A Scoping Review of Urban Planning Decision Support Tools and Processes That Account for the Health, Environment, and Economic Benefits of Trees and Greenspace

Compelling evidence shows that trees and greenspaces positively impact human well-being and the environment and offer economic benefits. Nevertheless, there exists a knowledge gap regarding the extent to which this evidence is efficiently incorporated into existing urban planning decision-making processes. This scoping review identified the extent to which urban planning decision-making frameworks, models, and tools consider the health, environmental, and economic benefits of trees and greenspace. Out of 28 reviewed studies, 11 (39%) reported on frameworks, models, and tools that take into account the health, environmental, and economic dimensions of trees and greenspace. Additionally, seven studies provided comprehensive coverage of at least one of the three key dimensions. However, none of the decision support frameworks, models, or tools comprehensively integrated all three dimensions, with only two tools (7%) scoring above 50% (five or more out of nine) in terms of comprehensiveness. This review highlights the urgent need to incorporate the true economic and monetary values of the health and environmental benefits of trees and greenspace to inform urban development decision making.


Introduction
The intricate linkages between urban planning, greenspace, trees, health, and the environment are evident through the recognition that health is influenced by a wide array of factors, encompassing social, economic, political, cultural, and environmental aspects, collectively referred to as the social determinants of health [1].Likewise, the environment is significantly shaped by external factors and decisions that extend beyond traditional environmental boundaries [2].Urban planning, for example, can transform the environment we inhabit by providing access to trees and greenspace, which influences physical health, mental well-being, and ecosystems, thus altering the relationship between overall human health and the environment.This highlights the need for "healthy urban planning processes" that create a balance between social, environmental, and economic priorities while considering the potential implications of decisions on both human health and the environment [3].
In urban planning and design, the terms "trees" and "greenspace" are often used interchangeably and are sometimes considered together or defined inconsistently, but they have different characteristics [4][5][6].For instance, trees are generally less fragmented and form larger patches than shrubs, while grass typically has medium fragmentation but forms the largest patches and is more interconnected than trees and shrubs [7].In this context, the term "greenspace" is used to encompass any area of land that is covered with vegetation, including trees, shrubs, grasses, and other types of vegetation found in urban landscapes such as parks, gardens, backyards, streetscapes, forests, and even rooftops.
Evidence supporting the health and environmental benefits of urban greening has grown significantly in recent years [8,9].Greenspace offers a range of ecosystem services, such as pollutant reduction, temperature regulation, and the control of air and sound pollution [10].Greenspace also plays a vital role in replenishing groundwater, recycling and conserving water, averting surface runoff and flooding, preventing soil erosion, and serving as habitats while fostering biodiversity [8,11].Furthermore, trees and greenspace contribute significantly to environmental well-being, including carbon sequestration, energy conservation, and the reduction in carbon emissions [12].Trees provide significant erosion and flood mitigation benefits due to their intricate root systems, height, and extensive canopies that facilitate infiltration of rainwater into the ground, interception of rainwater, and storage of rainwater within branches, trunks, and leaves, thereby reducing the amount of runoff that reaches the ground and the amount of surface runoff [13,14].These ecosystem services, in turn, translate into health benefits by encouraging physical activities such as walking and cycling; fostering social interaction; and preventing diseases that might otherwise arise [15].Notably, numerous studies have established positive correlations between exposure to greenspace and enhanced mental well-being, encompassing improvements in attention, mood, and cognitive functioning [16][17][18][19][20].In addition, access to greenspace has been linked to reduction in crime [21] and increased social cohesion and social capital [22].Research has also demonstrated various physical health benefits, including reduced risk of cardiovascular diseases [23], obesity [24], heart rate, and diastolic blood pressure [18,25].
Quantifying the mental health benefits associated with trees and greenspace remains a challenge despite a growing body of research that suggests that trees and greenspace can positively impact mental health [26][27][28].For instance, one study found that individuals residing in neighborhoods with greater tree cover exhibited lower rates of depression and anxiety [29].Another study revealed that spending time in nature can effectively reduce stress levels and enhance mood [30].However, quantifying the mental health benefits of trees and greenspace remains challenging due to methodological difficulties with establishing causal relationships between exposure to trees and greenspace and mental health outcomes [31].Isolating the effects of trees and greenspace from other factors influencing mental health, such as social factors, economic factors, and personal characteristics, presents a significant challenge.
The advantages in terms of health and the environment can be transformed into economic benefits through an increase in productivity (as healthier individuals are generally more productive) and a decrease in healthcare and environmental costs [12].Prevention of heat-related illnesses during extreme heatwaves leads to fewer ambulance calls and visits to the emergency department, resulting in lower expenses associated with treatment and care [12,32].Similarly, the carbon sequestration potential of trees and greenspace contributes to mitigating climate change, resulting in fewer instances of wildfires and floods, thereby reducing property damage and the costs of emergency services [33].The heat regulation function of trees and greenspace can also lead to savings in energy consumption through a reduced need for air-conditioning [34].Additionally, trees and greenspace can make a direct economic contribution by attracting tourists and improving environmental quality, which, in turn, increases property values [35].
Despite compelling evidence supporting the positive impacts of trees and greenspace on health, the environment, and the economy, there exists a notable gap in translating this evidence into urban planning and development decision-making processes.Some studies have noted that traditionally, the decision-making landscape has not adequately considered health and environmental benefits when making urban planning decisions, with public health and environmental issues typically falling under the responsibility of ecologists and health professionals [15,36].The majority of prior research has concentrated on formulating frameworks that link urban planning decision-making processes with the impact on regulating ecosystem services.These studies consistently pointed out that regulating ecosystem services is often overlooked in current decision-making processes [37,38].While these investigations generally center on ecosystem services, the significance of trees and greenspaces for these services [39] prompts the extension of the same principle to encompass trees and greenspace.Consequently, trees and greenspace are frequently seen as liabilities rather than assets, relegating them to low priority in urban planning projects, particularly when resources are limited [15].This results in a decline in both the quantity and quality of trees and greenspace over time [12], leading to urban environments that expose people to greater health risks and environmental degradation.However, there is a growing recognition of the importance of integrating health and environmental considerations into urban planning processes, programs, and projects [40].
This status quo underscores the critical need for urban planning decision-making processes that take into account the full range of benefits that greenspace provides, including the health, the environment, and the economic benefits.Yet, there is a gap in our understanding regarding the degree to which existing urban planning decision-making processes, including frameworks, models, and tools used, integrate these interconnected benefits.In this scoping review, we systematically identified and reviewed relevant studies that examine existing urban planning decision support frameworks, models, and tools, with the specific aim of evaluating the extent to which current urban planning decision-making processes incorporate health, environmental, and economic benefits of trees and greenspace.

