10.1787/9789264167865-en 148 Ordóñez, C. (2015). Adopting public values and climate change adaptation strategies in urban forest management: A review and analysis of the relevant literature. Journal of Environmental Management, 164, 215–221. https://doi.org/10.1016/j.jenvman.2015.09.004 Ordóñez, C., & Duinker, P. (2015). Climate change vulnerability assessment of the urban forest in three Canadian cities. Climatic Change, 131(4), 531–543. https://doi.org/10.1007/s10584-015-1394-2 Ordóñez, C., & Duinker, P. N. (2013). An analysis of urban forest management plans in Canada: Implications for urban forest management. Landscape and Urban Planning, 116, 36–47. https://doi.org/10.1016/j.landurbplan.2013.04.007 Ordóñez, C., & Duinker, P. N. (2014). Assessing the vulnerability of urban forests to climate change. Environmental Reviews, 22(3), 311–321. https://doi.org/10.1139/er-2013-0078 Ordóñez, C., Threlfall, C. G., Kendal, D., Hochuli, D. F., Davern, M., Fuller, R. A., van der Ree, R., & Livesley, S. J. (2019). Urban forest governance and decision-making: A systematic review and synthesis of the perspectives of municipal managers. Landscape and Urban Planning, 189, 166–180. https://doi.org/10.1016/j.landurbplan.2019.04.020 Ordóñez, C., Threlfall, C. G., Livesley, S. J., Kendal, D., Fuller, R. A., Davern, M., van der Ree, R., & Hochuli, D. F. (2020). Decision-making of municipal urban forest managers through the lens of governance. Environmental Science & Policy, 104, 136–147. https://doi.org/10.1016/j.envsci.2019.11.008 149 Ordóñez-Barona, C., Bush, J., Hurley, J., Amati, M., Juhola, S., Frank, S., Ritchie, M., Clark, C., English, A., Hertzog, K., Caffin, M., Watt, S., & Livesley, S. J. (2021). International approaches to protecting and retaining trees on private urban land. Journal of Environmental Management, 285, 112081. https://doi.org/10.1016/j.jenvman.2021.112081 Orlandini, S., Vanos, J. K., Matzarakis, A., Massetti, L., & Petralli, M. (2017). Urban forestry and microclimate. In F. Francesco, C. Konijnendijk van den Bosch, & Fini (Eds.), Urban forestry and microclimate (pp. 96–111). Routledge. https://doi.org/10.4324/9781315627106-7 Palinkas, L. A., Horwitz, S. M., Green, C. A., Wisdom, J. P., Duan, N., & Hoagwood, K. (2015). Purposeful Sampling for Qualitative Data Collection and Analysis in Mixed Method Implementation Research. Administration and Policy in Mental Health and Mental Health Services Research, 42(5), 533–544. https://doi.org/10.1007/s10488-013-0528-y Paschalis, A., Chakraborty, T., Fatichi, S., Meili, N., & Manoli, G. (2021). Urban Forests as Main Regulator of the Evaporative Cooling Effect in Cities. AGU Advances, 2(2), e2020AV000303. https://doi.org/10.1029/2020AV000303 Pauleit, S., Ennos, R., & Golding, Y. (2005). Modeling the environmental impacts of urban land use and land cover change—A study in Merseyside, UK. Landscape and Urban Planning, 71(2–4), 295–310. https://doi.org/10.1016/J.LANDURBPLAN.2004.03.009 150 Peckham, S. C., Duinker, P. N., & Ordóñez, C. (2013). Urban forest values in Canada: Views of citizens in Calgary and Halifax. Urban Forestry & Urban Greening, 12(2), 154–162. https://doi.org/10.1016/j.ufug.2013.01.001 Pincetl, S., Gillespie, T., Pataki, D. E., Saatchi, S., & Saphores, J.-D. (2013). Urban tree planting programs, function or fashion? Los Angeles and urban tree planting campaigns. GeoJournal, 78(3), 475–493. https://doi.org/10.1007/s10708-012-9446-x Quigley, M. F. (2004). Street trees and rural conspecifics: Will long-lived trees reach full size in urban conditions? Urban Ecosystems, 7(1), 29–39. https://doi.org/10.1023/B:UECO.0000020170.58404.e9 Quinton, J. M., Duinker, P. N., Gallant, K. A., Steenberg, J. W. N., & Charles, J. D. (2019). To tree or not to tree: User and management perspectives of cemetery trees. Urban Forestry & Urban Greening, 43, 126385. https://doi.org/10.1016/j.ufug.2019.126385 Robinson, D. T., & Brown, D. G. (2009). Evaluating the effects of land‐use development policies on ex‐urban forest cover: An integrated agent‐based GIS approach. International Journal of Geographical Information Science, 