Optimizing urban green space patterns to improve spatial equity using location-allocation model: A case study in Wuhan

Green space allocation aims to support the UNs sustainable development goals (SDGs) and to mitigate the conflicts between supply and demand. Previous studies have shown that the uneven distribution of populations and natural locations of green space results in environmental inequity. However, there is still a lack of knowledge on strategies for reducing mismatches of supply and demand by optimizing spatial patterns in highly dense cities. Developed urbanized areas are featured in fewer spaces for greening. In this study, we set three scenarios for coordinating the provision and demand of urban green spaces at a block scale. Taking the main city of Wuhan as an example, we apply the location-allocation model in order to identify potential sites for new green spaces. Then, the simulations of the three scenarios are used to depict various development strategies by evaluating the improvement of green equity. Our results show that the levels of green space accessibility are lower on the west side of the city center, while relatively higher on the east side, due to abundant natural resources. The Gini coefficient is 0.715, indicating unequal access for citizens to green space. Increasing green areas could enhance green equity, and the most effective way to allocate new increments is based on the accessibility. For developed cities, blocks with lower accessibility should be given priority when increasing green areas; doing so could offset the shortage of large green areas and reduce green inequity within daily walking distances. Optimal green space planning of small and functional parks near communities has the potential to meet higher recreational demands in densely populated areas.     

Health-related elements in green space branding in Hong Kong

A green city image of urban green spaces can provide positive benefits such as a stronger local identity, better socio-cultural ecosystem services, and ultimately the creation of a green city brand that attracts tourism and investment. This paper studies how urban green spaces can become a green brand that encompasses health-related elements. The health-related elements form part of the Green Brand Hexagon (GBH), as proposed in previous studies, and are tested with a sample of Hong Kong citizens (n = 301). The empirical results confirm the interrelation between these attributes and other GBH elements. The interrelation reveals a moderate association between the health-related elements and other green brand elements through regression model formulation. The findings suggest an extension of the health promotion value of the green spaces to the brand elements, focusing on the quality and the landscape aesthetic function of urban green spaces. While the effort of the public sector is highly recognized by the citizens, there should be an opportunity to thematize and brand the green city attributes to the public so that some of the problems of environmental gentrification and socio-environmental disconnection can be alleviated.     

The effect of spontaneous wild vegetation on landscape preferences in urban green spaces

The use of spontaneous wild vegetation (SWV) in the plans for urban greening in many cities is beginning to be discussed. However, little is known about how it is perceived and valued by citizens. The aim of this study was to determine the effect of SWV on landscape preferences. An online questionnaire was designed and given to a sample of 708 people in Latin America. The results show that they prefer more formal green spaces to those dominated by SWV. Once informed of the benefits that SWV brings to the city, preferences change, with wild vegetation spaces being more appreciated than formal ones. However, this pattern of preferences changes after 30 days. Preferences return to their initial point, with formal green spaces being appreciated again over wild spaces. The analyses show the importance of environmental education in urban greening strategies to communicate clearly, repeatedly and participatively the benefits of using SWV in public green spaces.     

Multiple ecosystem services of informal green spaces: A literature review

Informal green spaces (IGS) such as overgrown vacant lots and urban brownfields constitute a considerable amount of green resources in the city. Given that the increasingly competitive land use of the urban area, enhancing the potential ecosystem services (ES) of IGS through design and management practices is of critical importance. This literature review paper provides an overview of ES delivered by urban IGS: What types of IGS have been discussed? Which ES have been identified in IGS, what interrelationships among different types of ES have been identified, and how can the potential of IGS be enhanced by urban design practices? 112 scientific papers were analyzed for their 1) IGS terms applied, 2) ES studied, 3) current or potential ES discussed, 4) ES trade-offs, and 5) ES assessment methods. Through the review, we found that although different types of ES have been identified in IGS, most studies did not consider ES synergies and trade-offs. The few studies assessing trade-offs of ES in IGS mostly focused on large-scale IGS such as urban brownfields rather than on small-scale IGS such as vacant lands/lots. The literature review highlights two knowledge gaps for future research: the first one is to explore the design and management knowledge that integrate multiple ES in small-scale IGS based on the assessment of potential ES trade-offs and synergies; the second one is to develop the spatial assessment of ES trade-offs and synergies, which is the key to envision design and management interventions that optimize the benefits of IGS. The literature review promotes the acknowledgement of the term IGS through highlighting their value in ES provisioning and further outlines future research directions on small-scale IGS such as vacant lands/lots and patches of spontaneous vegetation.     