Materials and Methods
This scoping review was conducted in accordance with the JBI methodology for scoping reviews [41].The Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist was used to guide the reporting [42].

Review Questions
The scoping review procedure, including the search strategy as well as the screening and selection criteria, was guided by the following review questions: • To what extent do current decision-making processes used in urban planning projects take account the health and environmental benefits of exposure to trees and greenspace?• To what extent do these decision-making processes incorporate the economic valuation of the environmental and/or health benefits of trees and greenspace?

Search Strategy
A literature search was conducted in four databases: PubMed, Scopus, Public Health Database, and Web of Science.Search terms were identified under three key concepts, "green space", "decision-making process", and "urban planning", which were used to construct the logic grids.Relevant subject headings and MeSH terms for each database were identified, and the Boolean operators "AND" and "OR" were used to construct search strings.The development of the search strategy and logic grids was conducted in consultation with a research librarian (Appendix A).The grey literature search was conducted using Google Advanced Search.In particular, the websites for the relevant government departments from each Australian state and territory were searched, as well as publications by international bodies such as the World Health Organization, the World Bank, and the United Nations.Search results were imported into Covidence systematic review software, Veritas Health Innovation, Melbourne, Australia, where duplicates were identified and removed.

Screening and Selection
Based on the review questions, the primary concept of this review was decisionmaking processes that address health, environmental, and/or economic benefits of trees and greenspace.Based on this, records that fulfill all the following selection criteria were considered eligible for the review: records that (1) discuss decision-making frameworks, models, or tools; (2) incorporate at least one of the health, environmental, and/or economic benefits of trees and greenspace; and (3) are within the context of urban planning.Studies that did not consider at least one element of trees and greenspace benefits, those that discuss blue spaces, and those that focus solely on the health or environmental benefits of trees and greenspace, without any relevance to urban planning and decision support processes were excluded.An abstract and title screening was conducted using the inclusion and exclusion criteria.Each record was double-screened by two independent reviewers (C.B. and Y.T.), and any discrepancies were resolved through discussion, with inputs from a third reviewer (C.W. or V.S.) when necessary.Subsequently, full texts were assessed, and those records that met the inclusion criteria progressed to the data extraction stage.The selection and screening process was documented using a PRISMA flow diagram [42].