23(9), 1211–1232. https://doi.org/10.1080/13658810802344101 Roman, L. A., Campbell, L. K., & Jordan, R. C. (2018). Civic Science in Urban Forestry: An Introduction. An Introduction. Rosenzweig, C., Solecki, W., Hammer, S. A., & Mehrotra, S. (2010). Cities lead the way in climate–change action. Nature, 467(7318), 909–911. https://doi.org/10.1038/467909a 151 Salter, J., Lu, Y., Kim, J. C., Kellett, R., Girling, C., Inomata, F., & Krahn, A. (2020). Iterative ‘what-if’ neighborhood simulation: Energy and emissions impacts. Buildings and Cities, 1(1), Article 1. https://doi.org/10.5334/bc.51 Säumel, I., Weber, F., & Kowarik, I. (2016). Toward livable and healthy urban streets: Roadside vegetation provides ecosystem services where people live and move. Environmental Science & Policy, 62, 24–33. https://doi.org/10.1016/J.ENVSCI.2015.11.012 Sethi, M., Lamb, W., Minx, J., & Creutzig, F. (2020). Climate change mitigation in cities: A systematic scoping of case studies. Environmental Research Letters, 15(9), 093008. https://doi.org/10.1088/1748-9326/ab99ff Shanahan, D. F., Fuller, R. A., Bush, R., Lin, B. B., & Gaston, K. J. (2015). The Health Benefits of Urban Nature: How Much Do We Need? BioScience, 65(5), 476–485. https://doi.org/10.1093/biosci/biv032 Shaw, A., Burch, S., Kristensen, F., Robinson, J., & Dale, A. (2014). Accelerating the sustainability transition: Exploring synergies between adaptation and mitigation in British Columbian communities. Global Environmental Change, 25, 41–51. https://doi.org/10.1016/J.GLOENVCHA.2014.01.002 Sheppard, S. R. J., Konijnendijk van den Bosch, C., Croy, O., Macias, A., & Barron, S. (2017). Urban forest governance and community engagement. In F. Francesco, C. Konijnendijk van den Bosch, & A. Fini (Eds.), Routledge Handbook of Urban Forestry (1st ed., pp. 205–221). Routledge. Sheppard, S. R. J., Shaw, A., Flanders, D., Burch, S., Wiek, A., Carmichael, J., Robinson, J., & Cohen, S. (2011). Future visioning of local climate change: A 152 framework for community engagement and planning with scenarios and visualisation. Futures, 43(4), 400–412. https://doi.org/10.1016/j.futures.2011.01.009 Sinclair, A. J., Diduck, J., & Duinker, P. N. (2014). Elicitation of urban forest values from residents of Winnipeg, Canada. Canadian Journal of Forest Research, 44(8), 922–930. https://doi.org/10.1139/cjfr-2014-0016 Smith, T. B. (1973). The policy implementation process. Policy Sciences, 4(1973), 197–209. Spyridaki, N.-A., & Flamos, A. (2014). A paper trail of evaluation approaches to energy and climate policy interactions. Renewable and Sustainable Energy Reviews, 40, 1090–1107. https://doi.org/10.1016/j.rser.2014.08.001 Staley, D. C. (2012). Increasing Green Infrastructure in Compact Developments: Strategies for Providing Ecologically Beneficial Greenery in Modern, Urban-Built Environments. Journal of Heat Island Institute International, 7–2. Statistics Canada. (2019, February 20). Population and Dwelling Count Highlight Tables, 2016 Census. https://www12.statcan.gc.ca/census-recensement/2016/dp-pd/hlt-fst/pd-pl/Table.cfm?Lang=Eng&T=301&S=3&O=D#details-panel2 Statistics Canada. (2022, February 9). Census Profile, 2021 Census of Population. https://www12.statcan.gc.ca/census-recensement/2021/dp-pd/prof/index.cfm?Lang=E Steenberg, J. W. N., Duinker, P. N., & Charles, J. D. (2013). The neighbourhood approach to urban forest management: The case of Halifax, Canada. Landscape 153 and Urban Planning, 117, 135–144. https://doi.org/10.1016/j.landurbplan.2013.04.003 Steenberg, J. W. N., Millward, A. A., Nowak, D. J., Robinson, P. J., & Ellis, A. (2017). Forecasting Urban Forest Ecosystem Structure, Function, and Vulnerability. Environmental Management, 59(3), 373–392. https://doi.org/10.1007/s00267-016-0782-3 Steenberg, J. W. N., Robinson, P. J., & Millward, A. A. (2018). The influence of building renovation and rental housing on urban trees. Journal of Environmental Planning and Management, 61(3), 553–567. https://doi.org/10.1080/09640568.2017.1326883 Stevens, M. R., & Senbel, M. (2017). Are municipal land use plans keeping pace with global climate change? Land