Towards a greening city: How does regional cooperation promote urban green space in the Guangdong-Hong Kong-Macau Greater Bay Area?

Promoting Urban Green Space (UGS) is one of the major requests of green cities for urban planners and local officials, and it is linked to myriad environmental and social benefits. However, scant literature has positioned the UGS into the background of fast regionalisation to unravel their relationships and mechanisms. This study delves into the impact and mechanisms of regional cooperation upon the provision of UGS in the Guangdong-Hong Kong-Macau Greater Bay Area (GBA), a dynamic city-region in southern China. Through social network analysis, panel data analysis, documentary review (analysis), and in-depth interviews, this study found that overall, regional cooperation has positive impacts on UGS provision in the GBA in the spheres of economic, social, institutional, and environmental affairs. We argued that economic cooperation encroaches on UGS by fostering infrastructure and economic zones; it also upgrades the industrial sectors and intensifies land use to positively affect UGS provision. Social cooperation reinforces population influx yet fosters social cohesion, sustainable lifestyles, and green economics to support the delivery of UGS policies. Environmental cooperation among local officials facilitates the implementation of urban greening projects, and institutional cooperation is conducive to urban governance in spatial greening planning. For the local government, the focal point for pursuing the green city vision is collaborative actions across the economic, social, environmental, and institutional spheres.     

Challenges of urban green space management in the face of using inadequate data

Effective urban planning, and urban green space management in particular, require proper data on urban green spaces. The potential of urban green spaces to provide benefits to urban inhabitants (ecosystem services) depends on whether they are managed as a comprehensive system of urban green infrastructure, or as isolated islands falling under the responsibility of different stakeholders. Meanwhile, different urban green space datasets are based on different definitions, data sources, sampling techniques, time periods and scales, which poses important challenges to urban green infrastructure planning, management and research. Using the case study of Lodz, the third largest city in Poland, and an additional analysis of 17 other Polish cities, we compare data from five publicly available sources: 1) public statistics, 2) the national land surveying agency, 3) satellite imagery (Landsat data), 4) the Urban Atlas, 5) the Open Street Map. The results reveal large differences in the total amount of urban green spaces in the cities as depicted in different datasets. In Lodz, the narrowly interpreted public statistics data, which are aspatial, suggest that green spaces account for only 12.8% of city area, while the most comprehensive dataset from the national land surveying agency reveals the figure of 61.2%. The former dataset, which excludes many types of green spaces (such as arable land, private and informal green spaces), is still the most commonly used. The analysis of the 17 other cities confirms the same pattern. This results in broader institutional failures related to urban green infrastructure planning, management, and research, including a lack of awareness of green space quality (e.g. connectivity) and benefits (ecosystem services), and the related political disregard for urban green spaces. Our comparison suggests that a better understanding of green space data sources is necessary in urban planning, and especially when planning urban green infrastructure.     

Biodiversity in sacred urban spaces of Bengaluru,India

Urban green spaces provide critical social and ecological support for cities, but we know little about their diversity and composition in cities of the Global South. This is especially true of lesser known urban spaces such as sacred sites, which are of important cultural and biodiversity significance. We examine tree diversity and composition in sacred sites in Bengaluru, one of India’s fastest growing cities. We recorded 5504 trees from 93 species across 62 temples, churches, and Hindu, Christian and Muslim cemeteries in central areas of Bengaluru. Over half (52%) of the tree species were of native origin, a much higher proportion when compared to other green spaces in the city such as parks. Tree density in sacred sites was much higher than that in parks and informal settlements in Bengaluru. Temples and Hindu cemeteries contained the highest proportion of native species, with large numbers of Ficus benghalensis, a keystone sacred species. Trees in sacred spaces provide an important buffer against urban environmental stress in Indian cities, and serve as refuges for urban wildlife and biodiversity. We need greater information on these lesser known, but culturally significant alternate spaces. They play an important, though ignored role in the environmental sustainability of rapidly growing cities in the Global South.     

