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Nature and Health: Perspectives and Pathways
As many scholars have noted, research and publications on the benefits of nature experience have grown substantially over recent years. Progress has been made on empirical fronts based on perspectives from psychology, epidemiology, sociology, exposure science, urban design, and other disciplines. Studies have revealed ways in which health outcomes differ by population characteristics (e.g., socioeconomic status), individual differences (e.g., states of baseline mental health), and interactions with different types of nature (e.g., street trees vs. large parks vs. deserts) (Barnes et al., 2019; Mitchell & Popham, 2008; Mitchell, Richardson, & Shortt, 2015; Olvera-Alvarez, Browning, Neophytou, & Bratman, 2021; Tester-Jones et al., 2020; Wheeler et al., 2015; Yin, Bratman, Browning, Spengler, & Olvera-Alvarez, 2022). Together, the evidence also illustrates the importance of accounting for different ways of “operationalizing nature” (e.g., Normalized Difference Vegetation Index [NDVI]), and methods of measuring exposure (e.g., subjective vs. objective), as well as the granularity in assessments of frequency and duration (Ekkel & de Vries, 2017; Shanahan et al., 2016).
Read moreStress Recovery from Virtual Exposure to a Brown (Desert) Environment Versus a Green Environment
Fig. 1. Experimental procedure. Note: Mean arterial pressure, pulse, and cortisol measures were collected 6 times during the experiment (i.e. Stage T0∼T5). Serum samples were collected at T0 and T5. TSST: Trier Social Stressor Test. The beneficial association between nature contact and human health is often explained with psycho-evolutionary frameworks such as stress reduction theory and the savanna hypothesis. However, evidence is limited on how natural environments that are not green affect stress. One example is the desert, which does not offer affordances for nourishment or safety in an evolutionary sense. In this study, we determine the effect of a virtual reality (VR) exposure to a desert vs. green environment among 95 healthy adult male residents of El Paso, Texas. The procedure consisted of an acute stressor followed by random assignment to a 10 min VR experience (desert, green space, or office [control condition]) and a 40 min resting period. Participants in the desert condition showed significant reductions in salivary cortisol compared to participants in the office. Participants in the desert condition showed decreases in mean arterial pressure compared to participants in the control condition. Collectively, these findings suggest that factors beyond those proposed by psycho-evolutionary frameworks such as lived experiences and familiarity with landscapes may play a role in the health benefits of nature exposure.
Read moreWhat Can We Do When the Smoke Rolls In? An Exploratory Qualitative Analysis of the Impacts of Rural Wildfire Smoke on Mental Health and Well-Being, and Opportunities for Adaptation
Figure 1. Suggested content, distribution location, medium, and messenger for a wildfire smoke and wellbeing toolkit Background Extreme, prolonged wildfire smoke (WFS) events are becoming increasingly frequent phenomena across the Western United States. Rural communities, dependent on contributions of nature to people’s quality of life, are particularly hard hit. While prior research has explored the physical health impacts of WFS exposure, little work has been done to assess WFS impacts on mental health and wellbeing, or potential adaptation solutions. Methods Using qualitative methods, we explore the mental health and wellbeing impacts experienced by community members in a rural Washington State community that has been particularly hard hit by WFS in recent years, as well as individual, family, and community adaptation solutions. We conducted focus groups with residents and key informant interviews with local health and social service providers. Results Participants identified a variety of negative mental health and wellbeing impacts of WFS events, including heightened anxiety, depression, isolation, and a lack of motivation, as well as physical health impacts (e.g., respiratory issues and lack of exercise). Both positive and negative economic and social impacts, as well as temporary or permanent relocation impacts, were also described. The impacts were not equitably distributed; differential experiences based on income level, outdoor occupations, age (child or elderly), preexisting health conditions, housing status, and social isolation were described as making some residents more vulnerable to WFS-induced physical and mental health and wellbeing challenges than others. Proposed solutions included stress reduction (e.g., meditation and relaxation lessons), increased distribution of air filters, development of community clean air spaces, enhancing community response capacity, hosting social gatherings, increasing education, expanding and coordination risk communications, and identifying opportunities for volunteering. Findings were incorporated into a pamphlet for community distribution. We present a template version herein for adaptation and use in other communities. Conclusions Wildfire smoke events present significant mental health and wellbeing impacts for rural communities. Community-led solutions that promote stress reduction, physical protection, and community cohesion have the opportunity to bolster resilience amid this growing public health crisis.
