Urban greenspace access,uses, and values: A case study of user perceptions in metropolitan ravine parks

Urban greenspaces provide critical ecosystem services to urban area residents. While urban greenspaces provide a range of ecosystem services, cultural ecosystem services may be the most prominent to residents. Cultural ecosystem services provide benefits through educational, recreational, social, and spiritual opportunities. More knowledge is required about greenspace users’ perspectives of their local greenspaces, which will enrich park planners’ knowledge of the preferences, concerns, and potential points of conflict that greenspace users experience. To help increase this knowledge, we conducted a survey with closed and open-ended questions and supported it with a park audit and photographic evidence. As a case study, data were collected in six ravine parks in the City of Toronto, Canada. Ravine parks were of particular interest as they are a unique form of socio-ecological greenspace that have varied management goals which on occasion may differ from some user preferences and values. Quantitative data were analyzed with analysis of variance and chi-square tests of independence, and qualitative data were analyzed with conventional qualitative content analysis. Our results highlight that current ravine park users vary widely in their characteristics and the values they pursue through their park access. While the range of ravine park types accommodates some of this variability, there is also conflict between ravine park users with different values and expectations. We are offering a series of recommendations addressing these findings and hope that insights from this deep and rich case study will be of use to other forested, urban greenspaces under similar conditions.     

Multiple factors shape the interaction of people with urban greenspace: Sweden as a case study

This study identifies and analyses multiple factors that impact people’s interactions with urban greenspace in Sweden. An unrestricted, self-selected online survey was used to collect the data. The survey questions were related to individual characteristics of respondents, including socio-demographic characteristics, self-reported nature connectedness, and self-reported constraints to greenspace usage; perceived characteristics of urban greenspace, including its availability, quality, and accessibility, and benefits and problems; and preferences of respondents regarding types of urban greenspace and activities. Additionally, several spatially explicit variables were included in the analysis. A total of 2806 respondents from 208 (of 290) municipalities completed the survey. Our findings indicate that greenspace users are highly heterogeneous and utilise diverse green spaces along the urban-peri-urban gradient for various benefits. The statistical analyses identified 61 explanatory variables that affect the frequency of interactions with urban greenspace. In addition, we identify key factors that shape critical differences between frequent and infrequent urban users, such as nature connectedness, perceptions of urban greenspace functions, and their perceived accessibility. Our results highlight the complex challenge facing urban planners and managers of green spaces, who have to consider and integrate a vast array of factors influencing the willingness of increasingly diverse urban populations to interact with greenspace.     

Varying age-gender associations between body mass index and urban greenspace

Urban greenspace benefits urbanites in numerous ways ranging from regulating flooding, air quality, and local climate to providing opportunities for exercise and relaxation. These benefits may influence human health. Greenspace, for example, may facilitate exercise, thereby helping to reduce body mass index (BMI) and combat obesity, a current epidemic of great public health concern. Little evidence exists to support this assertion, however, and we lack a full understanding of the mechanisms whereby this relationship operates, the populations for whom greenspace is linked to weight status, and the aspects of urban greenspace that are linked to weight status. This study seeks to identify relationships among the composition and arrangement of greenspace and BMI for different populations using regression models for eight age and gender groups in Cleveland, Ohio, US. We find that several greenspace variables are related to BMI for women under 65 years and males under 51 years, but not for older groups, and that the aspects and types of greenspace that are significantly related to BMI vary among groups. Relationships between greenspace attributes and BMI are generally stronger for female groups and for younger groups. Providing access to greenspace with particular attributes such as greenspaces with water, canopy cover, or connected greenspaces could support a healthy weight status for some populations, but these attributes are not consistent across age and gender groups. These results could help to inform policy aimed at designing urban greenspace to benefit the health of different population subgroups.     

