Urban Green Infrastructure Planning Research Articles

Developing an integrative management plan for urban and peri-urban forests: A case study of Ljubljana, Slovenia

Many cities worldwide have adopted management strategies for urban forests, typically focusing on forest parks, street trees and park trees. However, planning that concentrates on natural urban forest areas remains scarce. This study introduces an advanced planning framework for the integrative management of natural urban forests and applies it to Ljubljana's urban forests (2151 ha). The framework consists of an initiation phase and a six-step planning procedure. Through a comprehensive process lasting 20 months, with strong stakeholder involvement and political support, we developed a strategic plan for Ljubljana’s entire urban forest area and an operational plan for a specific block within this area. The approach employs the integrative management of forest stands within or near the city, incorporating harmonised activities in silviculture, recreation, protection, harvesting and communication. This planning method aims to bridge the gap between traditional forest management planning and urban green infrastructure planning.

Contextual and socio-economic factors affected urban dwellers experiences of and vulnerability to ecosystem disservices

Peoples’ experiences of Ecosystem Disservices (EDS) are influenced by socio-economic and environmental characteristics, and this needs better understanding for informed planning and management of urban green infrastructure. The paper investigated the understudied area of how socio-economic and environmental factors influence people's experiences of EDS in urban green spaces, in four towns in South Africa. Employing a questionnaire survey, in 303 randomly selected households in three neighborhoods of different economic standing, alongside statistical analysis provided quantitative data on experiences and vulnerability to EDS. A list of reported EDS was compiled and the number of EDS/respondent was compared between towns, neighborhoods and places of experience, using Kruskal-Wallis test and nested ANOVAs. Respondents’ vulnerability to EDS was assessed by analyzing the magnitudes of experience and coping abilities. The influences of socio-economic and environmental characteristics on experiences of and vulnerability to EDS were assessed using PCAs. Twenty-three EDS were reported in total, with the highest numbers recorded in affluent areas and the lowest in the poorest areas. Irrespective of town and neighborhood, the reported EDS were mainly experienced in domestic gardens and surrounding streets. Consequently, only one EDS seems of high concern, while the others are of lower concern or well manageable by the respondents. Significant influences of socio-economic (education and income levels, source of income, upbringing, frequency of visits to green spaces (GS), length of residence in neighborhoods) and environmental (environmental worldview, garden ownership, membership to environmental NGO) characteristics were observed on the experiences and vulnerability to EDS. Therefore, such variations in and influences on peoples’ experiences and vulnerability to EDS should be considered for sustainable management of urban GS. Also, the creation of GS should be accompanied by actions to improve people relationships to nature as well as to ensure their maintenance and security, particularly public GS and commonages.

Scalar transport after a high-resolution solitary fractal tree based on large-eddy simulation: Implication to urban green infrastructure

Scalar transport is one of the most concerned issues in the urban environment (e.g., pollutants, pollens, and aeolian transport). Vegetations are commonly regarded as scalar-moderation structures in urban areas by influencing airflows, avoiding aeolian erosion and pollution. The morphological multi-scale branch structures of the single tree were usually neglected in previous studies, which, however, can lead to highly inhomogeneous wake. The turbulence generation through the multi-scale branches is not yet clear. The corresponding spatial details of scalar distribution and its mechanism need to be further examined. In this study, the wake after a single fractal tree is investigated using the large-eddy simulation (LES). The spatial characteristics of the wakes are illustrated, indicating susceptible zones in the canopy, first-generation levels of branches, and recirculation regions. Higher-order moments signify the rare, extreme events with strong upward acceleration, removing air masses likely to occur at the canopy shear layer within 3h downstream where h is the characteristic tree height. The quadrant analysis elucidates the scalar transport potential. The scalar distribution and its transport mechanism are visualized, showing dilution and accumulation by the streamwise and vertical velocities. Involving the multi-scale geometries of the tree can provide guidance for urban green infrastructure (UGI) planning, advancing environmental and sustainability development.