Data Extraction and Synthesis
Information from the records included in the scoping review was gathered using a data extraction template developed by the reviewers (Table A7 in Appendix B).The data extraction template comprised various fields regarding the study characteristics, such as year of publication and study area.Moreover, the template includes specific information about the decision support frameworks, models, and tools.This encompassed their creation and development process, strengths, limitations, and whether they considered health, environmental, and economic aspects of trees and greenspace.
After extracting the data, we synthesized the information and categorized the records into three primary dimensions: health, environmental, and economic, either individually or in combination.Refer to Figure 1 for a conceptual framework that serves as a guideline to assess the extent to which the identified decision support frameworks, models, and tools comprehensively incorporate any of these benefits.
The data synthesis involved scoring each literature record from 0 to 9, based on how well the reported decision-making tools and frameworks integrated health, environmental, and economic benefits of trees and greenspace with reference to the elements outlined in Figure 1 as a framework.A total score out of 9 was calculated by summing the scores across three dimensions (health, environment, economics), each rated from 0 to 3. A score of 0 in any dimension indicated no incorporation of associated benefits.For health and environmental dimensions, a score of 1 meant integration of one element (e.g., improved social capital or carbon sequestration), while a score of 2 indicated integration of two or more elements without comprehensive coverage.A score of 3 was awarded for comprehensive integration of multiple aspects of health or environmental benefits.As for the economic dimension, a score of 1 was assigned if the record addressed one or more direct economic benefits of trees and greenspace (such as tourism or property value), without considering any economic benefits linked to health or the environment.A score of 2 was assigned if it included at least one element of the economic values associated with health (e.g., avoided treatment costs of heat-related illnesses,) or environmental benefits (monetary value of air pollution removal) without factoring in any direct economic benefits.If it incorporated at least one element of the direct economic values along with at least one element pertaining to either health or environmental benefits, the study received a score of 3.

Search Results
The initial database and grey literature searches retrieved a total of 358 records.After removing 31 duplicates in Covidence, 327 records went through title and abstract screening, of which 66 were retained for full text review.After full text review and screening, we ultimately included 28 records in the final review and synthesis.The remaining records were excluded for various reasons.Some did not encompass at least one aspect related to the benefits of trees and greenspace, or they focused on urban planning decision-making processes unrelated to trees or greenspace.Additionally, some solely concentrated on the health or environmental benefits of trees and greenspace without any relevance to urban planning and decision support processes.Others failed to present urban planning frameworks, models, or tools, or these frameworks and tools had already been addressed in another record included in the review.This process can be viewed in the PRISMA diagram in Figure 2.

Search Results
The initial database and grey literature searches retrieved a total of 358 records.After removing 31 duplicates in Covidence, 327 records went through title and abstract screening, of which 66 were retained for full text review.After full text review and screening, we ultimately included 28 records in the final review and synthesis.The remaining records were excluded for various reasons.Some did not encompass at least one aspect related to the benefits of trees and greenspace, or they focused on urban planning decision-making processes unrelated to trees or greenspace.Additionally, some solely concentrated on the health or environmental benefits of trees and greenspace without any relevance to urban planning and decision support processes.Others failed to present urban planning frameworks, models, or tools, or these frameworks and tools had already been addressed in another record included in the review.This process can be viewed in the PRISMA diagram in Figure 2.
Figure 3 shows the number of relevant publications over time.Out of the 28 studies included in this review, only 2 (7%) were published prior to 2012 [43,44].From 2012 to 2017, the annual publication count ranged from zero to two studies, while between 2018 and 2023, this increased to three to five studies per year, except for 2020 when no studies were published.A significant portion of these studies (71%) emerged within the last six years, indicative of a growing trend in both publications and research interest regarding the integration of trees and greenspace benefits into urban planning decision-making processes.The majority of these studies were from developed nations (71%), with a smaller proportion carried out in developing nations (29%) (Appendix B). Figure 3 shows the number of relevant publications over time.Out of the 28 studies included in this review, only 2 (7%) were published prior to 2012 [43,44].From 2012 to 2017, the annual publication count ranged from zero to two studies, while between 2018 and 2023, this increased to three to five studies per year, except for 2020 when no studies were published.A significant portion of these studies (71%) emerged within the last six years, indicative of a growing trend in both publications and research interest regarding the integration of trees and greenspace benefits into urban planning decision-making processes.The majority of these studies were from developed nations (71%), with a smaller proportion carried out in developing nations (29%) (Appendix B).   Figure 3 shows the number of relevant publications over time.Out of the 28 studies included in this review, only 2 (7%) were published prior to 2012 [43,44].From 2012 to 2017, the annual publication count ranged from zero to two studies, while between 2018 and 2023, this increased to three to five studies per year, except for 2020 when no studies were published.A significant portion of these studies (71%) emerged within the last six years, indicative of a growing trend in both publications and research interest regarding the integration of trees and greenspace benefits into urban planning decision-making processes.The majority of these studies were from developed nations (71%), with a smaller proportion carried out in developing nations (29%) (Appendix B).

Health Benefits
Nearly two-thirds (64%) of the reviewed frameworks/models/tools (18 out of 28) incorporated at least one aspect of the health benefits associated with trees and greenspace.Nevertheless, only one of these, namely, the community health framework [56], provided a comprehensive integration of multiple aspects of health benefits, albeit without considering the environmental and economic dimensions of trees and greenspace benefits.Another tool that exclusively concentrated on health benefits was the WIND tool for assessing walkability [53].Importantly, the remaining 16 out of 18 frameworks/models/tools in this category extended their scope to incorporate at least one aspect of environmental or economic benefits alongside the health dimension.
None. (0) 4 Key: does not include any benefit from this column; includes some benefits from this column but is not comprehensive; tool comprehensively includes all relevant benefits from this column.