Read moreAffective Benefits of Nature Contact
Figure 1. Nature contact and the process model of emotion regulation. We describe the ways in which these five family of strategies may be influenced by natural environmental factors, which in turn leads to affective benefits. Figure icon made by eucalyp from www.flaticon.com Mounting evidence demonstrates that nature exposure can have affective benefits. These include behavioral and psychophysiological responses consistent with (a) decreases in stress and negative affect; and (b) increases in subjective well-being and positive affect. What is less clear, however, is what mechanisms are responsible for these effects. In this article, we examine the evidence for affective impacts of nature exposure, consider underlying mechanisms (with a focus on affect regulation), and discuss what might moderate these effects at the individual and population level. We end by pointing to future research directions and practical applications. This includes investigations into the range of effects and duration of their impact, harnessing knowledge about temporal dynamics for insights into causal mechanisms, broadening the discussions around moderators and effect modifications to include diverse perspectives on the relationship between nature exposure and psychological well-being, and integrating findings into existing frameworks from public health.
Read moreAffective Benefits of Nature Contact: The Role of Rumination
Figure 1. Structural equation mediation model of the relationships between time in nature, rumination and positive and negative affect. Ovals denote latent variables (i.e., all but “Weekly time in nature”). Standardized coefficients are presented. *indicates path with significant relationship (α = 0.05). †Indicates path with marginally significant relationship (α = 0.10). For the “ab” paths, significance was tested with bootstrapped 95% confidence intervals. The “ab” paths indicate the indirect effect of time in nature on affect. The “c” paths indicate the total effect of time in nature on affect. The “c”’ paths indicate the direct effect of time in nature on affect. Mounting evidence shows that nature contact is associated with affective benefits. However, the psychological mechanisms responsible for these effects are not well understood. In this study, we examined whether more time spent in nature was associated with higher levels of positive affect in general, and lower levels of negative affect and rumination in general. We also conducted a cross-sectional mediation analysis to examine whether rumination mediated the association of nature contact with affect. Participants (N = 617) reported their average time spent in nature each week, as well as their general levels of positive and negative affect, and the degree to which they typically engaged in rumination in daily life. We then used structural equation modeling to test our hypotheses. Our results support the hypothesis that nature contact is associated with general levels of affect, and that rumination mediates this association for negative affect, and marginally mediates this association for positive affect.
Read moreAn Ecosystem Service Perspective on Urban Nature, Physical Activity, and Health
Figure 1. Conceptual model of the relationships among urban nature (as part of the urban system), PA (quantity and quality), and health, alignedwith an ecosystem service approach. Numbers correspond with The Current State of Knowledge points 1 and 2. Nature underpins human well-being in critical ways, especially in health. Nature provides pollination of nutritious crops, purification of drinking water, protection from floods, and climate security, among other well-studied health benefits. A crucial, yet challenging, research frontier is clarifying how nature promotes physical activity for its many mental and physical health benefits, particularly in densely populated cities with scarce and dwindling access to nature. Here we frame this frontier by conceptually developing a spatial decision-support tool that shows where, how, and for whom urban nature promotes physical activity, to inform urban greening efforts and broader health assessments. We synthesize what is known, present a model framework, and detail the model steps and data needs that can yield generalizable spatial models and an effective tool for assessing the urban nature–physical activity relationship. Current knowledge supports an initial model that can distinguish broad trends and enrich urban planning, spatial policy, and public health decisions. New, iterative research and application will reveal the importance of different types of urban nature, the different subpopulations who will benefit from it, and nature’s potential contribution to creating more equitable, green, livable cities with active inhabitants.
