The potential of school green areas to improve urban green connectivity and multifunctionality

Urban green infrastructure supports resilience in cities and promotes sustainable resource management. Small green areas, including school green areas (SGAs), are an important component of urban green infrastructure, playing a key role in supplying cities with educational services. This article describes how SGAs can amplify an urban green area's connectivity and multifunctionality. The analysis was performed in Bucharest as a case study. A survey based on questionnaires was used to obtain data regarding green spaces within public schools. A total of 411 administrators from 461 public schools participated in the survey for a response rate of 89.1%. Information from the questionnaires was augmented with spatial data of SGAs and public green spaces, i.e., parks and city gardens. Using parametric and nonparametric statistical analysis, we first identified the variables that determine an SGA's presence and size. Potential connectivity assessment results showed that most of the schools that lack or have small-sized SGAs have the possibility to cover their green space deficit by developing activities within nearby public green spaces. A structural connectivity assessment of SGAs toward other public urban green areas revealed that SGAs are an important element of the urban environment by serving as stepping stones to species flow. The multifunctionality of the SGAs was emphasized through the educational services they provide, being involved in pupils’ daily activities. The increased connectivity and multifunctionality of urban green infrastructure through small, specialized green areas, such as SGAs, is an indicator of the fact that such areas can be used to ameliorate the deficit of green space in major urban areas.     

Spatial statistical analysis of the relationship between self-reported mental health during the COVID-19 lockdown and closeness to green infrastructure

The COVID-19 pandemic has produced alterations in the behaviour and psychological health of people, who have had to learn living under uncertain circumstances escaping their control. This situation has been aggravated in those countries applying strict home confinement rules to try bending their epidemic curve. This is the case of Spain, where the stringent lockdown period was extended over three months. This study aimed at proving a research hypothesis whereby living close to Green Infrastructure (GI) during the confinement period was beneficial for mental health. To this end, La Palma (Canary Islands) and Zaragoza (Peninsular Spain) were taken as case studies, since both locations distributed a questionnaire to address citizenry’s self-reported mental health under strict lockdown conditions. A spatial statistical analysis of the responses collected by these questionnaires revealed that variables such as stress, anger, medication use, alcohol consumption or visits to the doctor significantly decreased if citizens were close to GI, whereas people having very high expectations of enjoying the city after the confinement were positively correlated to proximity of green areas. Although these outcomes are limited by the inferential capacity of correlation analysis, they point out to a sense of relief derived from having visual contact with vegetated landscapes and feeling stimulated about using them for recreation, aesthetical or sporting purposes. The joint consideration of these psychological gains with the social and environmental benefits provided by GI emphasizes the importance of approaching urban regeneration through the design and implementation of interconnected green spaces.     

A spatially-explicit method to assess the dry deposition of air pollution by urban forests in the city of Florence,Italy

Urban forests (UF) provide a range of important ecosystem services (ES) for human well-being. Relevant ES delivered by UF include urban temperature regulation, runoff mitigation, noise reduction, recreation, and air purification. In this study the potential of air pollution removal by UF in the city of Florence (Italy) was investigated. Two main air pollutants were considered – particulate matter (PM₁₀) and tropospheric ozone (O₃) – with the aim of providing a methodological framework for mapping air pollutant removal by UF and assessing the percent removal of air pollutant.The distribution of UF was mapped by high spatial resolution remote sensing data and classified into seven forest categories. The Leaf Area Index (LAI) was estimated spatially using a regression model between in-field LAI survey and Airborne Laser Scanning data and it was found to be in good linear agreement with estimates from ground-based measurements (R² = 0.88 and RMSE% = 11%). We applied pollution deposition equations by using pollution concentrations measured at urban monitoring stations and then estimated the pollutant removal potential of the UF: annual O₃ and PM₁₀ removal accounted for 77.9 t and 171.3 t, respectively. O₃ and PM₁₀ removal rates by evergreen broadleaves (16.1 and 27.3 g/m²), conifers (10.9 and 28.5 g/m²), and mixed evergreen species (15.8 and 31.7 g/m²) were higher than by deciduous broadleaf stands (4.1 and 10 g/m²). However, deciduous forests exhibited the largest total removal due to the high percentage of tree cover within the city. The present study confirms that UF play an important role in air purification in Mediterranean cities as they can remove monthly up to 5% of O₃ and 13% of PM₁₀.     

The usage,constraints and preferences of green space at disadvantage neighborhood: A review of empirical evidence

Neighborhood green space is closely related to the lives of every city dweller. However, some evidence showed that residents in disadvantaged neighborhoods do not fully use the green space due to quality, safety, and distance issues. Therefore, it is essential to understand how disadvantaged groups interact and use green space in these communities. However, there is still a lack of comprehensive evaluation. This research systematically sorts out the relevant literature and collects various attributes of the use, constraints, and preferences of the residents of disadvantaged neighborhoods on the green space through a systematic review method from the perspective of social ecology. Through a literature review of 4 databases (Science Direct, Scopus, web of science, and CNKI), 42 articles (N = 42) were finally included. This article concerns peer-reviewed papers published between 2008 and 2021. The research results showed that residents of disadvantaged communities' use of nearby green space are affected by personal, social, physical, and other attributes. Finally, a conceptual framework for the use, constraints, and preferences of disadvantaged neighborhood green space is proposed to help planners and designers design and improve community green space more effectively and ultimately achieve a harmonious living environment that meets various needs.     

