Urban Forestry & Urban Greening最新文献

Public perceptions of urban green space (UGS) qualities affect people’s decisions to go to such spaces. Although the multidimensional characteristics of public perceptions towards UGSs are widely recognised, they are context-dependent, and the internal structure of these attributes remains unclear. This research aims to explore the multidimensional attributes of the perceived qualities of UGSs in the context of modern China and uncover the internal structure of these attributes. A qualitative analysis combined with a quantitative survey was conducted to study how people perceive the qualities of three typical UGSs in a Chinese city. Our dataset consisted of 10,485 online review records left by UGS users and 9 semistructured interviews, which helped us identify the attributes of the perceived qualities of UGSs from the perspective of users rather than from the perspective of planners or policy makers. Results showed that people care about service quality, intelligent management and location, which is slightly different from the concept of distance-based location. These perceived qualities have a hierarchical internal structure and reveal people’s decision-making process from meeting their basic needs to evoking their highest level of sense of place. Policy implications and suggestions were also provided based on the results.

Species in humid, tropical regions frequently experience dangerously high heat. The danger of high temperatures is especially pronounced in cities due to the urban heat island effect. Trees can greatly reduce surface temperatures and mitigate the urban heat island effect through evapotranspiration and by reflecting solar radiation before it is absorbed by impervious surfaces. However, trees may also be physiologically susceptible to the effects of climate change as high temperatures exceed their physiological limits. In this study, we assessed how the urban tree community in subtropical Miami (Florida, USA) will be impacted by climate warming and how impacts will differ between native and exotic tree species. We calculated the thermal safety margin (TSM) in Miami for each of 235 tree species as the difference between the maximum temperature experienced by a species within its range and the current and future (2100) projected maximum temperature in the city. We also combined TSMs, a metric of resilience to heat, with each species’ drought, wind, and salt tolerance to identify species that are resilient to multiple relevant stressors. We found that by 2100 Miami will be too hot for 16–41 % of the tree species currently planted in the city, depending on the climate change scenario. Native tree species will be disproportionately impacted compared to exotics, likely because most exotic species originate in the tropics, whereas most species native to Miami are primarily subtropical or temperate. The species that are more resilient to multiple stressors include mostly native species, several of which are ideal shade trees. Urban greening initiatives should carefully consider tree plantings to optimize the long-term health of urban tree communities and the services that they can provide to cities in the future.

Worldwide, low-income and racial/ethnic minority communities tend to have a lower provision of green space than less disadvantaged groups. To address these inequities, some non-governmental organizations (NGOs) have worked on projects, such as new parks in underserved communities, and policy change, such as green space funding prioritizing underserved areas. To date, limited research has examined the landscape of NGOs working to advance green space equity via policy change. In this paper, we studied what kind of NGOs engage in green space equity policy advocacy in the US. We used topic modeling, keywords-in-context, and inferential statistics to analyze grant applications for a national initiative to fund green space equity advocacy, the first and only of its kind. We found that NGOs also advocate for several interrelated topics related to green space equity (e.g., environmental issues, social services), engage numerous policy actors in campaigns (e.g., politicians, youth), and use other strategies such as coalitions, power building, and research. NGOs working to address green space inequities also need to contend with other systemic issues affecting underserved communities (e.g., poverty, health disparities). Our findings can inform the work of public and philanthropic funders, local governments seeking partnerships with NGOs, and NGOs themselves.

Vegetation on school grounds has several values and functions that contribute to aspects as children’s well-being, pedagogy and microclimate among others. Research on school ground vegetation is conducted within many different research fields and deals with a variety of research themes. A systematic review was conducted to explore scientific literature on the topic of school ground vegetation broadly, enabling an overview of this diverse field and the discovery of trends or gaps within this research. The objective was also to investigate to what extent actual vegetation is in focus in this literature. The results highlight a low level of specificity when describing vegetation, concerning both spatial aspects and content, with general terms such as “nature” or vegetation types (trees/shrubs/grass, etc.) being common, leading to difficulties in interpretation and synthesis. A multitude of themes are present, describing different research foci. Several themes show limited interaction with other themes, such as the theme “microclimate”, which may be of notable relevance for future research because of global warming. More coherence in how to describe vegetation on school grounds is needed to compare results. Also, more connections between research themes could address research gaps and be beneficial for future research endeavours.

Because of the high costs associated with data sources, urban policymakers struggle to employ cost-effective remote sensing methods for evaluating trees and their potential contributions to atmospheric Carbon Stock (CS). While free data sources like Copernicus Sentinel satellite data could be explored, there are a few studies illustrating its potential for mapping urban tree C. Here, the Sentinel 2 (S2)-derived Normalized Difference Vegetation Index (NDVI) was used to model CS for street trees in Brussels. In parallel, the WorldView 3 (WV3)-derived NDVI layer was also used for a similar study area to compare the CS mapping outcomes regarding dominant tree species. The accuracy level was around 90 % (R²=0.89, r=0.94, and RMSE= 97 kg) in the case of WV3 data, whereas it was about 60 % (R²=0.60, r=0.79, and RMSE = 189.6 kg), even with a coarse resolution regarding the S2 data. This study also shows the strength and scope of using S2 data over WV3 data, illustrating the convenience in terms of accuracy and cost-effectiveness compared to existing methods. The applied methodology could be utilized to monitor urban trees and predict the level of possible carbon sequestration, even considering a larger city like Brussels with a complex agglomeration. It could be a solid additional support for the authorities of European towns and developing countries, especially in terms of being cost-efficient and readily embraced by users.