Health Benefits
Nearly two-thirds (64%) of the reviewed frameworks/models/tools (18 out of 28) incorporated at least one aspect of the health benefits associated with trees and greenspace.Nevertheless, only one of these, namely, the community health framework [56], provided a comprehensive integration of multiple aspects of health benefits, albeit without considering the environmental and economic dimensions of trees and greenspace benefits.Another tool that exclusively concentrated on health benefits was the WIND tool for assessing walkability [53].Importantly, the remaining 16 out of 18 frameworks/models/tools in this category extended their scope to incorporate at least one aspect of environmental or economic benefits alongside the health dimension.
None. (0) 4 Key: does not include any benefit from this column; includes some benefits from this column but is not comprehensive; tool comprehensively includes all relevant benefits from this column.

Health Benefits
Nearly two-thirds (64%) of the reviewed frameworks/models/tools (18 out of 28) incorporated at least one aspect of the health benefits associated with trees and greenspace.Nevertheless, only one of these, namely, the community health framework [56], provided a comprehensive integration of multiple aspects of health benefits, albeit without considering the environmental and economic dimensions of trees and greenspace benefits.Another tool that exclusively concentrated on health benefits was the WIND tool for assessing walkability [53].Importantly, the remaining 16 out of 18 frameworks/models/tools in this category extended their scope to incorporate at least one aspect of environmental or economic benefits alongside the health dimension.
includes some benefits from this column but is not comprehensive; None. (0) 4 Key: does not include any benefit from this column; includes some benefits from this column but is not comprehensive; tool comprehensively includes all relevant benefits from this column.

Health Benefits
Nearly two-thirds (64%) of the reviewed frameworks/models/tools (18 out of 28) incorporated at least one aspect of the health benefits associated with trees and greenspace.Nevertheless, only one of these, namely, the community health framework [56], provided a comprehensive integration of multiple aspects of health benefits, albeit without considering the environmental and economic dimensions of trees and greenspace benefits.Another tool that exclusively concentrated on health benefits was the WIND tool for assessing walkability [53].Importantly, the remaining 16 out of 18 frameworks/models/tools in this category extended their scope to incorporate at least one aspect of environmental or economic benefits alongside the health dimension.
tool comprehensively includes all relevant benefits from this column.

Environmental Benefits
The majority (26 out of 28, 93%) of examined frameworks/models/tools incorporated at least one environmental element of greenspace benefit.Among these, only six (21%) provided comprehensive coverage of multiple aspects of environmental benefits.While 21 (75%) of these extended their scope to encompass human health benefits and/or the economic values of trees and greenspace, in addition to environmental benefits, the remaining 5 incorporated benefits exclusively from the environment's perspective.This group included Hellwig's mathematical algorithm tool [62], a habitat suitability model [55], an urban heat island (UHI) assessment matrix [61], a performance index framework [63], and an integrated UCmap and GIS tool [60].A common limitation among these tools was their specificity, with four out of the five tools either tailored to address UHI or focused on the suitability of greenspace to support biodiversity.

Economic Benefits
In comparison to the health and environmental dimensions, a smaller proportion, specifically 16 out of 28 (57%) of the reviewed studies, reported frameworks/models/tools that encompassed at least one economic benefit of trees and greenspace.All of these frameworks/models/tools also considered at least one element from the health or environmental dimensions.However, only one, the I-Tree Eco tool [43], was deemed comprehensive (scoring 3 out of 3), as it integrated direct economic benefits as well as the economic values associated with the health benefits of trees and greenspace.Conversely, although another tool included multiple economic benefits in its framework, it did not quantify the monetary value of trees and greenspace benefits [46].

Comprehensiveness of the Tools and Frameworks
Among the 28 frameworks, models, and tools we reviewed, none comprehensively incorporated the health, environmental, and economic benefits of trees and greenspace.However, eleven of these tools and frameworks [43][44][45][46][48][49][50]59,65,66,69] did include elements from each of the three dimensions of greenspace benefits.In terms of comprehensiveness score, the overall assessment revealed that only two tools (7%) scored over 50% (5 or more out of 9).Furthermore, 13 tools (46%) scored 4 out of 9, while the remaining 13 tools (46%) scored 3 or less out of 9, as indicated in Table 1.
The two most comprehensive tools identified in this review are the I-tree [43] and the Melbourne Green Factor Tool [52].The i-Tree, developed by the USDA Forest Service in 2006, comprises a suite of software tools and applications for evaluating the economic and environmental benefits of urban trees and greenspace.It includes tools like i-Tree Eco, i-Tree Canopy, and i-Tree Hydro, which serve urban planners, arborists, and policy makers in managing greenspace.Specifically, i-Tree Eco, the tool of primary relevance to this scoping review, leverage species, city, pollution, and weather data as input to assess greenspace structure, environmental impact, and community value.The Melbourne Green Factor Tool is a web-based application specifically developed to assess private development proposals using a green factor score calculated based on the environmental and human health benefits of greenspace incorporated in the proposal.It calculates a green factor score considering the environmental and human health benefits of greenspace integrated into the proposals.A more in-depth analysis of the strengths and limitations of these two tools is provided in the Discussion section.