Use Policy, 68, 1–14. https://doi.org/10.1016/j.landusepol.2017.07.026 Stone, B. (2007). Urban and rural temperature trends in proximity to large US cities: 1951–2000. International Journal of Climatology, 27(13), 1801–1807. https://doi.org/10.1002/joc.1555 Stovin, V. R., Jorgensen, A., & Clayden, A. (2008). Street Trees and Stormwater Management. Arboricultural Journal, 30(4), 297–310. https://doi.org/10.1080/03071375.2008.9747509 Tan, P. Y., Wang, J., & Sia, A. (2013). Perspectives on five decades of the urban greening of Singapore. Cities, 32, 24–32. https://doi.org/10.1016/j.cities.2013.02.001 154 The White House. (2022, August 17). FACT SHEET: Inflation Reduction Act Advances Environmental Justice. The White House. https://www.whitehouse.gov/briefing-room/statements-releases/2022/08/17/fact-sheet-inflation-reduction-act-advances-environmental-justice/ The World Bank. (2022, October 6). Urban Development. The World Bank. https://www.worldbank.org/en/topic/urbandevelopment/overview Thompson, C. (2020, October 9). Trees Are Time Machines. The Atlantic. https://www.theatlantic.com/science/archive/2020/10/trees-need-be-future-proofed/616660/ Tree Canada. (2019). Canadian Urban Forest Strategy 2019-2024. https://treecanada.ca/wp-content/uploads/2018/10/TC-CUFS-2019-2024-Eng-1.pdf Troy, A. R., Grove, J. M., O’Neil-Dunne, J. P. M., Pickett, S. T. A., & Cadenasso, M. L. (2007). Predicting Opportunities for Greening and Patterns of Vegetation on Private Urban Lands. Environmental Management, 40(3), 394–412. https://doi.org/10.1007/s00267-006-0112-2 Turner-Skoff, J. B., & Cavender, N. (2019). The benefits of trees for livable and sustainable communities. PLANTS, PEOPLE, PLANET, 1(4), 323–335. https://doi.org/10.1002/ppp3.39 Ulrich, R. S. (1984). View Through a Window May Influence Recovery from Surgery. Science, 224(4647), 420–421. https://doi.org/10.1126/science.6143402 United Nations. (2019). World Urbanization Prospects 2018: Highlights (pp. 38–38). https://population.un.org/wup/Publications/Files/WUP2018-Highlights.pdf 155 Urwin, K., & Jordan, A. (2008). Does public policy support or undermine climate change adaptation? Exploring policy interplay across different scales of governance. Global Environmental Change, 18(1), 180–191. https://doi.org/10.1016/J.GLOENVCHA.2007.08.002 van den Berg, M., Wendel-Vos, W., van Poppel, M., Kemper, H., van Mechelen, W., & Maas, J. (2015). Health benefits of green spaces in the living environment: A systematic review of epidemiological studies. Urban Forestry & Urban Greening, 14(4), 806–816. https://doi.org/10.1016/j.ufug.2015.07.008 van den Bosch, M. (2017). Impacts of urban forests on physical and mental health and wellbeing. In F. Ferrini, C. Konijnendijk van den Bosch, & A. Fini (Eds.), Routledge Handbook of Urban Forestry (1st Edition, pp. 82–95). Routledge. van der Jagt, A. P. N., & Lawrence, A. (2019). Local government and urban forest governance: Insights from Scotland. Scandinavian Journal of Forest Research, 34(1), 53–66. https://doi.org/10.1080/02827581.2018.1532018 Vancouver Board of Parks and Recreation. (2020). Urban Forest Strategy Update (p. 7). Vancouver Board of Parks and Recreation. https://parkboardmeetings.vancouver.ca/2020/20201207/REPORT-UrbanForestStrategyUpdate-20201207.pdf Vasileiou, K., Barnett, J., Thorpe, S., & Young, T. (2018). Characterising and justifying sample size sufficiency in interview-based studies: Systematic analysis of qualitative health research over a 15-year period. BMC Medical Research Methodology, 18(1), 148. https://doi.org/10.1186/s12874-018-0594-7 156 Viguié, V., & Hallegatte, S. (2012). Trade-offs and synergies in urban climate policies. Nature Climate Change, 2(5), Article 5. https://doi.org/10.1038/nclimate1434 Vogt, J., Hauer, R., & Fischer, B. (2015). The Costs of Maintaining and Not Maintaining the Urban Forest: A Review of the Urban Forestry and Arboriculture Literature. Arboriculture & Urban Forestry, 41, 293–323. https://doi.org/10.48044/jauf.2015.027 Williams, K., Joynt, J. L. R., & Hopkins, D. (2010). Adapting to Climate Change in the Compact City: The Suburban Challenge. Built Environment, 35(1), 105–115. Wolch, J. R., Byrne, J., & Newell, J. P. (2014). Urban green space, public health, and environmental justice: The challenge of making cities ‘just green enough.’ Landscape and Urban Planning, 125, 234–244. https://doi.org/10.1016/J.LANDURBPLAN.2014.01.017 Wolf, K. L. (2017). Social aspects of urban forestry and metro nature. In F. Ferrini, C. Konijnendijk van den Bosch, & A. Fini (Eds.), Routledge Handbook of Urban Forestry (1st Edition, pp. 65–81). Routledge. Wu, Z., Chen, R., Meadows, M. E., Sengupta, D., & Xu, D. (2019). Changing urban green spaces in Shanghai: Trends, drivers and policy implications. Land Use Policy, 87, 104080. https://doi.org/10.1016/j.landusepol.2019.104080 Young, R. F. (2011). Planting the Living City. Journal of the American Planning Association, 77(4), 368–381. https://doi.org/10.1080/01944363.2011.616996 Yumagulova, L., & Vertinsky, I. (2017). Climate Change Adaptation and Flood Management in Metro Vancouver Regional Area: Can an Exercise in Herding 157 Cats be Successful? Journal of Sustainable Development of Energy, Water and Environment Systems, 5(2), 273–288. https://doi.org/10.13044/j.sdewes.d5.0149 Zhao, J., Chen, S., Jiang, B., Ren, Y., Wang, H., Vause, J., & Yu, H. (2013). Temporal trend of green space coverage in China and its relationship with urbanization over the last two decades. Science of The Total Environment, 442, 455–465. https://doi.org/10.1016/j.scitotenv.2012.10.014 158 Appendices Appendix A.1 – List of climate change and urban forestry policies reviewed Municipality Climate Change Policy Urban Forestry Policy Toronto 1. TransformTO: Climate Action for a Healthy, Equitable and Prosperous Toronto (2017) 2. Toronto’s First Resilience Strategy Sustaining and Expanding the Urban Forest: Toronto’s Strategic Forest Management Plan 2012-2022 (2013) Montréal 1. Climate Change Adaptation Plan for the Montréal Urban Agglomeration 2015-2020 Adaptation Measures 2. Climate Change Adaptation Plan for the Montréal Urban Agglomeration 2015-2020 Report (2017) Le Plan d’Action Canopée (2012) Calgary Climate Resilience Strategy (2018) N/A Ottawa 1. Climate Change Master Plan (2019) 2. New Official Plan: Climate Adaptation and Resiliency (2019) Putting Down Roots for the Future: City of Ottawa Urban Forest Management Plan 2018-2037 (2017) Edmonton Climate Resilient Edmonton: Adaptation Strategy and Action Plan (2018) Urban Forest Management Plan: Edmonton's Urban Forest - Taking root Today for a Sustainable Tomorrow (2012) Mississauga Climate Change Action Plan (2019) Urban Forest Management Plan (2014) Winnipeg Winnipeg’s Climate Action Plan (2018) N/A Vancouver Climate Emergency response report (2020) Climate Change Adaptation Strategy (2012, updated in 2018) Urban Forest Strategy (2018) Brampton Climate Change Master Plan 2020-2030 of the Region of Peel (2019) Grow Green Environmental Master Plan (2014) Hamilton Taking Action on Climate Change in Hamilton – A Community Plan (2015) Hamilton Urban Forest Strategy Work Plan & Draft Goals and Actions (for stakeholder workshop) (2019) Québec 2013−2020 Climate Change Action Plan of the Province of Québec (2012) Place aux arbres: Vision de l’arbre 2015-2025 (Urban Forest Vision) Surrey Community Climate Action Strategy: Reducing Emissions and Adapting to Climate Change Shade Tree Mgmt Strategy (2016) Laval BILAN 2016-2017-2018 Adaptation Aux Changements Climatiques de la Ville de Laval (2014) POLITIQUE DE L’ARBRE (Tree Policy) (2016) Halifax 1. Corporate Plan to Reduce Greenhouse Gas Emissions 2012-2020 (2011) 2. Community Action Guide to Climate Change and Emergency Preparedness (2010) Urban Forest Master Plan (2013) 159 3. HalifACT 2050 (2020) London Community Energy Action Plan (2014) Urban Forest Strategy (2014) Markham Markham’s Greenprint Sustainability Plan (2011) N/A Vaughan Community Climate Action Plan For Reducing Community Greenhouse Gas Emissions (2014) EXPANDING THE URBAN FOREST – one TREE at a time (November 2012) Gatineau N/A 1. Trees and Woodland Mgmt Plan for Gatineau 2. Tree Canopy Assessment for National Capital Region (2019) Saskatoon LOCAL ACTIONS: Saskatoon’s Adaptation Strategy: Part One & Part Two (2019) Saskatoon’s Urban Forest: A guide to urban forest services (Urban Forest Management Plan under development) (2019) Green Infrastructure Strategy - Update (2017) Longueuil DÉCLARATION DE LA VILLE DE LONGUEUIL CONCERNANT LA RÉDUCTION DES GES (2020) 1. Urban Forest Policy (1990) 2. L’arbre Infrastructure verte: Une politique qui prend racine (Tree Policy) (June 2018) 160 Appendix B.1 – Interview Script Hi XXX (participant’s name), how are you? Thanks so much for agreeing to participate in our research project. Before we start, do you have any questions for us? Thanks for the questions! If you agree, I’ll start recording from this point onwards. 1. Could you briefly tell me your current position and responsibilities? Would you consider yourself an urban forester, urban planner, landscape architect, arborist, or something else? 2. How many years have you been working in this field? 3. Which policies in the city are most relevant to your work currently? What policies are you most familiar with? 4. XX (City’s name, e.g. Vancouver) is promoting compact, complete and walkable neighbourhoods (according to e.g. the Climate Emergency Action Plan). a. How do you see urban forests fitting into these goals? b. Compact, complete, walkable neighbourhoods typically entail higher density development, with larger buildings and less green space on private lands. What do you think the City should do to protect and enhance urban forests while building compact, complete, walkable neighbourhoods? 5. In your work, have you encountered any unintended positive results of: a. The municipal urban forestry policy and associated regulations and targets (if the interviewee works in the field of urban forestry) b. The city’s policies and regulations in support of compact, complete, walkable communities (if the interviewee works in the fields of urban planning and development) 161 c. climate policies (if the interviewee works in the field of climate action and sustainability) 6. Have you seen any unintended negative results of: a. The municipal urban forestry policy and associated regulations and targets (if the interviewee works in the field of urban forestry) b. The city’s policies and regulations in support of compact, complete, walkable communities (if the interviewee works in the fields of urban planning and development) c. climate policies (if the interviewee works in the field of climate action and sustainability) 7. Are there any synergies and connections among urban forest, urban planning, and climate policies? 8. How about conflicts and trade-offs? Do you see any conflicts and trade-offs among urban forest, urban planning, and climate action policies? 9. [if not mentioned/answered previously] Are you aware of any land development regulations that make it difficult (or challenging) to achieve urban forest /greening actions, particularly preserving existing trees and planting new trees? 10. Do you have any solutions or suggestions on avoiding or resolving the conflicts you have mentioned between policies? 11. Are there anyone else you would recommend us to talk to regarding this study? That’s all the questions I have for you. Is there anything else you would like to add? Do you have any other questions or comments for us? 162 We will share a brief summary of the key findings once the study is completed. Thanks a lot again for your time today! Have a great day! Goodbye! 163 Appendix B.2 – Synergies with urban forestry policy implementation identified by participants, classified by process or outcomes Areas and Types of Synergies Synergies # of participants (Re)development: Policy Synergies (n=3) Sidewalk improvement or other tree planting requirements for (re)development projects in bylaws or community plans & street tree planting requirements in urban forestry policies 2 Goal of creating a safe and connected active transportation networks in transportation policies & street tree planting and management goals in urban forestry policies 1 (Re)development: Implementation Synergies (n=8) Improve street