A GIS-based mapping methodology of urban green roof ecosystem services applied to a Central European city

Green roofs provide a number of different urban ecosystem services (UESS), e.g. regulation of microclimate, support of air quality improvement, or stormwater retention. To estimate the spatial variation of green roof UESS across an urban area, a GIS-based mapping and spatial analysis methodology was established and applied to the city of Braunschweig, Germany. Based on the analysis of available geodata, in a first step, a quantity of 14,138 rooftops in the study area (14% of all buildings) was found to be generally suitable for greening. This resulted in a green roof area of 3 km². Based on criteria such as roof slope and minimum roof size, nearly two-thirds of these buildings (8596 buildings, 8.6% of total number of buildings) were categorised ‘appropriate’ for greening and subject to green roof UESS analysis.The spatial distribution of green roof UESS was estimated based on the categories thermal urban climate, air quality, stormwater retention and biodiversity. Due to their potential benefits in the four UESS categories an overall assessment resulted in a number of 867 roofs (0.9% of total number of buildings) categorised as ‘high benefit’ from rooftop greening. Another 3550 buildings (3.5%) and 4179 buildings (4.2%) were defined as ‘moderate benefit’ and ‘low benefit’, respectively. The inner city area of Braunschweig appears as a hot-spot of green roof UESS, i.e. higher percentage of ‘high benefit’ green roofs in comparison to residential areas. The proposed method is a simple but straightforward approach to analyse urban green roof UESS and their spatial distribution across a city but it is sensitive to the quality of the available input geodata.     

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.     

Perceptions of parks and urban derelict land by landscape planners and residents

As urban green spaces are important for residential satisfaction, human preferences are a key criterion in their design. However, preferences may vary between landscape planners and residents, which may result in differences between residents’ demands and the actual design. With urban derelict land becoming an important part of the urban green infrastructure, information about the perception and acceptance by residents compared to formal urban parks is important for their planning and design. It was thus examined how different types of urban green spaces are perceived by landscape planners and residents. Criteria for the classification of green spaces used by both participant groups were compared, as were the criteria that influenced preference.Participants sorted and rated photographs of parks and urban derelict land in two different tasks. Hierarchical cluster analyses and multidimensional scaling analyses were used to characterize the participants’ perceptual space. By conducting multiple regression analyses the resulting perceptual dimensions were related to preference.The identified perceptual criteria used to distinguish green spaces were degree of canopy closure, artificiality vs. naturalness, prospect, physical accessibility, and beauty. For residents, the degree of canopy closure was the most important criterion for classification; for landscape planners, it was artificiality. Preferences varied between groups: whereas landscape planners preferred rather natural areas with low accessibility and high species richness, the residents showed a greater preference for formal parks.As a practical implication, the study suggests that residents generally accept urban derelict land as recreational areas if a minimum of maintenance and accessibility is provided. When designing green spaces, landscape planners may consider these differences in their preferences compared to residents.     

Supplying urban ecosystem services through multifunctional green infrastructure in the United States

This paper summarizes a strategy for supplying ecosystem services in urban areas through a participatory planning process targeting multifunctional green infrastructure. We draw from the literature on landscape multifunctionality, which has primarily been applied to agricultural settings, and propose opportunities to develop urban green infrastructure that could contribute to the sustainable social and ecological health of the city. Thinking in terms of system resilience, strategies might focus on the potential for green infrastructure to allow for adaptation and even transformation in the face of future challenges such as climate change, food insecurity, and limited resources. Because planning for multiple functions can be difficult when many diverse stakeholders are involved, we explored decision support tools that could be applied to green infrastructure planning in the early stages, to engage the public and encourage action toward implementing a preferred solution. Several specific ecosystem services that could be relevant for evaluating current and future urban green spaces include: plant biodiversity, food production, microclimate control, soil infiltration, carbon sequestration, visual quality, recreation, and social capital. Integrating such ecosystem services into small-scale greening projects could allow for creativity and local empowerment that would inspire broader transformation of green infrastructure at the city level. Those cities committing to such an approach by supporting greening projects are likely to benefit in the long run through the value of ecosystem services for urban residents and the broader public.     

土壤质量对绿化植物影响综合评价

土壤作为植物生命活动的重要场所,为园林植物的正常生理活动提供所需的养分,低劣的园林土壤质量将极大地制约园林植物的生长。本文以西安市三环绿化带为例,对绿化用地进行了土壤质量对绿化植物影响综合评价,希望找出绿化植物长势衰弱的原因,为西安市园林土壤质量管理政策的制定提供科学依据。     

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.     