Discussion
The primary aim of this scoping review was to provide an overview of the existing urban planning decision-making processes and the extent to which these incorporate health, environmental, and economic benefits associated with trees and greenspace.The results show that none of the studies identified in this review from existing publications reported urban planning decision-making processes that sufficiently and comprehensively encompass health, environmental, and economic dimensions of tree and greenspace benefits.Out of the 28 tools and frameworks examined, 11 addressed at least one element from each of the three dimensions, and 6 provided comprehensive coverage of one of the three key dimensions.However, none of them managed to comprehensively integrate multiple aspects from all three dimensions.In fact, only two tools achieved a comprehensiveness score of 50% or more, with just one of them, i-Tree Eco Tool [26], comprehensively addressing two of the three major dimensions (environmental and economic dimensions).While several tools and frameworks do integrate multiple aspects of environmental benefits, there is still a noticeable gap when it comes to incorporating health and economic benefits of trees and greenspace.Most importantly, there is a significant gap in the current urban decisionmaking processes in terms of incorporating economic or monetary values associated with the health and/or environmental benefits of trees and greenspace, with only 1 out of the 28 reviewed tools and frameworks partly addressing this [26].In the sections below, we discuss the strengths and limitations of the two most comprehensive tools we identified in our review: i-Tree Tools [26] and the Melbourne Green Factor Tool [35].
The i-Tree Eco tool [26] uses input data (species, city, pollution, weather) to assess greenspace structure, environmental impact, and community value.It calculates benefits such as pollution reduction, health improvements, carbon storage/sequestration, hydrological effects, and energy savings.It also estimates the monetary values of the human health benefits associated with air pollution removal.These assessments can be made for both individual trees and greenspace canopy cover.Furthermore, i-Tree Eco can forecast future benefits for some aspects such as carbon sequestration, air quality, and hydrology.The tool has been adapted for use in several countries, including Australia.However, some aspects, such as energy use reduction and air pollution impacts, rely on US-specific data and may not be applicable elsewhere.Notably, i-Tree Eco has additional limitations, including its failure to comprehensively incorporate various health benefits of trees and greenspace beyond air pollution removal.It also does not account for mental health, physical health (cycling and walking, obesity, cardiovascular diseases), heat-related diseases, and social interaction benefits.Additionally, certain direct economic benefits of trees and greenspace such as increased property value and tourism-related gains are not included in its estimations.
The Melbourne Green Factor Tool, created in 2019, was founded upon a thorough review of the existing literature concerning the structural and functional aspects of greenspace.Its primary function is the evaluation and scoring of private building development proposals in Melbourne, with a focus on health and environmental benefits arising from the incorporation of greenspace within these proposals.This tool has several strengths, including its accessibility as a web-based, publicly available resource.It encompasses a wide spectrum of environmental benefits, such as mitigating urban heat islands, providing habitats, managing runoff, and supporting local food supplies.Moreover, it recognizes various health benefits associated with greenspace, including sharing opportunities for recreation, enhancing sense of place, fostering social cohesion, enhancing aesthetics, and contributing to mental well-being.The development of the tool follows a collaborative codesign and codevelopment approach, bringing together experts from various disciplines, including policy makers, sustainable building and landscape practitioners, software designers, and researchers.Notably, the tool is integrated into the urban planning process of the City of Melbourne.
However, it is essential to acknowledge several limitations of Melbourne Green Factor Tool.One notable limitation is that it does not account for the economic values associated with the health and environmental benefits or the direct economic benefits of trees and greenspace.It also relies on evidence available only up to 2019, making it incapable of adapting to new and evolving data.Furthermore, it primarily concentrates on assessing benefits of aerial greenspace, making it unsuitable for evaluating individual trees.Additionally, it falls short in quantifying physical health benefits, such as increased physical activities, cardiovascular health, and the prevention of obesity.Additionally, the tool does not take into account air purification benefits from greenspace, which was initially proposed but later removed during the peer-review process.The authors' rationale for this omission was based on the belief that air pollution is not a significant issue in countries like Australia.They also wanted to ensure that the tool does not imply that greenspace is meant to address air quality problems.Nonetheless, it is important to note that while Australia generally experiences low annual air pollution levels, during extreme episodes such as bushfires, some hotspot areas have recorded some of the world's highest pollution levels [71].Each year, air pollution is estimated to result in thousands of hospitalizations and premature deaths in Australia [72].