Read moreAssociations Between Green/Blue Spaces and Mental Health Across 18 Countries
Figure 1. Relationships between: (1) Green space visits in last 4 weeks, (2) Inland-blue space visits in last 4 weeks, (3) Coastal-blue space visits in last 4 weeks, and (4) nature connectedness (1–7); and positive well-being (0–100; a,e,l,m), risk of mental distress (0–1; b,f,j,n), use of depression medication (0–1; c,g,k,o), and use of anxiety medication (0–1; d,h,l,p), averaged across 18 countries (n = 16,302). Living near, recreating in, and feeling psychologically connected to, the natural world are all associated with better mental health, but many exposure-related questions remain. Using data from an 18-country survey (n = 16,307) we explored associations between multiple measures of mental health (positive well-being, mental distress, depression/anxiety medication use) and: (a) exposures (residential/recreational visits) to different natural settings (green/inland-blue/coastal-blue spaces); and (b) nature connectedness, across season and country. People who lived in greener/coastal neighbourhoods reported higher positive well-being, but this association largely disappeared when recreational visits were controlled for. Frequency of recreational visits to green, inland-blue, and coastal-blue spaces in the last 4 weeks were all positively associated with positive well-being and negatively associated with mental distress. Associations with green space visits were relatively consistent across seasons and countries but associations with blue space visits showed greater heterogeneity. Nature connectedness was also positively associated with positive well-being and negatively associated with mental distress and was, along with green space visits, associated with a lower likelihood of using medication for depression. By contrast inland-blue space visits were associated with a greater likelihood of using anxiety medication. Results highlight the benefits of multi-exposure, multi-response, multi-country studies in exploring complexity in nature-health associations.
Read moreAssociations of Residential Brownness and Greenness with Fasting Glucose in Young Healthy Adults Living in the Desert
Figure 1. Aerial image showing examples of brownness, greenness, and grayness in a residential area of El Paso, Texas, in June, 2019. Image source: GoogleEarth®, © 2020 Google; © 2020 INEGI. Evolutionary psychology theories propose that contact with green, natural environments may benefit physical health, but little comparable evidence exists for brown, natural environments, such as the desert. In this study, we examined the association between “brownness” and “greenness” with fasting glucose among young residents of El Paso, Texas. We defined brownness as the surface not covered by vegetation or impervious land within Euclidian buffers around participants’ homes. Fasting glucose along with demographic and behavioral data were obtained from the Nurse Engagement and Wellness Study (n = 517). We found that residential proximity to brownness was not associated with fasting glucose when modeled independently. In contrast, we found that residential greenness was associated with decreased levels of fasting glucose, despite the relatively low levels of greenness within the predominantly desert environment of El Paso. A difference between the top and bottom greenness exposure quartiles within a 250 m buffer was associated with a 3.5 mg/dL decrease in fasting glucose levels (95% confidence interval: −6.2, −0.8). Our results suggest that within the understudied context of the desert, green vegetation may be health promoting to a degree that is similar to other, non-desert locations in the world that have higher baselines levels of green.
Read moreNature and Children’s Health: A Systematic Review
The American Academy of Pediatrics has long recognized the importance of play and has encouraged outdoor play to promote children’s health and social-emotional development. Outdoor play environments vary widely, from urban parking lots to grass sports fields to wilderness. There is increasing evidence that outdoor play environments containing natural elements may offer health benefits that come specifically from engaging in the natural world. Recent studies have demonstrated that a broad range of outcomes are related to access to, and contact with nature, including increased physical activity, reduced obesity, decreased stress, and improved mental health. However, nature contact is not regularly experienced by all children because of urbanization, sedentary indoor lifestyles, and disparities in access to green space. Neighborhoods with more socioeconomically disadvantaged residents and families of color tend to have fewer nearby residential parks, and financial and transportation limitations that prevent access to parks and wilderness outside of city limits. This inequity extends to school grounds in low-income neighborhoods, which are less likely to have school gardens compared with schools in high-income neighborhoods. Furthermore, there is evidence that contact with nature and green space may disproportionately benefit disadvantaged populations by attenuating the toxic effects of poverty: the so-called “equigenic” effect. For these reasons, promoting nature contact and ensuring equitable access to green spaces could play a role in improving health outcomes and behaviors, and reducing health disparities. Pediatricians