Knoxville’s urban wilderness: Moving toward sustainable multifunctional management

The Knoxville Urban Wilderness (KUW) in Eastern Tennessee is part of a larger global trend of acquiring vacant lands within urban landscapes for their natural habitat and recreation value. At 688 ha, the KUW is one of the largest urban wilderness areas in the United States, consisting of loosely-connected land parcels with multiple stakeholders including state, county, and city governments and private foundations. Here we use the KUW as a case study to address critical questions of management that arise for most urban wilderness projects globally: What should these areas be managed for, and how should they be managed? How can multiple stakeholders be efficiently organized to pool their resources most effectively. The KUW is currently used mainly for recreation and its potential for biodiversity conservation and education and ecosystem services is largely unutilized. As a way to promote and manage this unused potential, we began the first ecological inventory, compiling existing data and conducting biodiversity and invasive plant surveys with citizen scientists. We found that the KUW harbors a significant number of plant (250) and bird (193) species, with many other taxa also identified. We also found widespread infestation of invasive plants for which we provide management suggestions. A preliminary visitor survey shows that most visitors (about two-thirds) are from the immediate vicinity, mainly for walking (74.4%) or biking (19.9%). The vast majority (93.7%) of visitors do not want more vegetation management or removal and 98.3% of visitors would like to see the KUW expanded in area.     

Green space branding in Denmark in an era of neoliberal governance

City place branding, an entrepreneurial urban development scheme, aims to differentiate cities from their national and international competitors based on strengths and competitive advantage. One such strength is quality urban green space which has been shown to make cities more attractive and liveable places, drawing people and investments to urban centres. Applying a place branding approach, this paper presents the results of a survey of Danish municipalities and their place branding in terms of crafting green city, or environmentally sustainable, profiles. Based on survey responses from both municipal green space and communication staff, an overview is presented of the status of ‘green’ municipal place branding, with emphasis on branding through green spaces such as parks. Findings show that green concepts such as environmentally sustainable policies as well as biophysical assets such as green spaces are not in focus in municipal place branding campaigns. Moreover, survey results demonstrate that creative professionals and local citizens are the main focus of those municipalities that are branding. There is great potential to emphasize green spaces in municipal placing branding campaigns building on partnerships with the private sector and citizen volunteers.     

Biological potential in cities: An estimate from Melbourne

Despite the many benefits of vegetation in urban settings, inner-city areas often are sparsely vegetated or devoid of plants. This suggests substantial opportunity for improving provision of ecosystem services in densely populated areas, through retrofitting of urban environments with plants. This paper introduces the concept of ‘biological potential’ – the pragmatic potential for urban areas to be retrofitted with suitable green infrastructure.This paper demonstrates a method for making a quantitative, spatially explicit estimate of the biological potential of walls in the CBD of Melbourne, Australia. The results of this study represent an estimate of how much wall space could be home to green façade plants (i.e. creepers and climbers). The methodology is also spatially explicit – it estimates where the best locations in the city are for this kind of greening, recognising that not all walls have suitable physical characteristics or local microclimates. Employing a combination of GIS and microclimatic modelling techniques, this study estimates that over 16 ha of wall space has potential for greening in Melbourne's CBD, with 1.8 ha showing optimal characteristics.     

The effects of naturalness,gender, and age on how urban green space is perceived and used

Neighbourhood green space serves an important function for the urban population, and provides valuable ecosystem services for human well-being. In this article, we investigate the effects of naturalness, gender, and age on the activities, aesthetics, and self-reported well-being associated with urban green space. Our findings are based on a postal survey of residents living in close proximity to six different green spaces in the city of Gothenburg, Sweden. It is shown that higher perceived naturalness generated more activities and higher aesthetic values and self-reported well-being for residents living close to urban green spaces. The results also indicated that, regardless of the type of naturalness, women were more active in urban green spaces than were men. Women also saw greater aesthetic value in green spaces than men did, and had higher self-reported well-being associated with the urban green spaces. Finally, older residents were shown to participate in a greater number of nature-related activities than younger residents. Older residents also saw greater aesthetic values and had higher self-reported well-being associated with urban green spaces than younger people did. Seemingly, this poses a considerable planning challenge if areas of perceived naturalness are to be retained in cities, since the present trend is for reduced green spaces in cities and a ‘parkification’ of surviving natural areas. Further, because of the importance of perceived natural areas to the elderly, and in particularly women, distances to urban green areas should not be too great.     