In summary, this scoping review has several important implications for urban planning decision-making processes.Firstly, this review underscores a substantial gap in current urban planning decision-making processes, indicating that despite the abundance of evidence and a supportive policy environment, the reviewed frameworks and tools do not adequately consider the health and environmental benefits offered by trees and greenspace.This is in line with previous studies that highlighted that ecosystem services are often overlooked within the context of urban planning decisions [37,38,49].This oversight suggests a potential failure to harness the positive impacts of trees and greenspace on public health and the environment in urban planning endeavors [73], leading to urban environments that can lead to significant inequalities and health problems [74].Secondly, this review emphasizes the scarcity of tools that incorporate the economic values associated with the health and environmental benefits of trees and greenspace.Consequently, under existing approaches, trees and greenspace are perceived as liabilities rather than recognized for their potential economic contributions [75].In the absence of such comprehensive tools, key urban planning decision makers, including planners, transport planners, engineers, and asset managers, often resort to financial decision-making tools to shape project structures and values.This could lead to urban planning decisions that prioritize the removal of trees and greenspace from projects in favor of economic viability.The overall implication is a call for the development and integration of comprehensive decision-making tools that consider the holistic benefits of trees and greenspace in urban planning.This includes tools that not only acknowledge the health and environmental advantages but also incorporate their economic values.Addressing this gap is crucial for creating sustainable, resilient, and people-centric urban environments.
It is essential to recognize certain potential challenges that must be considered in the future development of decision support tools for urban planning.One primary challenge is the quantitative assessment of certain benefits associated with trees and greenspace, such as mental health benefits.This challenge stems from methodological complexities, primarily due to the involvement of numerous confounding factors [31].Another challenge is that costs and benefits related to preserving and expanding green areas and trees are unevenly distributed among different groups and separated over time.For instance, in the case of new development projects, the expense of preserving existing trees is borne upfront by the developer or the buyer, while the benefits accrue to the local community residing in the neighborhood over many years, making preserving trees less attractive to the developer or buyer at the time.Similarly, the cost of removing a mature tree, though seemingly low, fails to account for the loss of multiple health and environmental benefits provided by these trees over time.For any future decision support frameworks, models, and tools in the context of urban planning, it is imperative to acknowledge and address these challenges to ensure effective adaptation and sustainable development.
Several recommendations for improving urban planning processes and decision making can be drawn from the findings of this study.Firstly, it is important to integrate health, environmental, and economic dimensions of tree and greenspace benefits into urban planning decision-making processes.This can be achieved through the development of comprehensive frameworks and tools that evaluate and quantify multiple benefits of trees and greenspace.This review identified two comprehensive tools-i-Tree Tools and the Melbourne Green Factor Tool-which could serve as valuable starting points for this endeavor.Secondly, urban planning authorities should prioritize improving the capacity and expertise of technical professionals to include health and environmental benefits in assessments of urban planning scenarios and options.Thirdly, urban planning authorities could implement mandatory requirements for urban developers to incorporate a comprehensive evaluation of the broader health and environmental benefits of trees and greenspace into their project design and implementation processes.Urban planners should develop urban design and transport planning guidelines that incorporate the latest evidence regarding health and environmental benefits of trees and greenspace.To address the uneven distribution of costs and benefits of trees and greenspace, urban planning authorities could implement policies that require developers to pay for part of cost of preserving existing trees or planting new trees in underserved communities.
Future research directions should include the development of more comprehensive frameworks and tools for evaluating the multifaceted benefits of trees and greenspace.Future research should prioritize developing methodologies for quantifying the mental health benefits of trees and greenspace.This includes addressing the methodological challenges associated with quantifying these benefits by conducting longitudinal studies.
The primary strength of this study lies in our utilization of a thorough and transparent search strategy, developed in collaboration with an experienced research librarian.However, it is essential to acknowledge the limitations inherent in a scoping review, which include a restricted number of databases and potential biases during the screening and selection of studies.This scoping review is also limited as it assesses the frameworks and tools within the included studies exclusively based on their incorporation of health, environmental, and economic benefits associated with trees and greenspace.While we gathered information on other critical criteria, such as the tools' development process (e.g., the depth of evidence and the participatory nature of the approaches employed), adaptability to evolving evidence, accessibility, and digital format availability, we did not employ these criteria for scoring and ranking the frameworks and tools.Despite these limitations, our study offers an extensive overview of the current decision-making landscape, shedding light on the significant gaps within the existing frameworks and tools in terms of their comprehensiveness in addressing the health, environmental, and economic benefits of trees and greenspace.