network for active transportation & increase tree planting along streets 2 Increase and improve public realm during (re)development & create tree-friendly space 2 Implement traffic calming programs & plant more street trees 2 Include soil details on streets as outlined by the engineering guidelines & improve street tree management 1 Fulfill sidewalk improvements through replacement planting & plant more trees and increase urban forest canopy 1 Fulfill tree replacement requirements for (re)development projects & plant more private trees to maintain or increase urban tree canopy 1 Implement neighbourhood (re)development plans & create more tree planting opportunities 1 (Re)development: Outcome Synergies (n=1) Preserved viewscape as a result of the zoning bylaws & retained trees even in the denser parts of the city 1 Climate Action: Policy Synergies (n=5) Recognition of urban forests’ role in climate change adaptation in climate policies (e.g. managing stormwater and mitigation urban heat) 5 Integration of urban forests related goals (e.g., enhance naturalized area, green equity and biodiversity) in climate policies 4 164 Recognition of urban forests’ role in climate change mitigation in climate policies (e.g. sequestrating carbon and promoting active transportation) 2 Climate Action: Implementation Synergies (n=4) Implement urban forest related climate adaptation initiatives (e.g., planting trees for stormwater management and cooling) 3 Implement climate change mitigation initiatives to reduce reliance on fossil fuel vehicles & create more public space for trees 2 Climate Action: Outcome Synergies (n=1) Tree-based green infrastructure is installed for flood resilience & trees planted with green infrastructure installations 1 Infrastructure: Policy Synergies (n=1) Recognition and integration of trees in green infrastructure policies & tree planting goals for stormwater management in urban forestry policies 1 Infrastructure: Implementation Synergies (n=5) Enhance green infrastructure network & plant trees as part of green infrastructure installations 2 Maintain the storm sewage system & plant trees for stormwater management 2 Infrastructure: Outcome Synergies (n=2) Tree-based green infrastructure installed for flood resilience & trees planted with green infrastructure installations 2 Environmental Sustainability: Policy Synergies (n=4) Recognition and integration of urban forests in environmental sustainability policies (e.g., sustainability plan and biodiversity strategy) 4 Environmental Sustainability: Implementation Synergies (n=3) Promote and fulfill environment and sustainability goals and practices & plant more trees and create more green space 2 Promote and fulfill biodiversity goals & plant trees and enhance green infrastructure network 1 Environmental Sustainability: Outcome Synergies (n=1) Environmentally sustainable practices are conducted driven by the sustainability policies & trees are preserved, and lands are secured for tree planting during densification process 1 165 Appendix B.3 – Trade-offs with urban forestry policy implementation identified by participants, classified by process or outcomes Areas and Types of Trade-offs Trade-offs # of Participants (Re)development: Implementation Trade-offs (n=10) Increase density vs. retain existing trees and plant new trees 7 Increase flexibility on tree retention and planting requirements for (re)development projects vs. retain existing tree and plant new trees 5 Fulfill parking requirements for residential buildings vs. preserve appropriate space for trees 4 Plan and approve an increasing number of (re)development projects (e.g., pave more ground) vs. maintain tree health and ecosystem services 4 Plant trees on structures (e.g. building roofs and raised planters) vs. increase urban forest longevity 2 Plant trees on building roofs vs. increase equity in accessing trees and associated benefits 2 Ease into private land to increase public realm vs. preserve appropriate space and soil volume for street trees planted in the easement area 2 Allow houses to be built close to riparian corridors vs. reduce urban