Uneven access to greenspaces or visible greenness is an environmental justice (EJ) issue. In this paper, we use a social equity lens to develop geospatial models that measure convenient walking access to urban greenspaces such as parks and street-level green exposure en route to greenspaces. We utilized earth science, geospatial, and demographic datasets to develop two models—Greenspace Accessibility and Visible Greenness Exposure—and applied them in Camden and Jersey City, USA, two communities experiencing environmental injustices. Modeling results show that greenspace accessibility is a concern in both cities, with Jersey City experiencing more prominent disparities. We observed significant positive relationships in Camden between greenspace accessibility and two EJ variables: Black segregation and Hispanic segregation. Most streets in both cities have poor greenness exposure, although Jersey City faces higher inequality compared to Camden. We also observed significant negative relationships in Jersey City between street-level greenness exposure and low-income populations. We conclude the paper by explaining the implications of our findings for greenspace planning and policymaking.

Prior research has indicated lower crime rates in areas with greater tree canopy cover predominantly in the Global North. There are few studies from the Global South, and more specifically in Latin America. Given the high prevalence of crime in Latin American cities, the need to address social and environmental inequalities using nature-based solutions is urgent. This study examines crime and tree canopy cover through a series of spatial analyses for São Paulo city, Brazil, while controlling for potential confounders. We tested six levels of data aggregation that were combined with three different crime types and two denominators of crime, to account for spurious findings from Modifiable Areal Unit Problems (MAUP). Of the 36 models, a majority of 27 models (75 %) indicate a negative relationship between crime and tree cover canopy, while 4 models (11 %) show a positive correlation, and 5 models (14 %) suggest no statistically significant relationship. Our best models allow us to infer that 10 % greater tree canopy cover is associated with a 1.20 % fewer property, personal and total reported crimes, with statistical significance at the p < 0.001 level. These findings support our hypothesis that there is a negative relationship between tree canopy cover and crime, with a stronger association observed for property crime than personal or total crime. The negative relationship persisted independently of the level of data aggregation, crime types, crime denominator and spatial models specifications (lag and SARMA), avoiding statistical bias of MAUP. The results follow the literature that have observed tree cover associated with lower crime rates, for different types of crime, while adding a new climatic and cultural context to the evidence base.

Decreased exposure to environmental microbes among urbanites is generally thought to contribute to the high incidence of several immune-mediated diseases. Urban landscaping materials that provide microbiological diversity and contain health-associated microbes, such as proteobacterial and mycobacterial taxa, could modulate the risk of the immune-mediated diseases. The aim of the current study was to develop soils that contain health-associated microbiota and are suitable for urban landscaping. Therefore, the potential of forestry- and agriculture-derived supplements in urban greening was investigated. Commercially available, peat-based lawn soil (standard substrate) was enriched with boreal forestry side streams (conifer needles, cones, pine bark, alnus leaves, moss debris, reed and manure), moss or side-stream based products (biochar, composted agricultural waste). The microbial communities of the standard and enriched substrates were followed in two year-long studies in which sod and grass were grown outdoors and indoors. Moss, conifer needles and reed retainded and increased the relative abundance of the phylum Proteobacteria and its classes, while Alnus litter and conifer needles supported the relative abundance of Mycobacterium. Temporal shifts in the relative abundance and richness of previously health-associated bacteria were evident. The method of enriching lawn soil with side streams appears to elicit desired shifts in health-associated microbial taxa. The results indicate that several agricultural and forestry side streams are suitable for shaping health-associated microbiota in commercially available soil. Further studies to explore the potential of side streams in immunomodulatory urban greening are recommended.

Human activities, particularly urbanization, profoundly impact ecosystems often resulting in biotic homogenization. Whether or not urban landscapes can sustain diverse pollinator and plant communities is an important question to be addressed. Here, we investigated the influence of urbanization on plant-hummingbird interaction networks in a large tropical city, Belo Horizonte, Brazil. We recorded 13198 legitimate interactions between seven hummingbirds and 57 plant species across 12 local networks. Urban landscapes exhibited predominantly generalized networks, maintaining this pattern across varying vegetation cover and floral resource abundance. Although some functionally specialized hummingbirds with long bills were recorded performing more specialized interactions, urban environments did not generally support specialized networks. Nevertheless, network specialization did increase with the proportion of native nectar plants, emphasizing their importance for maintaining some specialized interactions. Furthermore, we observed a positive effect of plant richness, but not of flower abundance, on hummingbird abundance, indicating that it is not only the amount of flowers, but the diversity of floral resources that may be a key factor in maintaining hummingbirds. Therefore, promoting a diverse assemblage of native plants in urban green areas is crucial for sustainable pollinator communities. Our study highlights that while a biodiverse urban landscape will require careful urban vegetation planning considering both floral resource diversity and availability, vegetation cover per se may not be sufficient to mitigate the negative impacts of urbanization. Maintaining a diverse vegetation with different life forms, flowering phenology, and especially of native plants across the urban landscape is needed to create welcoming spaces for pollinators.