Drivers of spontaneous and cultivated species diversity in the tropical city of Zhanjiang,China

Urban plant diversity influences the social functioning and well-being of urban dwellers. However, the patterns and drivers of plant diversity in tropical urban areas are still not entirely understood. In response to the knowledge deficiencies in this area, we investigated spontaneous and cultivated plant richness and their phylogenetic diversity and relatedness in 260 Urban Functional Units (UFUs), which represented nine different land use types according to anthropogenic function, in the tropical coastal city of Zhanjiang, China. Plant diversity was modelled as a function of UFU characteristics and human maintenance practices. Spontaneous species richness was highest in urban villages and vacant lands and lowest in transportation areas, while phylogenetic diversity was highest in utilities and lowest in parks. In comparison, cultivated species richness was highest in multi-family residential areas and lowest in vacant lands, while phylogenetic diversity of cultivated species was highest in commercial/industry areas and lowest in agriculture areas. The number of cultivated species and the degree of phylogenetic relatedness of spontaneous species were positively correlated with the human population density. The phylogenetic diversity of cultivated species within UFUs was generally higher than that of spontaneous species. Human maintenance of landscapes acted as an environmental filter for spontaneous species, but also promoted the number of cultivated plants. We conclude that appropriate investment in urban green areas may improve both plant species richness and phylogenetic diversity in urban environments.     

Role of green roofs in urban connectivity,an exploratory approach using landscape graphs in the city of Paris,France

Green roofs provide many ecosystem services, but little is known about the way they contribute to urban functional connectivity. This paper has the following four objectives: (1) to compare the potential green roofs’ role to connectivity in relation to other urban green spaces, (2) to specify the green roofs contribution’s type, (3) to explore the influence of building height integration method and finally (4) to assess the impact on connectivity of simulated greening new roofs. Using a landscape graph approach, we modeled ecological networks of three species groups with different dispersion capacities in the Paris region (France). Then, we computed several connectivity metrics to assess the potential contribution of green roofs to functional connectivity. At a large scale (metropole scale), our results show that green roofs can slightly improve the global connectivity largely through the connections rather than the addition of habitat area. More than a stepping stone function, green roofs would have a dispersion flux function at a local scale. Furthermore, when the difficulty of crossing movement is exponential to the height of buildings, green roofs over 20 m high are mostly disconnected from the ecological networks. In addition to the green roof’s height, our analysis highlights the very strong role played by buildings’ configuration. This study raises promising directions for the integration of building height into the analysis of urban connectivity. Detailed research and long-term biological data from green roofs and green spaces are needed to confirm our results.     

Value negotiation and professional self-regulation – Environmental concern in the design of the built environment

Built environment design professionals balance competing requirements for human comfort, aesthetics and ecological integrity in their projects. Among them, landscape designers play an important role in optimising the benefits derived from urban green spaces. This study critically considers value dimensions and domains that impinge on professionals’ decision making and environmental values that are applicable to built environment design. It specifically identifies the dominant group-based value domains and environmental values in local practice and examines how landscape designers determine the relative importance of competing values in urban South Africa. The study made use of semi-structured interviews with long-standing figures in the industry. The findings indicate that the political change, the economy and the varied climate and landscape character are contextual influences that strongly shape regional social constructions of urban nature. These constructions emphasise instrumental utility values that juxtapose fundamental values and overshadow less urgent eudemonistic and intrinsic environmental values. In the design process, designers trade off artistic pursuits for utility values, with implications for aesthetics and quality. The contextual influences undermine value pluralism. Current trade-offs arguably perpetuate a local legacy of the uneven distribution of quality green spaces. Promisingly, designers show environmental concern and value for sustainability, indigenous plants, utility, quality and safety. The potential for designers to strengthen bonds with urban nature lies in the creation of aesthetic experiences that build on existing local affinities to landscape character and indigenous species. Professional bodies have an important task to assist built environment designers in creating cities that preserve human-nature relationships.