are uniquely positioned to offer guidance about evidence-informed interventions to promote child health during clinical interactions, and through community advocacy. Our goal was to conduct a systematic review to aggregate and evaluate the evidence regarding the effects of nature contact on children’s health, and to make it available to pediatric health care providers. Therefore, we explore the full breadth of quantitative evidence with a systematic literature search and consensus-based review process to make the evidence accessible on which to base clinical recommendations, health-promoting programs, and policies and to guide future research. Related News As Outdoor Preschools Gain Traction, States Work to Unlock Funding (January 27, 2023) Nature is Nurture: Outdoors are Key to Children’s Health, Buffer to Pandemic Stress (November 5, 2021) Children with access to nature are mentally and physically healthier (September 30, 2021) Science backs nature as key to children’s health (September 29, 2021)
Read moreNature at Work: The Effects of Day-to-Day Nature Contact on Workers’ Stress and Psychological Well-Being
Interior shot of the Spheres. Image source: AshlynG/Flickr, CC BY-ND 2.0 (G A, 2018). Objectives Chronic stress and burnout are key health issues for office workers that may contribute to a myriad of poor health outcomes. The presence of natural elements may improve psychological well-being in workers but the number of existing studies is relatively low, and more longitudinal research is specifically needed to assess how characteristics of workers’ day-to-day environments may impact mental health outcomes like affect, depression and stress. This report outlines a multi-study investigation of workers at Amazon, a multinational e-commerce company based in Seattle, Washington, USA, and the mental health benefits associated with exposure to nature. Methods In Study 1, participants (n = 153) responded to a cross-sectional survey that assessed the association of self-reported visitation to an indoor company greenspace with psychological well-being including symptoms of depression, anxiety, positive and negative affect, and stress. In Study 2, a subset of participants from Study 1 (n = 33) completed multiple surveys in a 2-week period that assessed the association of the naturalness of their current environments with their state levels of psychological well-being. Results We found contact with more natural outdoor environments was significantly associated with reduced state anxiety, after adjusting for activity type, location, and participants’ trait levels of nature relatedness. Conclusions Findings demonstrate that nature contact in everyday life is significantly associated with decreased levels of state anxiety. More research is needed to investigate the role of nature contact as a potential intervention in the workplace for improved mental health.
Read moreNature Versus Urban Hiking for Veterans with Post-Traumatic Stress Disorder: A Pilot Randomized Trial Conducted in the Pacific Northwest USA
Figure 1. Conceptual model Objectives To evaluate feasibility and acceptability of a group-based nature recreation intervention (nature hiking) and control condition (urban hiking) for military Veterans with post-traumatic stress disorder (PTSD). Design and setting A pilot randomised controlled trial conducted in the US Pacific Northwest. Participants Veterans with PTSD due to any cause. Interventions Twenty-six participants were randomised to a 12-week intervention involving either six nature hikes (n=13) or six urban hikes (n=13). Primary and Secondary Outcome Measures Feasibility was assessed based on recruitment, retention and attendance. Questionnaires and post-intervention qualitative interviews were conducted to explore intervention acceptability. Questionnaires assessing acceptability and outcomes planned for the future trial (eg, PTSD symptoms) were collected at baseline, 6 weeks, 12 weeks (immediately after the final hike) and 24 weeks follow-up. Results Of 415 people assessed for eligibility/interest, 97 were interested and passed preliminary eligibility screening, and 26 were randomised. Mean completion of all questionnaires was 91% among those in the nature hiking group and 68% in those in the urban hiking group. Over the course of the intervention, participants in the nature and urban groups attended an average of 56% and 58%, respectively, of scheduled hikes. Acceptability of both urban and nature hikes was high; over 70% reported a positive rating (ie, good/excellent) for the study communication, as well as hike locations, distance and pace. Median PTSD symptom scores (PTSD Checklist-5) improved more at 12 weeks and 24 weeks among those in the nature versus urban hiking group. Conclusions This pilot study largely confirmed the feasibility and acceptability of nature hiking as a potential treatment for Veterans with PTSD. Adaptations will be needed to improve recruitment and increase hike attendance for a future randomised controlled trial to effectively test and isolate the ways in which nature contact, physical activity and social support conferred by the group impact outcomes. Trial Registration Number NCT03997344
Read morePsychological Impacts from COVID-19 Among University Students