Green Infrastructure Fluctuations in Urban Agglomeration of Shanxi Province, China: Implications for Controlling Ecological Crises

The rapid urbanization process means that even moderate-sized cities can quickly become part of larger urban agglomerations, creating new urban zones. Urban Green Infrastructure (UGI) plays a crucial role in these clusters, acting as precious green spaces essential for maintaining ecological safety. This study combines fluctuation analysis based on Morphological Spatial Pattern with traditional landscape pattern analysis, comprehensively addressing the evolution of UGI in terms of quantity, characteristics, and morphology. We selected the Taiyuan-Jinzhong agglomeration as our study area, which is currently in an agglomeration process. The results demonstrated the critical role of surrounding mountains as natural ecological barrier zones. During urban agglomeration, management strategies focused on large-scale afforestation to ensure the quantity of UGI. However, this approach also led to a more clustered landscape with reduced connectivity. Additionally, linear or small-scale UGI types such as branch and islet have seen reductions over the past decade. Changes in internal morphological and complex fluctuations within UGI can harm the formation of ecological networks and potentially negatively affect biodiversity and ecological safety. The research highlights how ecological protection and urban planning policies can influence UGI fluctuations. Therefore, urban managers should not just concentrate on maintaining the quantity of UGI, but also give consideration to changes in its internal features and morphology. Before cities further agglomerate into larger urban clusters, it is crucial to address deficiencies in UGI, continuously improving type configurations and functional structures at the landscape scale. Through strategic planning of UGI, cities can mitigate ecological risks and foster sustainable urban development.

Mapping pollen allergenicity from urban trees in Valencia: A tool for green infrastructure planning

Urban trees provide many benefits to citizens but also have associated disservices such as pollen allergenicity. Pollen allergies affect 40% of the European population, a problem that will be exacerbated with climate change by lengthening the pollen season. The allergenic characteristics of the urban trees and urban parks of the city of Valencia (Spain) have been studied. The Value of Potential Allergenicity (VPA) was calculated for all species. The most abundant allergenic trees with a very high VPA were the cypresses, followed by Platanus x hispanica and species of genera Morus, Acer and Fraxinus, with a high VPA. On the contrary, Citrus x aurantium, Melia azedarach, Washingtonia spp., Brachychiton spp. and Jacaranda mimosifolia were among the most abundant low allergenic trees. VPA was mapped for the city and a hot spot analysis was applied to identify areas of clustering of high and low VPA values. This geostatistical analysis provides a comprehensive representation of the VPA patterns which is very useful for urban green infrastructure planning. The Index of Urban Green Zone Allergenicity (IUGZA) was calculated for the main parks of the city. The subtropical and tropical flora component included many entomophilous species and the lowest share of high and very high allergenic trees in comparison with the Mediterranean and Temperate components. Overall, a diversification of tree species avoiding clusters of high VPA trees, and the prioritization of species with low VPA are good strategies to minimize allergy-related impacts of urban trees on human health.

Landscape and soundscape quality promote stress recovery in nearby urban nature: A multisensory field experiment

Cities have different benefits and risks, but are often stressful environments to live in. Everyday contact with nearby nature can be a crucial way to alleviate stress and increase the well-being of citizens. However, there is still limited evidence on how nature-health benefits vary according to the type and quality of natural environments. This study integrated multiple landscape and soundscape objective and perceived assessments to examine stress recovery in different types of neighbourhood nature. We used a field randomised experiment (n=45) to analyse effects of various random and fixed factors on restoration including: environmental conditions (e.g. temperature, wind, air quality), personal characteristics (e.g. age, gender, perceived health, nature connectedness), presence of other people and environmental quality (e.g. Perceived Environmental Aesthetic Qualities Scale and Perceived Sound Affective Quality scale). We found that physiological and psychological restoration is significantly greater in sites with higher visual (% visual natural elements) and acoustic (Normalized Difference Soundscape Index (NDSI)) naturalness i.e. the beach and forest, compared to the urban park (control site). Perceived landscape and soundscape quality were strongly associated with stress recovery, and these results were more pronounced for the soundscape. This highlights that soundscape quality assessments deserve more systematic attention in urban green infrastructure research and planning. Finally, we found important early evidence of reduction in Electrodermal activity (EDA) only within 3 minutes of nature exposure especially in the forest.