Public perceptions and attitudes toward green infrastructure on buildings: The case of the metropolitan area of Athens,Greece

As the impact of green space shrinkage in urban centers becomes obvious, local and regional authorities must adopt environmental planning policies that can help create new green areas to ensure a good quality of life for citizens, along with the rehabilitation of the natural environment. One approach is the promotion of green infrastructure on buildings, including multi-dwelling apartment buildings. In order to effectively promote green infrastructure on buildings, it is essential to comprehend public attitudes toward green infrastructure, so that suitable and effective strategies can be implemented by policy makers. In this study, eight hundred respondents were asked to provide their views on green infrastructure on buildings, on construction that should take place on blocks of apartments in order to accommodate green infrastructure and on the related benefits that may arise from creating green spaces on buildings. A structured questionnaire and stratified sampling were used for the interviews, which were conducted with apartment owners in two regional units of Athens. The results showed that most citizens are willing to proceed with the installation of a green roof, trellis or vertical garden, in order to improve the aesthetics and functionality of the building they live in. Most of the respondents are not familiar with the energy savings that may occur from the installation of a green roof, vertical trellis or garden and wish for a subsidy from the state in order to implement green building solutions. To conclude, the participants in our study are not environmentally aware, since they are not interested in energy conservation but only about the aesthetics of their building; furthermore, they expect to receive financial support from the state in order to make any changes to their home.     

Making trees visible: A GIS method and tool for modelling visibility in the valuation of urban trees

Tree visibility is a key determinant of cultural ecosystem services of urban trees. This paper develops a flexible, efficient and easy-to-use GIS method for modelling individual tree visibility to support tree valuation. The method is implemented as a GRASS GIS AddOn tool called v.viewshed.impact, making it available to a broad spectrum of users and purposes. Thanks to empirically validated underlying algorithms and parallel processing, the method is accurate and fast in analysing high-resolution datasets and large numbers of trees. We demonstrate the method in two use cases in Oslo, Norway, showing that it provides an alternative to field-based assessment of visibility indicators in tree valuation methods and facilitates the inclusion of complex visibility indicators not possible to assess in the field. We argue that the method could also be used for tree management and planning, urban ecosystem accounting and neighbour conflict resolution related to trees.     

Barriers to the effective planning and management of residential encroachment within urban forest edges: A Southern Ontario,Canada case study

Studies document degradation and loss of publicly owned urban woodland area following adjacent residential development due to residential encroachment. Residential encroachment is the negative impacts of housing land uses within both rural and urban green infrastructure networks. Prevailing planning, design and management approaches in Southern Ontario municipalities in Canada indicate planning and management tools have been developed to remove and impede encroachment impacts; however, many are infrequently implemented. This lack of implementation contributes to a high prevalence and spatial area of encroachment within Southern Ontario municipal woodland edges with adjacent housing. Long interviews were conducted with the planners, landscape architects, woodland managers and bylaw enforcement staff of six Southern Ontario municipalities to determine the barriers to implementation of municipal encroachment tools. Results indicate key barriers to policy implementation that reflect a lack of awareness of, and priority placed on addressing, residential encroachment impacts, and impacts following the point of development in general. Barriers include: (1) insufficient community and municipal access to information regarding residential encroachment and their significance relative to other development impacts; (2) lack of clarity of goals by municipalities and between departments; (3) insufficient municipal leadership and commitment to limiting encroachment; (4) lack of sufficient means within municipal departments to prevent and address encroachment; and (5) ineffectual dynamics of enforcement. Recommendations for overcoming barriers to the development and implementation of effective approaches for addressing encroachment are provided.     

Influence of tree crown characteristics on the local PM10 distribution inside an urban street canyon in Antwerp (Belgium): A model and experimental approach

Apart from influencing the amount of leaf-deposited particles, tree crown morphology will influence the local distribution of atmospheric particles. Nevertheless, tree crowns are often represented very rudimentary in three-dimensional air quality models. Therefore, the influence of tree crown representation on the local ambient PM₁₀ concentration and resulting leaf-deposited PM₁₀ mass was evaluated, using the three-dimensional computational fluid dynamics (CFD) model ENVI-met^® and ground-based LiDAR imaging. The modelled leaf-deposited PM₁₀ mass was compared to gravimetric results within three different particle size fractions (0.2–3, 3–10 and >10 μm), obtained at 20 locations within the tree crown. Modelling of the LiDAR-derived tree crown resulted in altered atmospheric PM₁₀ concentrations in the vicinity of the tree crown. Although this model study was limited to a single tree and model configuration, our results demonstrate that improving tree crown characteristics (shape, dimensions and LAD) affects the resulting local PM₁₀ distribution in ENVI-met. An accurate tree crown representation seems, therefore, of great importance when aiming at modelling the local PM distribution.