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Will Biodiversity Actions Yield Healthy Places? A Systematic Review of Human Health Outcomes Associated With Biodiversity-Focused Urban Greening
Figure 1. Seven biodiversity-supporting elements in urban landscapes and definitions for each. Biodiversity-supporting elements are adapted from Spotswood et al. (2019). There is growing interest in using urban greening projects to support biodiversity. While there are many potential co-benefits, the health outcomes resulting from biodiversity-supporting activities have yet to be synthesized. We conducted a systematic review of health outcomes associated with seven biodiversity-supporting elements, including patch size, connections, matrix quality, habitat diversity, native plants, special resources and vegetation management. We identified 1550 studies linking elements with human health. Results show that many types of biodiversity-supporting elements are associated with a wide range of positive health outcomes. These outcomes included improved physical and mental health, increased physical activity, improved childhood development, social outcomes, and reduced exposure to harms such as sun, heat, and pollution (including light, air and noise). Other biodiversity-supporting elements such as reducing pesticide use, native plants, and habitat diversity were associated with a smaller and more specific range of health outcomes. While most findings showed positive associations between biodiversity-supporting elements and health, many also yielded mixed, neutral, or negative findings. Further, most identified study designs were observational, limiting our ability to uncover causality. We found that studies using a natural experimental design yielded a greater fraction of mixed, neutral, and negative findings compared to observational designs (the majority of studies) and experimental studies (largely short term in nature). These results confirm concerns about the strength of research findings built largely on correlational research designs. We also identify areas of trade-off between biodiversity-supporting elements and human health. These include actions that positively affect health yet negatively impact biodiversity, such as the maintenance of sports fields and trails in parks that can negatively impact habitat and disrupt wildlife behaviour. Biodiversity-supporting elements can also negatively impact some dimensions of human health, including by increasing human–wildlife conflict, disease vectors, allergenic pollen, biogenic volatile organic compounds (BVOCs), through and green gentrification. Our review reveals a large potential for co-benefits for human health to come from biodiversity-focused actions in cities. Careful attention to minimizing tensions and trade-offs could help to reduce the potential for conflict between biodiversity and human health objectives.
Read moreMeasuring Urban Nature for Pedestrian Health: Systematic Review and Expert Survey
Walking and access to nature are two of the most effective health promotion and disease prevention strategies. There has been a growing interest in the dynamic pathways among access to nature, walking, and health. Effective measurement of these variables is the prerequisite to advancing our understanding of such pathways. However, contrasting to the rigorous methods available for walking and health measures, methods to quantify nature have been limited. This study uses a systematic literature review to synthesize urban nature measures (UNMs) used in published studies linking urban nature with pedestrian health outcomes (e.g. walking, physical activity, physical health, mental health). A survey of experts (n = 30) was used to identify additional and emerging methods. The literature search identified 115 articles and 48 UNMs most of which (40 or 83%) were objective measures. Results showed no consensus on the optimal UNMs for pedestrian health research, but certain measures such as NDVI, proximity to green spaces, and area/proportion of green spaces, were popularly used in previous studies. Experts suggested emerging methods including LiDAR, GPS, high-resolution imagery, virtual/augmented reality, and context-sensitive ecological momentary assessment. Major gaps in current UNMs included the shortage of eye-level and quality-related measures. While experts acknowledge the promise of emerging technologies, they shared concerns related to privacy, digital divide, confidentiality, and bias. This study offers insights into the UNMs available to quantify nature for pedestrian health research, which can serve to facilitate future research, community actions, and policy changes aimed at promoting walking and nature access for healthier urban communities.