Figure 1. COVID-19 psychological impact profiles derived from z-scores of eight items reduced to two factors using data from college students across the United States (n = 2,534). Background University students are increasingly recognized as a vulnerable population, suffering from higher levels of anxiety, depression, substance abuse, and disordered eating compared to the general population. Therefore, when the nature of their educational experience radically changes—such as sheltering in place during the COVID-19 pandemic—the burden on the mental health of this vulnerable population is amplified. The objectives of this study are to 1) identify the array of psychological impacts COVID-19 has on students, 2) develop profiles to characterize students’ anticipated levels of psychological impact during the pandemic, and 3) evaluate potential sociodemographic, lifestyle-related, and awareness of people infected with COVID-19 risk factors that could make students more likely to experience these impacts. Methods Cross-sectional data were collected through web-based questionnaires from seven U.S. universities. Representative and convenience sampling was used to invite students to complete the questionnaires in mid-March to early-May 2020, when most coronavirus-related sheltering in place orders were in effect. We received 2,534 completed responses, of which 61% were from women, 79% from non-Hispanic Whites, and 20% from graduate students. Results Exploratory factor analysis on close-ended responses resulted in two latent constructs, which we used to identify profiles of students with latent profile analysis, including high (45% of sample), moderate (40%), and low (14%) levels of psychological impact. Bivariate associations showed students who were women, were non-Hispanic Asian, in fair/poor health, of below-average relative family income, or who knew someone infected with COVID-19 experienced higher levels of psychological impact. Students who were non-Hispanic White, above-average social class, spent at least two hours outside, or less than eight hours on electronic screens were likely to experience lower levels of psychological impact. Multivariate modeling (mixed-effects logistic regression) showed that being a woman, having fair/poor general health status, being 18 to 24 years old, spending 8 or more hours on screens daily, and knowing someone infected predicted higher levels of psychological impact when risk factors were considered simultaneously. Conclusion Inadequate efforts to recognize and address college students’ mental health challenges, especially during a pandemic, could have long-term consequences on their health and education.
Read moreAffective Reactions to Losses and Gains in Biodiversity: Testing a Prospect Theory Approach
Figure 1. Prospect theory predictions applied to reports of biodiversity change in the current studies. Recent reports have presented evidence of dramatic biodiversity declines. Despite the threat posed by such losses we know little about people’s reactions to such information, or rarer ‘bright spot’ stories of localised recovery. We explored these issues through the lens of prospect theory, testing three aspects: a) reference dependence, b) loss aversion, and c) diminishing sensitivity. Study 1 (n = 393) presented US participants with a hypothetical ecological survey reporting changes in bird species at a key site between 1996 and 2016 using a 2 (Baseline species richness: Low/high) x 2 (Change direction: Loss/gain) x 4 (Change magnitude: 5/10/15/20 species) between-participants design. Study 2 (n = 570) used the same design but focused on marine species richness among a UK sample. Responses were measured using a version of the Scale of Positive and Negative Experience. Both studies found evidence of reference dependence, but not loss aversion. In fact both studies found that reactions to biodiversity gains were stronger than equivalent losses; gains ‘loomed larger’ than losses. There was little evidence of diminishing sensitivity; scope insensitivity was the predominant pattern for losses and gains across both studies. Although those high in nature relatedness reacted more strongly to losses and gains, relatedness did not moderate any effects. Results suggest that communicators should not be surprised if reports of biodiversity declines do not have the impact they hoped, and that weaving in ‘bright spot’ stories may help people engage with the broader issues.
Read moreResearch Note: Residential Distance and Recreational Visits to Coastal and Inland Blue Spaces in Eighteen Countries
Figure 1. Given residential locations (correct to three decimal degrees) of the 15,216 respondents included in analysis. The map of Spain includes respondents resident in the autonomous city of Melilla. Respondents resident in the Canary Islands, Azores, and Madeira are not displayed. Varied categorisations of residential distance to bluespace in population health studies make comparisons difficult. Using survey data from eighteen countries, we modelled relationships between residential distance to blue spaces (coasts, lakes, and rivers), and self-reported recreational visits to these environments at least weekly, with penalised regression splines. We observed exponential declines in visit probability with increasing distance to all three environments and demonstrated the utility of derived categorisations. These categories may be broadly applicable in future research where the assumed underlying mechanism between residential distance to a blue space and a health outcome is direct recreational contact.