The influence of bird information,attitudes, and demographics on public preferences toward urban green spaces: The case of Montpellier,France

Urban sprawl is a major driving force of land use change. To develop strategies for sustainable urban development, planners need suitable indicators, one of which is the quality and quantity of green spaces in a city. To implement conservation strategies for urban areas, an assessment of how people perceive green spaces is required. The aim of this paper is to analyze: (1) willingness to contribute financially to two types of urban green spaces, (2) how people's attitudinal and socio-economic characteristics affect this willingness, and (3) to what extent this willingness is affected by the information that green spaces are important for avifauna conservation. We found that 72% of the respondents in Montpellier, France preferred natural (versus ornamental) green spaces and wanted them to be increased in the city. To achieve this, 52% of the respondents were willing to pay a percentage of their monthly household income. Giving information about birds to residents increased their preferences (especially for those having a “favourable” attitude for urban fauna) for “natural” green spaces and increased willingness to pay for green spaces among people using green spaces at least monthly. For people less concerned about nature, there was no such effect of providing bird information on preferences for green spaces.     

The impact of greenspace size on the extent of local nocturnal air temperature cooling in London

Urban greenspaces can provide a significant cooling service, which extends beyond the greenspace boundaries. Consequently, greenspaces are recognised for their ability to locally reduce the urban heat island, a phenomenon that has negative implications for the thermal comfort and health of urban citizens. However, the amount of cooling provided by a greenspace and the distance over which that cooling extends depend on factors such as greenspace size and characteristics. Based on data collected in and around eight London greenspaces, with areas ranging from 0.2 to 12.1 ha, this work models the distance and magnitude of cooling provided by each greenspace and defines the relationships between cooling extent and the size of greenspace or the areas of tree canopy and grass. Such data, illustrating the value of expanding the area of urban greenspaces and explaining how cooling relates to greenspace size/coverage characteristics, will be of use to urban planners and climatologists concerned with finding solutions to the urban heat island. Modelling was statistically valid on calm warm nights (with mean air temperatures ≥10 °C and wind speed ≤3 m s⁻¹). On those nights, cooling distance increased linearly with increasing area of greenspace, tree canopy and grass, but the relationship between those factors and the amount of cooling was non-linear. Cooling distance was most strongly related with tree canopy whereas the amount of cooling was most strongly linked to the grass coverage. Our results suggest that a comprehensive cooling service on calm warm nights within cities with similar climate/characteristics to London may come from greenspaces with 3–5 ha, situated 100–150 m apart.     

Pocket parks in a compact city: how do birds respond to increasing residential density?

The desire to improve urban sustainability is motivating many city planners to adopt growth strategies that increase residential density, leading to substantial changes to urban landscapes. What effect this change will have on biodiversity remains unclear, but it is expected that the role of public greenspace in providing wildlife habitat will become critical. We explored the role of urban “pocket parks” as habitat for birds, and how this role changed with increasing residential density in the surrounding neighbourhood. We found that parks in neighbourhoods with high levels of public greenspace (corresponding to less residential land) supported more bird species and individuals overall, and more woodland-dependent species, insectivores and hollow-nesters. Total greenspace area was more important (included in the best ranked models for all bird responses) than the configuration (number, average size and connectivity) of greenspace patches. The majority of species were common suburban birds, indicating that species we assume are tolerant to urban areas will be negatively affected by increasing residential density. Parks form part of an interconnected network of urban open space. For parks to continue to support a diverse native bird community, the network must be viewed, managed, and maintained in its entirety. We suggest three key management actions to improve the bird diversity values of urban greenspaces in compact cities: (1) Increase urban greenspace cover in residential neighbourhoods. (2) Increase vegetation structure in greenspace. (3) Encourage homeowners to plant trees and shrubs.     