Integrating landscape ecology in urban green infrastructure planning: A multi-scale approach for sustainable development

In response to the growing global recognition of the need to achieve sustainable development, significant efforts are underway to actively integrate nature into the urban environment by implementing green infrastructure. However, due to rapid urban growth, there is a need for novel approaches that integrate ecological knowledge and methods into urban green infrastructure design and development. Traditionally, the planning of green infrastructures in large metropolises has primarily approached from a unique city scale perspective. Here, we advocate for a multi-scale approach, encompassing both spatial and temporal dimensions. This is because by considering space, time, and scale, it is possible to identify relevant elements and constraints at each level and integrate them in an overall solution.This paper combines methodologies and concepts derived from the fundamentals of landscape ecology and proposes their integration into the planning of functional green infrastructures within an urban context. We explore distinct strategies to integrate nature into large cities through three perspectives: urbanism, landscaping, and ecology. The approach used assumes the necessity of a multi-scale framework to establish an integrated and sustainable green system, exemplified by the case study of the city of Madrid (Spain).Considerable progress has been made in the planning of a green belt within Madrid city. However, this initiative has focused primarily on a large-scale, leading to a minimal impact on the city core. To address this limitation, the proposed solution employs a multi-scale approach. By developing a connected network, we aim to provide a comprehensive plan for the integration of green infrastructure throughout the whole urban area.

Assessing urban green infrastructure: A simple and practical measure of its spatial distribution equity and a comprehensive evaluation

Urban green infrastructure (UGI) that provides diverse ecosystem services are crucial components of a city. Achieving appropriate density and equitable distribution of UGI is highly significant for urban planning to ensure sustainable and high-quality development. However, there is still a lack of an applied method for effectively measuring spatial equity of UGI in cities with multiple scales, which impairs the ability to regularly monitor it. Furthermore, the extent to which UGI should be implemented in urban planning in China is still uncertain. In this study, a “Structure-Function-Zoning“ analysis framework for the spatial pattern of UGI is proposed. A monitoring index system in terms of the structure and functions of UGI is first established. Then, an approach for measurement of spatial distribution equity of UGI is developed based on a spatial zoning strategy along the urban expansion axis. And a weighted index is proposed for comprehensive evaluation of UGI pattern. Using three Chinese cities (i.e., Beijing, Tianjin, Shijiazhuang) as examples, our research shows that the UGI pattern of Tianjin is distributed more balanced from urban center to suburb among the cities and Shijiazhuang shows relatively poor spatial equity of UGI. In terms of comprehensive evaluation of UGI pattern, Beijing and Tianjin are both rated as “moderate” while Beijing was slightly better than Tianjin, and Shijiazhuang was rated as “relatively poor”. The proposed analysis framework is designed to access the structure and function of UGI in a way that can be spatially differentiated, easily described, and clearly compared for cities of different sizes. More broadly, the comprehensive index adopted in the study can be regarded as a simple and practical tool to perform regular monitoring and provide early warning for UGI planning in urban renewal process.