Read moreUnsheltered Homelessness in Public Natural Areas Across an Urban-to-Wildland System: Institutional Perspectives
Figure 1. Conceptual relationships and interactions among social and ecological subsystems related to unsheltered homelessness in public natural areas. This article conceptualizes homelessness on public lands within a social-ecological systems framework, exploring dynamics in public natural areas in the Seattle metropolitan area (USA), a system with a compact urban-to-wildland gradient. While prior research has studied the dynamics of unsheltered homelessness within particular parks or cities—often in areas where camping is prohibited—our interview-based study makes integrated considerations of these dynamics across a range of jurisdictions. We present a thematic analysis that examines professionally diverse perspectives on the dynamics, stressors, and outcomes of public natural area usage by unsheltered individuals. We found a generally uncoordinated system in continual motion, in which considerable resources were expended for short-term, site-specific solutions that yielded system-wide detrimental outcomes perceived for unsheltered individuals, social service and environmental institutions, and ecosystem health. We discuss how improved institutional coordination and mutual understanding about intersecting governance systems could sustain better public land, public health, and social outcomes.
Read moreInequitable Changes to Time Spent in Urban Nature During COVID-19: A Case Study of Seattle, WA with Asian, Black, Latino, and White Residents
Figure 1. Change to average frequency of urban nature interaction among each racial/ethnic group The COVID-19 pandemic has impacted everyone in urban areas. Some of these impacts in the United States have negatively affected People of Color more than their White counterparts. Using Seattle, Washington as a case study, we investigated whether inequitable effects appear in residents’ interactions with urban nature (such as urban green space). Using a 48-question instrument, 300 residents were surveyed, equally divided across four racial/ethnic groups: Asian, Black and African American, Latino/a/x, and White. Results showed that during the span of about 6 months after the onset of the pandemic, Black and Latino residents experienced a significant loss of time in urban nature, while Asian and White residents did not. The implications of these findings, including inequities in the potential buffering effects of urban nature against COVID-19 and the future of urban nature conservation, are discussed. Multiple variables were tested for association with the changes to time spent in urban nature, including themes of exclusion from urban nature spaces found throughout the existing literature. Findings show that decreases in time spent in urban nature among Black and Latino residents may be associated with their feeling as though they did not belong in urban nature. We provide recommendations based on these findings for how government agencies can promote more equitable access to urban nature during the pandemic and beyond. The results of this study have implications that extend beyond the US and are relevant to the international scholarly literature of inequities and urban nature interaction during the COVID-19 pandemic.
Read moreClimate Adaptation Actions for Urban Forests and Human Health
Urban areas can be particularly vulnerable to climate change due to extensive impervious cover, increased pollution, greater human population densities, and a concentration of built structures that intensify impacts from urban heat, drought, and extreme weather. Urban residents are at risk from a variety of climate stressors, which can cause both physical and mental harm. Urban forests and tree cover provide a critical role in helping cities address climate change by supporting greenhouse gas mitigation, reducing the impacts of extreme heat and altered climate that impair human health, and helping communities to adaptively respond through engagement with nature. At the same time, urban forests are vulnerable to changes in climate and in need of robust strategies to adapt to those changes. As climate change impacts increase, efforts to “green” cities and adapt urban forests to changing conditions take on greater importance to support human health and well-being. Urban forest managers and allied professionals are looking for information to reduce climate risks to urban forests and secure their benefits for people and ecosystems. This report, Climate Adaptation Actions for Urban Forests and Human Health, synthesizes adaptation actions to address climate change in urban forest management and promote human health and well-being through nature-based solutions. It compiles and organizes information from a wide range of peer-reviewed research and evidence-based reports on climate change adaptation, urban forest management, carbon sequestration and storage, and human health response to urban nature. This report includes the Urban Forest Climate and Health Adaptation Menu, which presents information and ideas for optimizing the climate and human health outcomes of urban forestry projects and provides professionals who are working at the intersection of climate, public health, and urban forestry with resources to support climate adaptation planning and activities. Notably, it does not provide specific recommendations or guidance for any particular place; rather, it offers a range of action opportunities at different scales that can be incorporated into either comprehensive or specific climate adaptation initiatives. The Menu can be used with an existing, tested adaptation process to help managers consider climate risks and explore the benefits and drawbacks of potential adaptation actions within the context of a particular situation or project. It also can be useful for generating productive discussions about community needs and values to guide planning, education and outreach, research, or changes in policy or infrastructure within communities.