Read moreResults From an 18 Country Cross-Sectional Study Examining Experiences of Nature for People with Common Mental Health Disorders
Figure 1. Estimated anxiety (unstandardized coefficients, 95% Confidence Intervals) during last nature visit as a function of perceived social pressure for each CMD group. Estimates are based on models controlling for: sex, age, perceived financial strain, employment status, marital status, number of children in household, having a long-term limiting illness, smoking status, alcohol use seasonal wave and country; and visit-related factors, number of companions, presence of dog, transport mode, travel time, visit duration, and anxiety ‘yesterday’. Exposure to natural environments is associated with a lower risk of common mental health disorders (CMDs), such as depression and anxiety, but we know little about nature-related motivations, practices and experiences of those already experiencing CMDs. We used data from an 18-country survey to explore these issues (n = 18,838), taking self-reported doctor-prescribed medication for depression and/or anxiety as an indicator of a CMD (n = 2698, 14%). Intrinsic motivation for visiting nature was high for all, though slightly lower for those with CMDs. Most individuals with a CMD reported visiting nature ≥ once a week. Although perceived social pressure to visit nature was associated with higher visit likelihood, it was also associated with lower intrinsic motivation, lower visit happiness and higher visit anxiety. Individuals with CMDs seem to be using nature for self-management, but ‘green prescription’ programmes need to be sensitive, and avoid undermining intrinsic motivation and nature-based experiences.
Read moreThe Affective Benefits of Nature Exposure: What’s Nature Got to Do with It?
Figure 1. Hypotheses & analyses overview for study 2. Nature interactions have been demonstrated to produce reliable affective benefits. While adults demonstrate strong preferences for natural environments over urban ones, it is not clear whether these affective benefits result from exposure to nature stimuli per se, or result from viewing a highly preferred stimulus. In one set of studies (Study 1 and 2), state affect before and after image viewing was examined as a function of both preference level (high, low, very high, or very low aesthetic value) and environment type (nature or urban). When aesthetic value was matched, no differences in affect change were found between environments. However, affect change was predicted by individual participants’ ratings for the images. The largest affective benefits occurred after viewing very high aesthetic nature images, but Study 2 lacked an equivalently preferred urban image set. In a second set of studies (Study 3 and 4), new sets of very highly preferred images in categories other than nature scenes (urban scenes and animals) were employed. As before, individual differences in preference for the images (but not image category) was predictive of changes in affect. In Study 5, the nature and urban images from Study 1 were rated on beauty to assess whether the stimuli’s preference ratings were capturing anything other than simple aesthetics. Results showed that beauty/aesthetics and preference (‘liking’) were nearly identical. Lastly, a replication of Study 2 (Study 6) was conducted to test whether priming preference accounted for these benefits, but this was not the case. Together, these results suggest that nature improves affective state because it is such a highly preferred environment.
Read moreHealth Benefits of Contact With Nature
Sara Perrins and Dr. Gregory Bratman of the University of Washington, College of Forest Resources, prepared this report for the Recreation and Conservation Office. This study was directed by the Washington State Legislature in Section 304 (3) of the 2018 operating budget, as stated: Section 304 (3) $125,000 of the general fund—state appropriation for fiscal year 2019 is provided solely for the board to conduct or contract for a study of the economic and health benefits of trail-based activities, including hiking, walking, and bicycling. The information gathered will assist in decision-making regarding the allocation of dedicated resources and investment in Washington’s trail networks. Additionally, the information will aid in increasing and leveraging economic benefits in the development of public-private partnerships aimed at stewardship and growth connected to Washington’s trail networks. The study may include, but is not limited to, analysis of the number of people in the state who hike, bike, and walk annually, economic contribution, environmental and social benefits, and mental and physical health outcomes. The study may also include regional case studies. As appropriate, the analysis must incorporate data from the state comprehensive outdoor recreation plan and federal initiatives to integrate outdoor recreation into GDP accounting. To allow for a collaborative process, the board must create an advisory committee of appropriate agencies and stakeholders, including hiking and bicycling groups. The board must report the results of the study to the appropriate fiscal and policy committees of the legislature by October 1, 2019. This specific look at health effects and nature contact accompanies an economic study conducted by EcoNorthwest in 2019 titled Economic, Environmental, and Social Benefits of Recreation Trails in Washington State.