Heterogeneous effects of the availability and spatial configuration of urban green spaces on their cooling effects in China

The impacts of the availability and spatial configuration of urban green spaces (UGS) on their cooling effects can vary with background climate conditions. However, large-scale studies that assess the potential heterogeneous relationships of UGS availability and spatial configuration with urban thermal environment are still lacking. In this study, we investigated the impacts of UGS availability and spatial configuration on urban land surface temperature (LST) taking 306 cities in China as a case study covering a multi-biome-scale. We first calculated the availability of surrounding UGS for urban built-up pixels in each city using a distance-weighted approach, and its spatial configuration was quantified through the Gini coefficient. Then, we employed various regression models to explore how the impacts of UGS availability and the Gini coefficient on LST varies across different LST quantiles and between day- and nighttime. The results revealed that UGS availability was negatively associated with both daytime and nighttime LST, while the Gini coefficient showed a positive impact solely on daytime LST, indicating that an adequate and equally distributed UGS contributes to lower environmental temperatures during the daytime. Furthermore, the impact of UGS availability on LST decreased during both day- and nighttime with increased background LST quantiles. Whereas the impact of the Gini coefficient increased only with daytime LST quantile levels, with its effect remaining almost insignificant during the night. Our findings provide new insights into the impacts of UGS on urban thermal environment, offering significant implications for urban green infrastructure planning aiming at lowering the urban heat island.

Predicting context-sensitive urban green space quality to support urban green infrastructure planning

Urban green spaces (UGSs) support human health and well-being in diverse ways. In addition to their availability and accessibility, also the quality of UGSs is relevant for understanding human-environment interactions between urban populations and their local UGS. However, data on UGS quality are rarely available with the geographic coverage required for spatial decision making and urban green infrastructure (UGI) planning and management.This study uses data from a large-scale public participation GIS (PPGIS) survey to predict perceived UGS quality across the city of Espoo, Finland. The respondents (n 3,132) mapped over 8,500 frequently visited sites situated in UGSs. Generalized linear mixed models were used to study associations between the perceived place quality of the respondent-mapped sites and diverse objectively measured UGS characteristics. The presence of blue elements, high forest biodiversity, level of UGS maintenance, and low daytime noise exposure contributed to positive perceptions of UGS quality, while daytime noise exposure and decreasing UGS size were associated with negative perceptions.The model was extrapolated spatially to predict perceived UGS quality across the entire city, revealing local differences in the accessibility of high-quality UGS. The results exemplify how both UGS quantity and quality are relevant for understanding the mechanisms leading to UGS visitation and the health and well-being benefits gained from UGS use and exposure. Moreover, the study demonstrates how UGS characteristics valued by the local population may be identified to support local UGI planning and management.

Identifying the optimization potential for urban GI by linking supply and demand of ecosystem services under multi-scenarios : a case study of Tianjin, China

Quantitative research on the supply and demand of urban green infrastructure (GI) ecosystem services (ES) can play a crucial role in supporting ecological governance, which is vital for enhancing the health and well-being of residents and promoting sustainable development. However, current supply and demand studies often fail to consider the complexity and diversity of local climates and economic status, leading to suboptimal outcomes in urban greening programs. Therefore, there is an urgent need to incorporate the diversity and variability of demand for ES in decision-making processes for urban GI planning. To address this issue, this study proposes a multi-development scenario-based supply and demand modelling framework that measures the supply and demand of ES. By using the central city of Tianjin, China, as a case study, the resulting GI construction potential zoning and optimization strategies are determined to achieve the multiple environmental-social-economic benefits of GI. The results show that the supply and demand levels of GI in the study area are significantly spatially heterogeneous, with the demand levels of GI varying considerably under different development scenarios. Furthermore, the demand for GI is highest under the ecological priority scenario. Based on the relationship between the supply and demand of ES, the study area is classified into four zones, including a GI supply deficit zone, a supply surplus zone, a low-level balance zone, and a high-level balance zone. The area of each zone decreases in turn, indicating that the study area as a whole is in a state of mismatch between the supply and demand of ES. Finally, the study area is divided into seven GI construction potential zones based on the degree of scarcity and development orientation. The proposed planning scheme helps to achieve dynamic matching goals of ES supply and demand and provides valuable insights for policymakers to coordinate urban resources and promote sustainable development.