Exploring public preferences and preference heterogeneity for green and blue infrastructure in urban green spaces

Green and blue urban infrastructure (GBI) has many positive functions often not recognised by residents (e.g., microclimate regulation, water retention, etc.). The question for urban planners who are aware of these functions when planning new GBI elements or revitalising existing GBI is how much they need to account for the preference heterogeneity of locals, who typically consider only aesthetic and recreational value. This study uses data from a discrete choice experiment among residents of the medium-sized Czech city of Liberec to reveal which combinations of nature-based or semi-natural GBI and recreational facilities respondents prefer and how strong their preferences are in terms of their willingness to pay. Overall, study respondents preferred nature-based GBI to semi-natural ones. A mixed-latent class model identified two groups of respondents who differ in preferences, trade-offs, and socio-demographic characteristics: (i) mostly older educated women who prefer nature-based elements and enjoy park infrastructure; (ii) mostly less educated men who dislike urban gardens and semi-natural streams and do not value park infrastructure. Based on the results, we recommend that spatial planners and green space managers design and implement more nature-based elements in Liberec, which are in line with the respondents’ preferences.     

Factors that enhance or hinder social cohesion in urban greenspaces: A literature review

Urban greenspaces--including city parks, forests, and gardens--can provide many benefits that impact human wellbeing. One such aspect of wellbeing is social cohesion, which is broadly defined as the combined reasons to stay in a particular community. Although there is an increase in studies connecting human wellbeing, social cohesion, and urban greenspace, there is limited synthesis of the three concepts. The purpose of this paper is to review how social cohesion has been used, defined, and measured in the scholarly literature. In addition, we assess the factors that hinder or enhance social cohesion in urban greenspace and opportunities for future research. We conducted a systematic literature review using the PRISMA procedures. After doing a search with keywords, we read the abstracts of 1129 articles and selected 113 that met our inclusion criteria for final in-depth analysis. We provide an overview and conceptual diagram of the factors that enhance or hinder social cohesion in urban greenspaces. Although all of the analyzed articles included social cohesion as a variable or topic of interest, only 17 of those articles clearly defined and measured social cohesion. The most impactful ways to enhance social cohesion include reducing crime, improving maintenance, and having physical space and amenities for social gatherings that cater to various demographics. Likewise, studies suggest that the perceptions of safety, level of maintenance, accessibility, and efforts to be inclusive of diverse users including cultural activities and community engagement spaces were important to social cohesion. Overall, more research is needed to better understand social cohesion and urban greenspace in developing countries, and more in-depth analysis from the perspective of diverse urban residents who use these greenspaces. The results of this study have implications for designing and managing urban greenspaces to enhance social cohesion, inclusion, and overall human wellbeing.     

How does the presence of greenspace related to physical health issues in Indonesia?

There have been many studies associating various aspects of greenspaces with physical health. Very few of these investigations are available for developing countries such as Indonesia. Our study focused on evaluating the association between greenspace and the incidence rate of non-communicable diseases (NCDs) in terms of ischemic heart disease (IHD), diabetes mellitus (DM), rheumatoid arthritis (RA), and chronic kidney disease (CKD). Greenspace was presented by satellite-derived normalized difference vegetation index (NDVI) and forest-related green cover datasets to define exposures to the resolution of 250-m. The Institute for Health Metrics and Evaluation provided age and gender incident data of NCDs at the province level. A generalized additive mixed model coupled with sensitivity test was used to evaluate the exposure-outcome association. Stratified analyses were also employed. After adjusting for covariates, there was a significant negative association for incidence of NCDs and greenspace. We found that an interquartile unit increase of NDVI, and a percentage of forest were closely related to a decrease in the risk of NCDs by 0.3–9.4% and 0.6–6.2%, respectively. Stratified by exposure level, a greater effect of greenspace on reducing NCDs risk occurred in high exposure areas. Considering the socioeconomic factors, greenspace could influence on reducing NCD risks in high urbanization, low-high poverty, and low-high literacy areas. An increment unit of greenspace was associated with a decreased risk of NCDs. This study underscores important health benefits associated with exposures to nature supporting efforts to preserve greenspaces in Indonesia.     