Read moreNature and Mental Health: An Ecosystem Service Perspective
Figure 1. A conceptual model for mental health as an ecosystem service. A growing body of empirical evidence is revealing the value of nature experience for mental health. With rapid urbanization and declines in human contact with nature globally, crucial decisions must be made about how to preserve and enhance opportunities for nature experience. Here, we first provide points of consensus across the natural, social, and health sciences on the impacts of nature experience on cognitive functioning, emotional well-being, and other dimensions of mental health. We then show how ecosystem service assessments can be expanded to include mental health, and provide a heuristic, conceptual model for doing so.
Read moreSocial-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 moreNature Contact and Human Health: A Research Agenda
Figure 1. A spectrum of forms of nature contact. Background At a time of increasing disconnectedness from nature, scientific interest in the potential health benefits of nature contact has grown. Research in recent decades has yielded substantial evidence, but large gaps remain in our understanding. Objectives We propose a research agenda on nature contact and health, identifying principal domains of research and key questions that, if answered, would provide the basis for evidence-based public health interventions. Discussion We identify research questions in seven domains: a) mechanistic biomedical studies; b) exposure science; c) epidemiology of health benefits; d) diversity and equity considerations; e) technological nature; f) economic and policy studies; and g) implementation science. Conclusions Nature contact may offer a range of human health benefits. Although much evidence is already available, much remains unknown. A robust research effort, guided by a focus on key unanswered questions, has the potential to yield high-impact, consequential public health insights.
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 moreThe Impacts of Nature Experience on Human Cognitive Function and Mental Health
Scholars spanning a variety of disciplines have studied the ways in which contact with natural environments may impact human well-being. We review the effects of such nature experience on human cognitive function and mental health, synthesizing work from environmental psychology, urban planning, the medical literature, and landscape aesthetics. We provide an overview of the prevailing explanatory theories of these effects, the ways in which exposure to nature has been considered, and the role that individuals’ preferences for nature may play in the impact of the environment on psychological functioning. Drawing from the highly productive but disparate programs of research in this area, we conclude by proposing a system of categorization for different types of nature experience. We also outline key questions for future work, including further inquiry into which elements of the natural environment may have impacts on cognitive function and mental health; what the most effective type, duration, and frequency of contact may be; and what the possible neural mechanisms are that could be responsible for the documented effects.
Read moreThe Benefits of Nature Experience: Improved Affect and Cognition
Figure 2. Affective impact of nature experience. Difference scores are used to compare performance from before the walk to performance afterward (negative values indicate a decrease after the walk, while positive values indicate an increase). Each panel depicts these difference scores for the urban and nature groups separately on one of the four affective measures: (A) anxiety, (B) rumination, (C) negative affect, and (D) positive affect. Error bars depict standard error (SE) values. Highlights Nature experience produced clear benefits for affect (e.g., decrease in anxiety and rumination). Nature experience produced some benefits for cognition (complex working memory span task). Supports the idea that exposure to natural greenspace can improve affect and cognition. This study investigated the impact of nature experience on affect and cognition. We randomly assigned sixty participants to a 50-min walk in either a natural or an urban environment in and around Stanford, California. Before and after their walk, participants completed a series of psychological assessments of affective and cognitive functioning. Compared to the urban walk, the nature walk resulted in affective benefits (decreased anxiety, rumination, and negative affect, and preservation of positive affect) as well as cognitive benefits (increased working memory performance). This study extends previous research by demonstrating additional benefits of nature experience on affect and cognition through assessments of anxiety, rumination, and a complex measure of working memory (operation span task). These findings further our understanding of the influence of relatively brief nature experiences on affect and cognition, and help to lay the foundation for future research on the mechanisms underlying these effects. Related Media Nature May Be Key to Strengthening Our Attention (November 28, 2023)
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