Read moreRelatively Wild Urban Parks can Promote Human Resilience and Flourishing: A Case Study of Discovery Park, Seattle, Washington
Human interaction with nature is vital for physical health and mental well-being, and positions a community to be resilient to urban stressors. Yet urban development continues to put pressures on natural areas within urban boundaries. As a case in point, Seattle’s largest park, Discovery Park, of over 500 acres, is often under threat of some form of development. The central question of this study was whether the benefits to visitors of Discovery Park depend, in no small measure, on the park’s very size and relative wild landscape. Toward addressing this question, 320 participants provided written narratives (through our web portal) about the meaningful ways in which they interacted with nature at Discovery Park. Each individual narrative was then analyzed and coded using an Interaction Pattern (IP) approach, which provides characterizations of human-nature interaction that have ontogenetic and phylogenetic significance. Results revealed 520 Interaction Patterns (IPs). The most frequently occurring IPs clustered under the keystone IPs of Encountering Wildlife (27%), Following Trails (14%), Walking to Destination Spots in Nature (8%), Gazing out at the Puget Sound or Mountains (6%), Walking Along Edges of Beach or Bluffs (5%), and Walking with Dogs (4%). Results also revealed that visitors’ meaningful interactions with nature in Discovery Park depended on the park’s relative wildness. For example, (a) 77% of participants’ IPs depended on Discovery Park’s relative wildness; (b) of the participants who specified an especially meaningful experience with nature, 95% of them had an interaction that depended on Discovery Park’s relative wildness; and (c) of the participants whose IPs were linked to other aspects of the nature in the park or to their own positive mental states, 95 and 96%, respectively, had an interaction that depended on Discovery Park’s relative wildness. Discussion focuses on how human interaction with large and relatively wild urban parks helps reverse the trend of environmental generational amnesia, and a domination worldview, and thus should be prioritized in urban planning.
Read moreCoding Manual for “The Nature Voices of People Who Visit Discovery Park: An Interaction Pattern Approach”
Chris TarnawskiDiscovery Park Lighthouse. Credit: Chris Tarnawski. Interaction with nature is vital for human physical health and mental well-being, yet urban development continues to put pressures on natural areas that allow for essential forms of human-nature interaction. Discovery Park, the largest park within Seattle—with over 500 acres and almost 12 miles of walking trails—is a case in point insofar as some Seattle constituents would like to develop some of its open space. The goal of this research is to give voice to how visitors of Discovery Park interact with nature at the park. To accomplish this, we applied an Interaction Pattern Approach, where “interaction patterns” are defined as fundamental ways of interacting with nature that are characterized abstractly enough such that many different instantiations of each pattern can be engendered. After their visit to Discovery Park, participants were asked to access our website (what we called “the Nature Language Website”) to write a few sentences or paragraphs that described a meaningful experience they had interacting with nature in the park. Participants were also asked a few demographic questions. This technical report provides our coding manual—our systematic method to code the qualitative data—of people who visited Discovery Park, and who wrote of how they interacted with nature in the park. This technical report thereby provides open access to our core intellectual qualitative work on this project. It can be used by others to conduct related research on how people interact with nature, and especially natural landscapes.
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Social-Ecological and Technological Factors Moderate the Value of Urban Nature
Figure 1. Actions lead to changes in the value of urban ecosystem services, defined by a change in human well-being, which may be different for different groups of people, hence the importance of considering equity. The relationships between actions and value are moderated by social, ecological or technological factors. For each action that leads to a change in value, there may also be co-benefits (for example, positive impacts on other sustainability goals) and disservices (for example, unintended negative consequences). Finally, decision-makers require the ability to compare the net value of urban ecosystem services relative to substitutes or alternative interventions designed to meet the same goals. Urban nature has the potential to improve air and water quality, mitigate flooding, enhance physical and mental health, and promote social and cultural well-being. However, the value of urban ecosystem services remains highly uncertain, especially across the diverse social, ecological and technological contexts represented in cities around the world. We review and synthesize research on the contextual factors that moderate the value and equitable distribution of ten of the most commonly cited urban ecosystem services. Our work helps to identify strategies to more efficiently, effectively and equitably implement nature-based solutions.
Read moreAre California Elementary School Test Scores More Strongly Associated With Urban Trees Than Poverty?