Characterizing the provision and inequality of primary school greenspaces in China’s major cities based on multi-sensor remote sensing

Environmental and green justice problems occur globally, especially in cities with unequal access to urban greenspaces. Recently, inequality in school greenspaces has drawn growing attention, given the importance of campus green environments in young students’ health and academic performance. However, the commonly used Normalized Differences Vegetation Index (NDVI) method for measuring greenspace from satellite imagery is hindered by the saturation issue and tend to underestimate greenspace at high vegetation cover areas, causing large uncertainties in greenspace inequality studies at a national scale. Besides, despite the progress on the inequality of public greenspace exposure, our understandings of primary school greenspace provision and inequality, as well as the driving factors, for young students in a developing world (e.g., China) is still limited. To address these issues, we first adapted a spectral unmixing technique based on multi-sensor remote sensing for more accurate measurements of greenspace provision. Then, we evaluated the provision and inequality of greenspace for 19,681 primary schools in China’s 31 major cities and examined the driving factors using an integrated path analysis. Our findings revealed that: (1) Our proposed multi-sensor remote sensing-based method for greenspace measurement is reliable across our study area with a R² of 0.81 and RMSE of 0.14; in contrast, the traditional NDVI-based greenspace measurement saturated at the range of 0.7–1.0, leading to much lower accuracy (a R² of 0.72 and RMSE of 0.24). (2) Most of the cities under study had low to moderate levels of inequality in primary school greenspace (Gini index < 0.5), but the overall greenspace provision was relatively low; Five cities under study facing high inequality in greenspace exposure (Gini index ≥ 0.5) as well as low greenspace provision (mean fraction cover < 0.25). (3) The monthly maximum temperature and the mean cover of greenspace in primary schools were identified as variables directly affecting the inequality in primary school greenspace (R² = 0.76, p-value < 0.05), whereas the city-level government revenue manifests its effects through the mean cover of greenspace in primary schools and city-level mean greenspace cover. By developing a novel framework for examining the provision and inequality of greenspace in all primary schools in China’s major cities, our study provides valuable insights for designing and evaluating school greening programs in support of healthier learning environment development for next generations.     

Envisioning carbon-smart and just urban green infrastructure

To address the inter-connected climate and biodiversity crises, it is crucial to understand how multifunctional urban green infrastructure (UGI) is perceived to contribute to carbon neutrality, biodiversity, human well-being, and justice outcomes in cities. We explore how urban residents, including youth, associate carbon-related meanings with multifunctional UGI and how these meanings relate to co-benefits to biodiversity, well-being, and broader sustainability outcomes. Our findings are based on a survey distributed among urban residents of Helsinki, Finland (n = 487) and reveal how carbon-related meanings of UGI manifest at different levels of abstraction, agency, and scale, and incorporate community values and concerns attributed to the planning, features, functions, and transformational dimensions of UGI. Core carbon-related meanings of UGI emphasize either actions towards sustainability, carbon neutrality, biodiversity, or unfamiliarity towards such meanings. Perceived justice concerns and the socio-demographic contexts of the respondents covaried with carbon-related meanings associated with UGI. The results illustrate community perceptions of how it is not only possible, but rather expected, that multifunctional UGI is harnessed to tackle climate change, human well-being, and biodiversity loss in cities. Challenges for implementing the carbon-related benefits of UGI include navigating the different expectations placed on UGI and including residents with diverse socio-economic backgrounds during the process. Our findings contribute to a holistic understanding of how multifunctional UGI can help bridge policy agendas related to carbon neutrality, biodiversity protection, and human well-being that cities can implement when aiming for sustainable, just, and socially acceptable transitions towards a good Anthropocene.     

Greening residential quarters in China: What are the roles of urban form,socioeconomic factors,and biophysical context?