Evaluating the Capability of Woody Plants to Capture Atmospheric Heavy Metals in Budapest

Urban green infrastructure planning plays an important role in aspects of pollution reduction, such as heavy metal trapping. However, the reduction effects are both influenced by the different pollution conditions in each city and the species-specific interaction of trees and pollution. Herein, we investigated three common urban woody plants (Acer platanoides L., Fraxinus excelsior L. Westhof’s Glorie, and Tilia tomentosa Moench) in Budapest to compare their heavy metal trapping abilities from the airborne in leaf dust deposits and leaves. All samples were deconstructed by a wet digestion method. Four high traffic-related heavy metal elements (Zn, Cu, Pb, and Ni) were determined by using an atomic absorption spectrometer (AAS). The investigated results showed that the relevant concentration of all measured elements was constant in all species, namely Zn < Cu < Pb < Ni. Although the total heavy metal content in the dust deposit increased towards the end of one vegetation period, the highest percentage of total metal concentration was in the summer season as the particulate matter sources varied in each season. These indicate that woody plants are ideal candidates for pollution monitoring. All of the evaluated elements were loaded highest in the dust deposit of T. tomentosa during all sampling times, followed by A. platanoides, and the least in F. excelsior. A significant correlation between metal contents in the dust deposit and leaf was found in T. tomentosa (0.926 at a p<0.01 level). Therefore, we suggest T. tomentosa, which has better atmospheric trace element capturing capacity than A. platanoides and F. excelsior and thus it is a better option for pollution reduction in the urban area.

The public consultation is open: Insights from urban green infrastructure planning in Romania

Due to its potential to help mitigate current societal challenges and provide ecological, social, and economic benefits, urban green infrastructure (UGI) is an important investment for cities. However, its planning and implementation may be challenging due to the limited application of the conceptual foundations and the often-unknown character of the ways how the results of public consultations were integrated into the implemented UGI design. Using five Romanian urban areas as model system, we developed an evaluation protocol to assess 177 written comments submitted during the public consultation processes for 13 public UGI planning documents, along with the formal responses to these comments. Our results show critical comments towards the planning proposals (86.2 % of the comments) and a discussion of the shortcomings of the planning process (60.8 % of the comments). The analysis revealed that the UGI as it is developed and implemented currently in Romania has little public support as in 52.2 % of the comments none of UGI planning principles could be identified. Furthermore, we found a relatively low level of public comment consideration into the approved version of the planning documents as only 7.6 % of the comments were included, most of them being delegitimized by the responses of public officials/municipal administration. Thus, our results highlight that UGI consultation process is characterized by a lack of both genuine conceptual aspects and public participation substance.

Greening plans as (re)presentation of the city: Toward an inclusive and gender-sensitive approach to urban greenspaces

Cities around the world are increasingly expanding their sustainability agendas and adopting urban green and blue infrastructure planning as a strategy to become more resilient, healthy and sustainable. However, the development of urban greening governance often lacks a holistic vision that considers social inequities within the planning, implementation and management of green and blue spaces. Further, gender inequities have been a specific dimension particularly overlooked in urban greening planning, despite gender concerns gaining increasing political relevance in recent years. In this research, we assessed the extento to which social and gender equity are being considered in urban greening plans and projects at the local level. We chose Barcelona (Spain) as main case study due to its pioneering role in implementing crosscutting equity and gender policies at the municipal level. Building on document analysis and semi-structured interviews with key stakeholders, we examined how social justice and gender are understood and operationalized in practice, from the design phase to implementation and maintenance of greening projects. Our findings suggest a shift in the role of urban greening which evolved from an ornamental role to a multifunctional vision of greening and is recently incorporating equity and inclusivity concerns. We identified three action areas of inclusive, gender-sensitive urban green planning practices: first, the incorporation of inclusivity and care as guiding visible values to recognize multiple needs of city residents; second, urban design for different uses and perceptions of greenspaces, particularly in relation to accessibility and autonomy; and third, the awareness and expertise from municipal staff vis-à-vis the consideration of social and gender equity in green planning and participatory approaches. Finally, we provide practical examples of the strategies that the City of Barcelona is implementing in each area and discuss some challenges and limitations, including what we identify as ad hoc intersectional greening.