Figure 1. Model selection results for several common variables for student test performance on a sample of California fifth grade classes. Effect sizes (A) were significant for urban/rural location, % minority representation and % student body on free and reduced lunches. Minority representation (B) showed the strongest signal, with a two SD difference in minorities associated with a 100 point difference in overall test scores. Unprecedented rates of urbanization are changing our understanding of the ways in which children build connections to the natural world, including the importance of educational settings in affecting this relationship. In addition to influencing human-nature connection, greenspace around school grounds has been associated with benefits to students’ cognitive function. Questions remain regarding the size of this benefit relative to other factors, and which features of greenspace are responsible for these effects. We conducted a large-scale correlative study subsampling elementary schools (n = 495) in ecologically, socially and economically diverse California. After controlling for common educational determinants (e.g., socio-economic status, race/ethnicity, student teacher ratio, and gender ratio) we found a significant, positive association between test scores and tree and shrub cover within 750 and 1000 m of urban schools. Tree and shrub cover was not associated with test scores in rural schools or five buffers closer to urban schools (10, 50, 100, 300, and 500 m). Two other greenspace variables (NDVI and agricultural area) were not associated with test performance at any of the analyzed buffer distances for rural or urban schools. Minority representation had the largest effect size on standardized test scores (8.1% difference in scores with 2SD difference in variable), followed by tree and shrub cover around urban schools, which had a large effect size (2.9–3.0% at 750 and 1000 m) with variance from minority representation and socioeconomic status (effect size 2.4%) included. Within our urban sample, average tree-cover schools performed 4.2% (3.9–4.4, and 95% CI) better in terms of standardized test scores than low tree-cover urban schools. Our findings support the conclusion that neighborhood-scale (750–1000 m) urban tree and shrub cover is associated with school performance, and indicate that this element of greenspace may be an important factor to consider when studying the cognitive impacts of the learning environment. These results support the design of experimental tests of tree planting interventions for educational benefits.
Read moreGeolocated Social Media as a Rapid Indicator of Park Visitation and Equitable Park Access
Figure 1. Alignment of Census block group, park and park buffer boundaries. The block group boundary in which Central Park is contained includes residential areas bordering the park. When population density within the 400m buffer is averaged over Census block groups, density of the residential areas bordering the park are underestimated due to the inclusion of the park’s area. Understanding why some parks are used more regularly or intensely than others can inform ways in which urban parkland is developed and managed to meet the needs of a rapidly expanding urban population. Although geolocated social media (GSM) indicators have been used to examine park visitation rates, studies applying this approach are generally limited to flagship parks, national parks, or a small subset of urban parks. Here, we use geolocated Flickr and Twitter data to explore variation in use across New York City’s 2143 diverse parks and model visitation based on spatially-explicit park characteristics and facilities, neighborhood-level accessibility features and neighborhood-level demographics. Findings indicate that social media activity in parks is positively correlated with proximity to public transportation and bike routes, as well as particular park characteristics such as water bodies, athletic facilities, and impervious surfaces, but negatively associated with green space and increased proportion of minority ethnicity and minority race in neighborhoods in which parks are located. Contrary to previous studies which describe park visitation as a form of nature-based recreation, our findings indicate that the kinds of green spaces present in many parks may not motivate visitation. From a social equity perspective, our findings may imply that parks in high-minority neighborhoods are not as accessible, do not accommodate as many visitors, and/or are of lower quality than those in low-minority neighborhoods. These implications are consistent with previous studies showing that minority populations disproportionately experience barriers to park access. In applying GSM data to questions of park access, we demonstrate a rapid, big data approach for providing information crucial for park management in a way that is less resource-intensive than field surveys.
Read moreTechnological Nature and Human Well-Being
In terms of physical and psychological well-being, does it matter that on a worldwide level we are replacing interactions with actual nature with technological nature—technologies that mediate, simulate, and augment the natural word? Research from three forms of technological nature are reviewed: a technological nature window, robot pets, and a telegarden. Results suggest that while interacting with technological nature is better than nothing, it is not as good as interacting with real nature. A concern with accepting technological nature is that it can shift the baseline downward for what counts as optimal well-being, as people across generations lose experiences with healthy baselines, a process referred to as environmental generational amnesia. One result is that we ask too little of the idea of urban sustainability, confusing biological living with human flourishing.