Residential greenspace has great intracity variations. Its driving factors have been widely investigated in Western countries (e.g., in Europe and North America), where residential areas are mostly privately owned, but few studies have examined the determinants of residential greenspace in China, where land is owned by the government. Taking the subtropical city of Changsha, China, as an example, this study mapped the percent green cover (PGC) in residential quarters with a fine-resolution satellite image. We also investigated its driving factors measured from multisource geospatial data. The results show that (1) the PGC in the residential quarters showed great spatial variation, with an average of 36.6% (0–85.7%) and a standard deviation of 18.3%. (2) Urban form, biophysical context, and socioeconomic factors together explained 49.18% of the variation in the PGC, and they independently explained 22.87%, 11.17%, and 2.31% of the variation, respectively. (3) Residential quarter size, PGC in the surrounding buffer zone, residential quarter age, housing value, and population density significantly and positively impact the PGC, while percent building cover, floor area ratio, and distance to city center had significant negative impacts. The strongest positive and negative impacts came from PGC in the surrounding buffer zone and percent building cover, respectively. Socioeconomic factors, the dominant driving factors in Western countries, show little impact on residential PGC. These findings expand our understanding of the intracity variation in greenspace coverage and the driving factors, which sheds light on the effective planning and management of urban greenspaces in China.     

Spatial preference heterogeneity in policies for improving urban green spaces

Urban green spaces (UGSs) enhance the quality of urban dwellers’ lives. Thus, efficient policies for improving UGSs—which should reflect urban residents’ needs—are necessary. Additionally, it is crucial to manage the spatial distribution of residents’ preferences to find regions that can produce greater utility within limited budgets. Using online surveys conducted in 2015, which obtained 414 valid responses, this study analyzed urban residents’ preferences for UGS improvement policies and investigated spatial preference heterogeneity for such policies in the planned city of Seongnam, South Korea. A mixed logit model was applied to analyze policy preferences, and the preference heterogeneity level was assessed by coefficient of variation. Additionally, hot spot analysis was performed to examine spatial heterogeneity. The Getis-ord Gi* was computed to identify the spatial clusters of the estimated coefficients and the marginal willingness to pay (WTP). The results indicated a high preference for enhancing quality and connectivity. While the results showed that preference heterogeneity existed in each UGS improvement policy, heterogeneity levels differed per attribute. Statistically significant local spatial clusters of estimated coefficients and marginal WTP were observed for each UGS improvement policy despite global autocorrelation being insignificant. It was observed that estimate coefficients with low coefficient of variation can make extensive spatial clusters; otherwise, the opposite trend might occur. Additionally, marginal WTP hot spots did not change according to attribute but appeared in similar locations. Therefore, spatial heterogeneity analysis is necessary to manage UGSs with higher net utilities given limited budgets. These findings will ensure the satisfaction of all urban residents by identifying their preferences for UGS policies. They will also help prioritize cost-effective implementation of policy considering spatial preference heterogeneity.     

Urban agriculture and policy: Mitigating urban negative externalities

Agriculture and urban agglomerations can be combined in different perspectives, including building-integrated food production. Indeed, urban agriculture is less concerned with helping urban communities achieve food self-sufficiency and more concerned with strengthening urban inhabitants differently. "Different" signifies multifunctional forms of access to fresh and nutritious vegetables, food bill reduction, personal well-being, and user-friendly agriculture from socioeconomic perspectives. The study estimated willingness to pay and the value of socioeconomic benefits of urban agriculture practices. A choice experiment was performed in Colombo, Sri Lanka's most urbanized district in 2020. The data were estimated using the random parameter logit model. Positive and significant contributions to urban agriculture related to the utility of urban agriculture practitioners and non-practitioners were evident. The socioeconomic value of urban agriculture benefits generated is equivalent to USD 136,400 per community practices urban agriculture. Urban agriculture thus reveals its vitality as a tool for mitigating the negative impacts of urbanization. The research advocates Colombo municipality to actively encourage urban agriculture by including it in their planning policies.     