Modelling PM10 removal in three Italian coastal Metropolitan Cities along a latitudinal gradient

Air pollution is regarded as the largest environmental risk factor in Europe, and Particulate Matter (PM) is considered one of the most harmful pollutants. Among the Ecosystem Services (ESs) it provides, the Urban Green Infrastructure (UGI) is capable of capturing and adsorbing pollutants through removal mechanisms. As envisaged in the National Plan for Recovery and Resilience (PNRR), Italy has planned on investing about EUR 300 million of the Next Generation EU funds in urban reforestation programs that will target Italian Metropolitan Cities (MCs). Successful implementation of such interventions is underpinned by a thorough knowledge of the presence and distribution of existing vegetation and its capacity to deliver ESs. In the present study, we selected three Italian coastal MCs along a latitudinal gradient, namely Genoa, Bari, and Reggio Calabria, and assessed the regulating ES of PM10 removal by urban and peri-urban forests in both biophysical and monetary terms. In 2019, the total PM10 removal in the MCs of Genoa, Bari and Reggio Calabria amounted to 5,331, 363, and 4,248 Mg respectively, for a corresponding monetary value of EUR 536, 39, and 435 million. Our analyses were conducted on a seasonal basis and further aimed at investigating the role of functional diversity in ES provision. According to our findings, in all MCs the highest annual average PM10 removal efficiencies were exhibited by the evergreen broadleaves; deciduous broadleaves also displayed high efficiency values, despite being characterized by a marked seasonality caused by leaf abscission. Conifers proved less efficient, although our findings may indicate a good response to a condition of multi-stress. Maintaining a functionally-mixed species composition in the UGIs is desirable for guaranteeing the continuous provision of ESs throughout the year. In conclusion, our results provide useful insights to support the sustainable planning and management of UGIs, as envisaged by the United Nation's 2030 Agenda for Sustainable Development.

Stewardship and green infrastructure in England. Planning perspectives informed through an investigation of urban green infrastructure

The aim of this study is to explore the relationships and perspectives of stakeholders involved in the stewardship of ‘urban green infrastructure’ in England. We used stewardship of the urban forest network (trees and associated green space) as a focal point by referring to four meanings of ‘Stewardship’, i.e. Motivation, Ethic, Outcome and Action proposed by Peçanha Enqvist et al. (2018). We studied the perspectives of stakeholders through a multi-regional approach, in five English cities (Newcastle/Gateshead, Leeds, Sheffield, Coventry and Bristol), assessing their views expressed via questionnaire and analysing responses through NVivo. We found support for stewardship as a key aspect of urban green infrastructure planning, one that encourages ‘bottom up’ participation. In the specific area of urban forestry in England we propose that to ensure a co-stewardship role, planning professionals and citizens should work together at all levels to identify key roles and stewardship niches that are complementary.

Identification of priority areas for UGI optimisation under carbon neutrality targets: Perspectives from China

Carbon neutrality targets are a common objective for cities and regions worldwide, the achievement of which relies on the transformation of urban infrastructure. Urban green infrastructure (UGI) is the only resilient carbon sequestration subsystem within cities in the carbon cycle process; however, a straightforward and feasible evaluation system for guiding the regulation and planning decisions regarding UGI as a carbon sink has yet to emerge. Here, we simulated the net primary productivity (NPP) of vegetation in Wuhan in 2020 based on the Sentinel-2 improved CASA model and assessed the efficiency of UGI carbon sequestration by combining the biomass-carbon conversion coefficient and zonal statistical tool. Potential influencing variables were explored based on the P-S-R model. Then, the optimal parameter-based geodetector revealed the driving mechanism of spatial heterogeneity in the efficiency of the UGI carbon sequestration service supply in highly urbanized regions, based on which we developed the ‘Carbon Sequestration Enhancement Priority Index’ (CSEPI), a strategic planning tool for identifying priority areas in which to implement carbon sink-enhanced field intervention measures. For these ‘high-priority’ areas, further UGI partition management tools and partition optimisation strategies are proposed. Our study contributes to the scientific planning and management of UGI in the context of combating climate change and with limited national public investment.