Read moreUsing Social Media to Understand Drivers of Urban Park Visitation in the Twin Cities, MN
Figure 1. Distribution of urban park and green space polygons in the Twin Cities Metropolitan Area, MN, USA. Green space and parks in urban environments provide a range of ecosystem services and public benefits. However, planners and park managers can lack tools and resources to gather local information on how parks are used and what makes them desirable places for recreation and a wide variety of uses. Traditional survey methods to monitor park use and user preferences can be costly, time consuming, and challenging to apply at scale. Here, we overcome this limitation by using geotagged social media data to assess patterns of visitation to urban and peri-urban green space across park systems in the metropolitan area of the Twin Cities, Minnesota, USA. We find that parks with nearby water features, more amenities, greater accessibility from the presence of trails, and that are located within neighborhoods with higher population density, are associated with higher rates of visitation. As cities grow and shifts in demographics occur, more responsive management of public green space will become increasingly important to ensure urban parks provide ecosystem services and meet users’ needs. Using social media data to rapidly assess park use at a lower cost than traditional surveys has the potential to inform public green space management with targeted information on user behavior and values of urban residents.
Read morePhotos, Tweets, and Trails: Are Social Media Proxies for Urban Trail Use?
Figure 1: Maps of annual average daily trail traffic (AADTT), annual average photo-user days (AAPUD), and annual averageTwitter-user days (AATUD) Decision makers need information on the use of, and demand for, public recreation and transportation facilities. Innovations in monitoring technologies and diffusion of social media enable new approaches to estimation of demand. We assess the feasibility of using geo-tagged photographs uploaded to the image-sharing website Flickr and tweets from Twitter as proxy measures for urban trail use. We summarize geo-tagged Flickr uploads and tweets along 80 one-mile segments of the multiuse trail network in Minneapolis, Minnesota, and correlate results with previously published estimates of annual average daily trail traffic derived from infrared trail monitors. Although heat maps of Flickr images and tweets show some similarities with maps of variation in trail traffic, the correlation between photographs and trail traffic is moderately weak (0.43), and there is no meaningful statistical correlation between tweets and trail traffic. Use of a simple log-log bivariate regression to estimate trail traffic from photographs results in relatively high error. The predictor variables included in published demand models for the same trails explain roughly the same amount of variation in photo-derived use, but some of the neighborhood socio-demographic and built-environment independent variables have different effects. Taken together, these findings show that both Flickr images and tweets have limitations as proxies for demand for urban trails, and that neither can be used to develop valid, reliable estimates of trail use. These results differ from previously published results that indicate social media may be useful in assessing relative demand for recreational destinations. This difference may be because urban trails are used for multiple purposes, including routine commuting and shopping, and that trail users are less inclined to use social media on trips for these purposes.
Read moreLiving in Cities, Naturally
Figure 1. Together with ecological benefits such as climate change mitigation and the protection of biological diversity, the renaturing of cities opens opportunities for people to engage with features and processes of the natural world; for example, when tending plants in a community garden. Natural features, settings, and processes in urban areas can help to reduce stress associated with urban life. In this and other ways, public health benefits from, street trees, green roofs, community gardens, parks and open spaces, and extensive connective pathways for walking and biking. Such urban design provisions can also yield ecological benefits, not only directly but also through the role they play in shaping attitudes toward the environment and environmental protection. Knowledge of the psychological benefits of nature experience supports efforts to better integrate nature into the architecture, infrastructure, and public spaces of urban areas.