Informal urban greenspace: A typology and trilingual systematic review of its role for urban residents and trends in the literature

Urban greenspace is vital in fulfilling people's nature needs. Informal urban greenspace (IGS) such as vacant lots, street or railway verges and riverbanks is an often-overlooked part of the natural urban landscape. We lack a formal definition of IGS and a comprehensive review of knowledge about IGS and its role for urban residents. This paper advances a formal definition and typology of IGS that can be applied globally. Based on this definition, a total of 65 peer-reviewed papers in English (57), Japanese (7) and German (1) were reviewed. We analyzed this literature for its temporal trends, spatial patterns, studied IGS types, methods used and key authors, and summarized the individual research papers’ findings concerning IGS. Results show IGS plays an important role for urban residents, but also highlight limitations and problems in realizing IGS’ full potential. Research papers focused on perception, preferences, value and uses of IGS. Residents could distinguish between formal and informal greenspace. They preferred a medium level of human influence in IGS. The analysis of patterns in the literature reveals: a marked increase in publications in the last 20 years; a strong geographical bias towards the USA; and a lack of multi-type IGS studies including all IGS types. Publications outside of scholarly research papers also make valuable contributions to our understanding of IGS. Our results suggest IGS is emerging as an important sub-discipline of urban greening research.     

Mapping global urban greenspace: An analysis based on open land-cover data

Urban greenspace plays a positive role in improving the urban living environment, and thus extensive studies have paid attention to the mapping of urban greenspace for various applications. Recently, open and high-resolution land-cover (LC) data have been viewed as essential sources for urban greenspace mapping. However, few studies have performed a global-scale analysis; moreover, as there are commonly different LC types in an LC dataset, few studies have investigated how the definition or selection of different LC types as greenspace impacts urban greenspace mapping. Therefore, this study aims to investigate the spatial pattern of urban greenspace at a global scale and the impact on selecting different LC types for urban greenspace mapping. We employed two global open datasets (FROM-GLC10 and GHS-UCDB) and identified 13,079 global urban areas. Various LC types that potentially relate to urban greenspace and three different selections of LC types were analyzed. Results show that: 1) The spatial pattern of global urban greenspace may vary with the use of different selections; 2) The impact of whether or not to select each LC type as urban greenspace relates to not only the LC type itself but also the geographic locations. The findings may benefit urban planners and designers to select proper LC type(s) for urban greenspace studies.     

Association between urban greenspace,tree canopy cover and intentional deaths: An exploratory geospatial analysis

Greenspaces can provide restorative experiences, offer opportunities for outdoor recreation, and reduce mental fatigue; all of which may improve community health and safety. Yet few studies have examined the neighborhood-level benefits of greenspace in reducing violent deaths. This study explored the association between three distinct greenspace metrics: public greenspace quantity, public greenspace accessibility, neighborhood tree canopy cover, and intentional deaths (i.e., homicides and suicides). Generalized linear models and spatial error models investigated the association between greenspace, tree canopy and intentional deaths in three geographically distinct cities in North Carolina, USA. Results revealed that increased neighborhood greenspace accessibility and tree canopy cover were associated with reduced intentional deaths in all three urban areas. Neighborhood greenspace accessibility was the most protective factor across all study areas. The association between neighborhood greenspace accessibility and intentional deaths was more significant for non-firearm deaths as compared to firearm deaths, indicating that weapon type may be an important consideration for neighborhood greenspace interventions. Compared to predominantly White neighborhoods, predominantly Black neighborhoods had higher rates of homicide in Asheville and Durham and higher rates of suicide in Charlotte. Future policy and research should focus on improving equitable access to existing and future greenspaces, especially in primarily Black neighborhoods.     

Impact of mowing frequency on arthropod abundance and diversity in urban habitats: A meta-analysis