Conclusions
In conclusion, our scoping review has shed light on the state of urban planning decision-making processes concerning the integration of health, environmental, and economic benefits associated with trees and greenspace.The findings underscore a significant gap in current practices, as none of the studies examined reported processes that adequately and comprehensively incorporated all three dimensions of these benefits.It is therefore no surprise that preserving trees or increasing the quality and quantity of greenspace, more often than not, become the second or third priority in any new or existing development as there is no framework, model, or tool that can comprehensively assist decision makers.
This review highlights a pressing need for the development and adoption of more comprehensive urban planning decision-making processes that fully integrate health, environmental, and economic benefits associated with trees and greenspace.To move forward, urban planners, policy makers, and researchers should work together to bridge these gaps by creating and implementing frameworks and tools that take into account the multifaceted benefits of urban trees and greenspace.Importantly, future research in this area should focus to address the critical gap in terms of incorporating the true economic and monetary values of health and environmental benefits of trees and greenspace, which is crucial for informed and holistic urban development decision making.

Green Space (s) Decision-Making Processes Urban Planning
Green Table A3.Scopus Logic Grid.

Greenspace Decision-Making Processes Urban Planning
TITLE-ABS-KEY("Green space*" OR Trees OR "Green belt*" OR Parkland* OR "Urban Green*" OR Greenif* OR Greenspace OR "Green Infrastructure" OR Green-space) TITLE-ABS-KEY("Decision mak*" OR "Decision procedure*" OR "Decision logic" OR "Decision matrix" OR "Decision tool*" OR "Decision framework*" OR Planning tool*" OR "Planning framework*) TITLE-ABS-KEY("Urban planning" OR "Town planning" OR "City planning" OR "Urban development" OR "Environmental design" OR "Local plan*") Table A4.Public Health Database Logic Grid.

Greenspace Decision-Making Processes Urban Planning
"Green space*" OR Trees OR "Green belt*" OR Parkland* OR "Urban Green*" OR Greenif* OR Greenspace OR "Green Infrastructure OR Green-space" "Decision mak*" OR "Decision procedure*" OR "Decision logic" OR "Decision matrix" OR "Decision tool*" OR "Decision framework*" OR "Planning tool*" OR "Planning framework*" "Urban planning" OR "Town planning" OR "City planning" OR "Urban development" OR "Environmental design" OR "Local plan*" Table A5.Web of Science Logic Grid.

Greenspace Decision-Making Processes Urban Planning
"Green space*" OR Trees OR "Green belt*" OR Parkland* OR "Urban Green*" OR Greenif* OR Greenspace OR "Green Infrastructure OR Green-space" "Decision mak*" OR "Decision procedure*" OR "Decision logic" OR "Decision matrix" OR "Decision tool*" OR "Decision framework*" OR "Planning tool*" OR "Planning framework*" "Urban planning" OR "Town planning" OR "City planning" OR "Urban development" OR "Environmental design" OR "Local plan*" Table A6.Google Advanced Search Logic Grid.

Greenspace Decision-Making Processes Urban Planning
("Green space*" OR Trees OR "Green belt*" OR Parkland* OR "Urban Green*" OR Greenif* OR Greenspace OR "Green Infrastructure") ("Decision procedure*" OR "Decision logic" OR "Decision matrix" OR "Decision mak*") ("Urban plan*" OR "Town plan*" OR "City plan*" OR "Urban development" OR "Environmental design" OR "Local plan*") Does not quantify costs/benefits of health implications of ecosystem services.The complexity of ecosystem services had to be simplified for the purposes of the framework, meaning some of the nuance was lost.

Appendix B. Summary Results of Publications Included in the Scoping Review
[50] 2016 The Netherlands Sustainability and resilience benefits assessment (SRBA) identifies the sustainability benefits associated with a development.A systems-thinking approach was used to develop a matrix which demonstrates the type of sustainability and resilience benefits which can be expected from a project.

Yes Yes Yes
Integrates top-down and bottom-up approaches.Cities able to decide which sustainability indicators are most relevant to them.
Assesses growth, revenue, and balance of payment but does not quantify the health and environmental costs/benefits.Authors recognize that increasing sustainability in one area may inevitably decrease it in another, meaning that the tool does have some tradeoffs.
[51] 2021 Australia The System of Experimental Ecosystem Accounting (SEEA) framework assigns monetary values to environmental assets in order to determine their worth.Estimates of monetary value were generated using i-tree, a literature review, and a series of nonmarket valuation estimations and benefit transfer estimations.

No Yes Yes
Tool interprets the "cost" of a natural asset in two ways; the physical value of the asset and the value of the ecosystem services it provides; thus quantifies the costs/benefits of environmental impacts of greenspace.Article highlights where further research/data are required.
Human health implications of greenspace are not considered.Some benefits were not able to be measured due to inadequate data.