forest risks 1 (Re)development: Outcome Trade-offs (n=9) Increased density vs. appropriate space reserved for trees 5 Increased developments overall vs. retention of existing trees 4 More flexibility on tree retention and planting requirements for (re)development projects vs. retention of existing trees 3 Trees planted on structures vs. maintained or enhanced tree health 2 Building materials for energy saving purposes used vs. maintained or enhanced tree health 1 Infrastructure: Implementation Trade-offs Install ground-level grey infrastructure vs. reserve appropriate space for trees: ● Automobile infrastructure: driveways and ground 8 166 (n=10) parking space (6) ● Active transportation infrastructure: bike lanes and sidewalks (3) ● Transit infrastructure: e.g., bus stops (2) ● Street space in general (2) ● Lighting facility (1) ● Public service infrastructure: e.g., fire halls (1) Install infrastructure (in general) vs. reserve appropriate space for trees 6 Install underground infrastructure vs. reserve appropriate space for tree roots: ● Underground utilities (e.g., high-pressure gas lines, sewer pipes, and water mains) (3) ● Automobile infrastructure: underground parking (1) 4 Install overhead infrastructure (powerlines) vs. reserve appropriate space for tree crowns 1 Infrastructure: Outcome Trade-offs (n=9) Installed infrastructure (in general) vs. appropriate space reserved for trees 3 Installed automobile infrastructure (driveways and parking) vs. appropriate space reserved for trees 3 Installed active transportation infrastructure (bike lanes and sidewalks) vs. appropriate space reserved for trees 2 Installed water and electricity infrastructure vs. appropriate space reserved for trees 2 Green infrastructure projects with no trees vs. retention of existing trees 1 Installed ornamental lights vs. maintained or enhanced tree health 1 Urban forest management: Implementation Trade-offs (n=2) Enhance urban forest species diversity vs. prioritize to plant species that the public prefers 1 Maintain urban trees vs. plant urban trees (e.g., replace removed street trees) 1 Manage wildfire risks vs. plant trees where possible 1 167 Appendix C.1 – Key assumptions on tree mortality rate, species mix, tree size and tree spacing for the moderate-effort interventions and the ambitious-effort interventions in 2050 Location of Trees Moderate-Effort Interventions (2050） Ambitious-Effort Interventions (2050) Mortality Rate Private 4.6% 3.6% Street 2.6% 1.6% Park 2.2% 1.2% Tree Species and Size Private ● Follow the current species choice of the City of Vancouver ● Large = 2%; Medium = 48%; Small = 50% ● Plant climate-adapted species only ● Large = 2%; Medium = 54%; Small = 44% Street ● Follow the current species choice of the City of Vancouver ● Large 21%; medium 37%; small 42% ● Plant climate-adapted species1 only ● Large = 42%; Medium = 58%; Small = 0% Park ● Follow the current species choice of the City of Vancouver ● Large 45%; medium 50% small 5% ● Plant climate-adapted species1 only ● Existing parks: Large = 45%; Medium = 50%; Small = 5% ● New park: Large = 50%; Medium = 50% Tree Spacing Private ● 1.5m from any principal building on/adjacent to the site ● 2.5m from any other tree on/adjacent to the site ● 1.5m from any principal building on/adjacent to the site ● 2.5m from any other tree on/adjacent to the site Street ● Large trees: 11m ● Medium trees: 10m ● Small trees: 9.5m Regular streets: ● Same as the moderate-effort interventions Blue-green streets: ● Large trees 10m ● Medium trees 9.5m ● Small trees 9m 168 Park ● 1.5m from any principal building on/adjacent to the site ● No planting on sport field ● 4m spacing between coniferous trees ● 1.5m from any principal building on/adjacent to the site ● No planting on sport field ● 4m spacing between coniferous trees
Thesis/Dissertation
eng
Forestry
Vancouver : University of British Columbia Library
Attribution-NonCommercial-NoDerivatives 4.0 International
Graduate
Sheppard, S. R. J. (Stephen Richard John), 1952-
Nesbitt, Lorien
Integrating urban forestry into compact, climate resilient cities : policies and pathways
Text