Urbanization is an important driver of global insect decline. Yet, recent studies have demonstrated the potential of greenspaces in cities to promote biodiversity conservation. One of many factors negatively affecting arthropods in urban areas are unsuitable habitats, as non-woody greenspaces predominantly consist of manicured lawns. Maintenance practices such as high mowing frequencies, can have direct and indirect negative impacts on the local flora and fauna. The present study examines the effects of different mowing regimes on arthropod abundance and diversity by conducting meta-analyses of studies assessing the effect of mowing on arthropod abundance (46 datasets) and taxa richness (23 datasets) in urban environments. Due to a geographical bias in the literature, only data from the temperate, northern hemisphere are analyzed. While our meta-analysis on arthropod abundance showed a medium positive effect (effect size: g = 0.54) of reduced mowing, the cumulative positive effect of reduced mowing on arthropod taxa richness was large (g = 1.25). Grouping the studies not only resulted in lower heterogeneity, but also showed that manicured lawns disproportionately favor the abundance of “pest” species as well as ground-dwelling arthropods. There was also a significantly higher abundance of winged insects on sites with reduced mowing as compared to arthropods without wings. Overall, the findings of the present meta-analysis strongly support the notion that a reduction in mowing frequencies in urban greenspaces benefits insect biodiversity.     

Exploring preferences for biodiversity and wild parks in Chinese cities: A conjoint analysis study in Hangzhou

There has been a transformation of value orientation from an anthropocentric to eco-centric view in Chinese urban park design. Biodiversity enhancement has been increasingly seen as a prioritised park design aim by landscape designers. This promotes the rise of a novel park style with wild, less manicured appearance in cities, which shows strong contrasts to the traditional park style with ornamental, manicured characteristics. However, in this urban park transformation process, people’s opinion has been almost ignored. This research investigated the importance of biodiversity compared with other relevant urban park attributes (i.e., Facilities, Woodlands, Maintenance, and Seasonal views) identified from preliminary focus groups. The research further predicted preferences between wild and traditional urban parks. Conjoint analysis was used to address these questions. Five urban park attributes (i.e., Biodiversity, Facilities, Woodlands, Maintenance, and Seasonal views) were included in the conjoint questionnaire survey. The survey (N = 187) was conducted with the public and ecology/landscape professionals in Hangzhou, China. Results showed that for professionals, biodiversity was the most important attribute relative to others; for the public, both facilities and biodiversity were the most important attributes. Preferences for the two park styles varied between the two groups: professionals preferred wild parks, whereas the public preferred traditional parks. Yet, public preferences for wild parks were enhanced by improving maintenance levels and providing recreation facilities. The study concluded the appreciation of biodiversity among both the public and professionals. Differences in professional preferences for wild parks compared to the public should be considered when professionals design wild parks in the future.     

Understanding spontaneous biodiversity in informal urban green spaces: A local-landscape filtering framework with a test on wall plants

In densely urbanized areas, small pockets of vegetated areas such as street verges, vacant lots, and walls can be rich in biodiversity. In spite of their small size, these ‘informal urban greenspaces’ can provide critical ecosystem services to urban residents. Maintaining and enhancing the provisioning of ecosystem services requires a systematic understanding of biodiversity patterns and drivers in informal urban green spaces. The ‘environmental filtering’ (a process of certain species selected by specific environmental conditions) concept in community ecology theory may serve as a useful tool for this goal. We tested a multi-scale filtering framework by examining the spontaneous plant diversity patterns (from 83 surveyed sites) on the vertical surfaces of the ancient city wall of Nanjing, China. We found that the variables representing local-habitat filtering (e.g., wall substrates and aspect) and landscape filtering (including spatial configuration of urban land cover, and nighttime light intensity surrounding the local habitats) can jointly explain substantial fractions of variations in taxonomic diversity (up to ca. 60%) and functional diversity (up to ca. 40%). The explanatory power was stronger in the repaired wall habitats than in the unrepaired counterparts, in line with the prediction that environmental filtering is more pronounced during the early stages of community assembly. While the strength of landscape filtering showed clear scale-dependency, its relative importance consistently outweighs local-habitat filtering across all study scales of 200–1600 m, suggesting that configuration of neighboring landscape context can play an important role in shaping local-scale biodiversity of informal urban green spaces. Our results have useful implications for the study, design, and management of informal urban green spaces. Well-tailored multi-scale filtering frameworks may contribute to understanding urban biodiversity patterns in a systematic way.