Influence of perceived social benefits on motives for visiting urban green infrastructure spaces in small and medium-sized towns in Southeast Nigeria

Although the benefits of urban green infrastructure (UGI) in sustainable development are well established in the literature, the specific benefits with the most influence on why people visit or use UGI spaces are not well understood. This study investigated the influence of perceived social benefits on motives for visiting UGI spaces in small and medium-sized towns in Southeast Nigeria. A survey of 513 participants in four main towns of Ebonyi State, Southeast Nigeria was done. The data were analysed using the Mann-Whitney U and Kruskal-Wallis H tests, descriptive and categorical regression analyses. The findings showed that the main motives for visiting UGI spaces were for enjoying nature, fresh air, relaxing, and walking these were significantly different across the respondents' age, marital status, and location. The role of UGI in promoting human-nature interactions, enhancing life satisfaction, and social interactions were the top three social benefits identified. The three social benefits with the most significant influence on motives for visiting UGI were the role of UGI in promoting physical well-being, social relations, a sense of community, and life satisfaction. The study implies that understanding public motives for visiting/using GI spaces and their predictors is vital for effective policy-making, planning, and management of UGI.

"Public Perception of Urban Green Infrastructure Quality in Towns from Southeast Nigeria "

The extent to which green infrastructure contributes to the sustainability of the urban ecosystem is determined by several factors, including its availability in quantity and quality. However, in many urban areas in Nigeria, very little research has been done to deepen understanding of the quality of green infrastructure and its determinants. This research investigated the public perception of urban green infrastructure (UGI) quality and the factors that influenced this in four major towns in Ebonyi State, Southeast Nigeria. A survey of 513 participants was conducted with the data analysed using descriptive and categorical regression analyses, Mann-Whitney U, and Kruskal-Wallis H Tests. The results revealed that many of the participants have regular contact with UGI mainly for enjoying nature and fresh air, and preferred trees and water features. It was also observed that 66% of the respondents felt that the quality of green infrastructure in their locations was generally good but relatively higher where they work or do business than where they live. Differences in perception of UGI quality were due to their level of education, town of location, and type of neighbourhood environment. The regression analysis revealed that the respondents’ level of education, age, and marital status had the most significant influence on their perception of UGI quality. This study implies that for a better understanding of the public perception of UGI quality and effective planning and provision of UGI the factors identified in this research should be given adequate consideration by urban planners and managers.

Urban green infrastructure affects bird biodiversity in the coastal megalopolis region of Shenzhen city

Urban green infrastructure (UGI) is an important habitat for birds and acts a leading role in bird diversity conservation. However, the response of bird diversity to UGIs characteristics have not been well understood. Taking Shenzhen as an example, a dataset of bird records was compiled by several citizen science. We quantified the impact of environmental characteristics of UGI on bird diversity by the generalized additive model. Then, the clustering method was used to classify bird diversity bundles for identifying priorities of UGIs. The results showed that: (1) There are significant differences in urban gradients formed the spatial pattern of bird diversity. (2) There was mainly nonlinear relationship between the bird diversity and UGI environmental characteristic, with different response processes and thresholds. Area of UGI was critical for bird diversity, and an area of about 20 km2 plays a relatively large role. Moreover, migratory birds were more sensitive to the negative impact of the surroundings of UGI, such as impervious surfaces and nighttime light. (3) The cluster analysis indicates that UGIs with better eco-environment were conducive to maintaining bird diversity. This study could be helpful to provide guidelines for the implementation of UGI planning and management and bird diversity conservation.