Yes Yes No
Open access and user-friendly.Developed tool after comparative analysis of the strengths and limitations of similar tools.
Economic implications of greenspace are not considered.Chose not to include air quality as a function.
[53] 2018 Malysia The WIND tool uses a comprehensive list of variables to evaluate an area's walkability based on its environmental and physical attributes.The "most in use" philosophical approach was used to create the tool along with mind-mapping and decision-tree methods to collect primary data from pedestrians.

Yes No No
Provides scored index to benchmark the walkability of each urban neighborhood, assisting urban planners in prioritization.
Environmental and economic factors not considered.Potential for biodiverse greenspace in walkable areas has been missed-study only focuses on walkability.
[54] 2018 USA A framework which guides urban planners to make decisions which will improve community health.The framework presents a "current state" and a "desired state" and suggests a tool kit which can take a community from its current state to its desired state.These tools include a health impact assessment, public health tracking, EPA EnviroAtlas and C-FERST, and cumulative risk assessment.

Yes No No
Framework shows a clear path from "current state" to "desired state" and includes steps on how to achieve this.
Economic burden of environment-related disease is acknowledged yet not included in the framework.Environmental factors not considered.The tool classifies streets based on their UHI from low to high and provides guidance on where additional vegetation would assist in lowering UHI.A data-driven modeling approach was used to develop the tool.

No Yes No
Publicly available data can be used to operate the decision matrix and categorize streets based on their UHI impact.The five levels of classification are straightforward and easy to interpret.
Health and economic implications of greenspace are not considered.Had air temperature been used to determine UHI rather than SUHI, the results may have been different-this should be investigated in future research.[62] 2015 Poland Hellwig's method was applied to create a mathematical algorithm tool which identifies the ecological significance of urban greenspace and their groupings.Data were derived from the literature as well as primary data collected specifically for the study.

No Yes No
Would improve transparency in urban planning, could potentially be used to mitigate conflict in planning, provides the opportunity for standardized rankings to definitively and transparently present options.
Health and economic implications of greenspace are not considered.Hellwig's method treats multiple similar greenspaces as redundant and would therefore advise to remove them as they do not add different biodiversity, even though they add more biodiversity.The method also does not account for areas acting as ecological corridors or connectivity between greenspace networks.Particular cases therefore require further evaluation by urban ecologists.

Yes
Yes Yes Acknowledges that human and ecosystem health are inextricably linked, as well as considering the cost effectiveness of green infrastructure.
Focuses on cost effectiveness but acknowledges that there are economic benefits to the environment and human health.Cost effectiveness of removing invasive species requires more information as it is currently based on assumptions.Economic implications of greenspace are not considered.[68] 2018 Romania WebGIS mapping portal for urban climate determines the impact of UHI on human health and comfort.
To achieve this, remote sensing, geographical information systems, crowdsourcing, and microclimatic modeling were utilized.

Yes Yes No
Is accessible enough to be used by the public as well as urban planners.Transparent.
Economic implications of greenspace are not considered.E-participation is encouraged, which can be a good way of engaging the public but can also invite unhelpful or irrelevant information.The GIUR-PSS framework assesses scenarios for their environmental, social, economic, and cultural dimensions of resilience.This tool not only assesses these three aspects of green infrastructure but combines qualitative and quantitative indicators using the fuzzy comprehensive evaluation (FCE) method.The assessment process is embedded in a planning support system (PSS) which combines geospatial data, methods, and technologies to assist with decision making in planning.
Literature-based scenario generation and indicator set was coupled with either expert surveys or modeling using primary and secondary data.

Yes Yes Yes
Multidimensional approach assesses for social, economic, environmental, and cultural dimensions of resilience.Can also incorporate both qualitative and quantitative factors in a scenario assessment.
Acknowledges the financial costs/benefits of greenspace (e.g., maintenance) but does not quantify the health and environmental costs/benefits.Scenarios can only assess one type of green infrastructure in one study area-they cannot assess one study area with multiple types of green infrastructure.
[70] 2013 Serbia The analytic hierarchy process (AHP) model was used in conjunction with a group decision-making framework and the consensus convergence model (CCM) in order to make decisions with regard to urban planning.Preexisting framework was customized and then tested by a team of experts.

Yes Yes
No Easy-to-understand and -operate approach.
Economic implications of greenspace are not considered.Requires all decision makers in the group to reach a consensus.

Figure 1 .
Figure 1.Conceptual framework used to evaluate included decision-making frameworks/models/tools.

Figure 1 .
Figure 1.Conceptual framework used to evaluate included decision-making frameworks/models/tools.

Figure 3 .
Figure 3.The temporal trend of publications discussing health, environmental, and economic benefits of trees and greenspace within the urban planning context.

Table 1 .
Comprehensiveness of the reviewed frameworks/models/tools in terms of incorporating trees and greenspace benefits.

Table A7 .
Extracted Descriptive Data for Evaluated Frameworks, Models, and Tools in the Scoping Review.