Read moreNature Experience Reduces Rumination and Subgenual Prefrontal Cortex Activation
Figure 1. The impact of nature experience on self-reported rumination and blood perfusion to the sgPFC. (A) Change in self-reported rumination (postwalk minus prewalk) for participants randomly assigned to take a 90-min walk either in a natural setting or in an urban setting. (B) A time-by-environment interaction in blood perfusion was evident in the sgPFC. F map of significant interactions at a threshold of P < 0.05, FWE corrected for multiple comparisons. (C) Change in blood perfusion (postwalk minus prewalk) for participants randomly assigned to take a 90-min walk either in a natural setting or in an urban setting. Error bars represent SE within subjects: *P < 0.05, ***P < 0.001. Significance More than 50% of people now live in urban areas. By 2050 this proportion will be 70%. Urbanization is associated with increased levels of mental illness, but it’s not yet clear why. Through a controlled experiment, we investigated whether nature experience would influence rumination (repetitive thought focused on negative aspects of the self), a known risk factor for mental illness. Participants who went on a 90-min walk through a natural environment reported lower levels of rumination and showed reduced neural activity in an area of the brain linked to risk for mental illness compared with those who walked through an urban environment. These results suggest that accessible natural areas may be vital for mental health in our rapidly urbanizing world. Abstract Urbanization has many benefits, but it also is associated with increased levels of mental illness, including depression. It has been suggested that decreased nature experience may help to explain the link between urbanization and mental illness. This suggestion is supported by a growing body of correlational and experimental evidence, which raises a further question: what mechanism(s) link decreased nature experience to the development of mental illness? One such mechanism might be the impact of nature exposure on rumination, a maladaptive pattern of self-referential thought that is associated with heightened risk for depression and other mental illnesses. We show in healthy participants that a brief nature experience, a 90-min walk in a natural setting, decreases both self-reported rumination and neural activity in the subgenual prefrontal cortex (sgPFC), whereas a 90-min walk in an urban setting has no such effects on self-reported rumination or neural activity. In other studies, the sgPFC has been associated with a self-focused behavioral withdrawal linked to rumination in both depressed and healthy individuals. This study reveals a pathway by which nature experience may improve mental well-being and suggests that accessible natural areas within urban contexts may be a critical resource for mental health in our rapidly urbanizing world. Related Media Nature May Be Key to Strengthening Our Attention (November 28, 2023) Stanford researchers find mental health prescription: Nature (June 30, 2015)
Read moreDesigning for Human Values in an Urban Simulation System: Value Sensitive Design and Participatory Design
UrbanSim is a large-scale simulation system that models the development of urban areas over periods of 20 or more years. Its purpose is to help citizens and local governments make more informed decisions about major transportation and land use issues, by projecting the long-term consequences of the different alternatives. Citizens often bring strongly held values to such decisions, for example regarding equity, sustainability, environmental protection, economic expansion, or property rights, and the decisions are often politically charged. To help shape the design of UrbanSim to better support the democratic process, as well as to be responsive to the values held by different stakeholders and the conflicts among them, we are using Value Sensitive Design, a theoretically grounded approach to the design of technology that seeks to account for human values in a principled and comprehensive manner throughout the design process. Participatory Design also has a good deal to say about these issues. Thus, in this paper, we first describe UrbanSim and Value Sensitive Design, and provide a snapshot of our ongoing work in this area. We then use the UrbanSim work as an example to bring out key commonalities and differences between Value Sensitive Design and Participatory Design, and to motivate some preliminary ideas about ways in which each methodology could evolve based on techniques and concepts from the other.
Read moreEnvironmental Views and Values of Children in an Inner‐City Black Community
72 children across grades 1, 3, and 5 (mean ages, 7–5, 9–6, and 11–4) from an economically impoverished inner-city Black community were interviewed on their views and values about the natural environment. Assessments were made on whether children were aware of environmental problems, discussed environmental issues with their family, valued aspects of nature, and acted to help the environment. Additional assessments pertained to the prescriptivity and generalizability, and supporting justifications, of children’s normative environmental judgments based on a hypothetical scenario that involved polluting a waterway. Overall, children showed sensitivity to nature and awareness of environmental problems, although attenuated by both developmental and cultural factors. Most children believed that polluting a waterway was a violation of a moral obligation. Children’s environmental moral reasoning largely focused on homocentric considerations (e.g., that nature ought to be protected in order to protect human welfare). With much less frequency, children focused on biocentric considerations (e.g., that nature has intrinsic value or rights). Findings are discussed in terms of moral-developmental theory, and the place of social-cognitive research in understanding the human relationship to the natural environment.
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