Urban forest research in the Mediterranean: A systematic review

The Mediterranean region is facing many challenges, some of which can be addressed by nature-based solutions such as urban forests and green space. However, at best, urban forest research from Mediterranean countries has been only briefly addressed in review papers up to date. This Scopus-based review paper provides first insights into the development of urban forest research in the Mediterranean in the 20-year period from 1996 to 2015. The purpose of the review was to a) analyse distribution of urban forest research in the Mediterranean and identify countries that are forerunners based on the number of publications, b) to analyse distribution of research themes across the Mediterranean and per country, and hence point to research gaps and needs. Researchers from Italy, Turkey and Spain were the most productive in the analysed period. Research is mainly concentrated in the North, while it is scarce to non-existent in South and Eastern Mediterranean countries (excluding Turkey and Greece). Papers dealing with pollution, human health and sociocultural values were the most frequent. Some countries exhibited research specialisation with regard to certain themes. For instance Italian researchers mostly focused on topics related to pollution and urban forest management, the majority of Spanish papers addressed urban forests in the context of human health, while sociocultural values were the main research theme for researchers from Turkey. Papers were analysed also based on research methods, approaches and study locations. Suggested future research includes analysis of the quality of knowledge related to urban forests in the Mediterranean as well as of collaboration between researchers, research institutions and countries.     

城市绿地土壤质量评价指标研究进展

城市绿地具有改善城市生态环境和美化城市景观、改善城市空气质量、调节小气候、降低城市灾害发生等多种生态功能。文章对城市绿地的概念、分类、功能,城市绿地土壤质量评价指标,如城市绿地土壤质量的理化性状、微生物学特性研究进行综述。     

How climate change perception is reshaping attitudes towards the functional benefits of urban trees and green space: Lessons from Hong Kong

Urban greening has rapidly emerged as a key urban climate change adaptation strategy. Urban greening is thought to confer manifold socio-ecological benefits upon residents in towns and cities. Yet proponents of urban greening have seldom considered how people’s support for greening policies may be shaped by weather and climate. This paper reports the results of exploratory research examining public expectations of adverse weather changes and people’s attitudes toward the functional benefits of urban trees and green space. Results of a questionnaire survey of 800 residents of Hong Kong indicate a positive relationship. Respondents tended to rate functional benefits as more important if they anticipated adverse weather changes in the near future, namely, rising temperatures, more tropical cyclones and prolonged rain. This subjective weather effect is more salient when these weather changes are perceived as a threat to one’s daily life. We found urban greenery is assigned a higher value by individuals concerned about exposure and vulnerability to climatic stressors. Affinity for greening appears to be related to how weather and climatic variability is perceived. This observation is informed by a broader geographic perspective, which construes weather and climate as part of the spatial environment in which urban nature is apprehended and comprehended. An explanation for our findings is that increasingly volatile weather can potentially reshape urban residents’ interactions with nature, based on perceived relief and/or protection from climate-related threats.     

Carbon sinks in urban public green spaces under carbon neutrality: A bibliometric analysis and systematic literature review

Urban green spaces play essential roles in regulating the global carbon cycle and reducing carbon dioxide (CO₂) emissions. However, research on the carbon sequestration efficiency of urban public green spaces, which is closely related to the human settlement environment, has not received enough attention. Thus, we systematically analyzed the existing literature in the Web of Science core database using bibliometrics and network analysis combined with the CiteSpace visualization tool. The aim of this review was to elucidate the focus and development trend of research conducted between 2007 and 2022 on carbon sinks in urban public green spaces. Our results demonstrated that: 1) Numbers of related publications are increasing annually, indicating that the subject is receiving increasing global attention. Related research topics primarily focus on two aspects: carbon sink measurement methods and sustainable carbon sink design for urban public green spaces. 2) Methods for measuring and monitoring carbon sinks in the urban public green spaces include sample plot measurement, the assimilation method, the micrometeorological method, the remote sensing (RS) estimation method, and laboratory work. Most methods follow the forestry system approach and lack the methods and techniques to directly assess the carbon sink effectiveness of urban public green spaces. 3) Key factors affecting the carbon sink capacity of urban public green spaces are: plant species selection, plant community structure, green space characteristics, and maintenance management. 4) Future research should focus on encouraging public participation in the design of sustainable carbon sinks in urban public green spaces, advancing biodiversity research on carbon sinks in urban public green spaces, and enhancing the precision of measurements while addressing regional differences. This study contributes to the integration of research on the effectiveness of carbon sinks in urban public green spaces and provides a theoretical reference and guidance reduces prospective urban emission and achieves climate goals.     

Impact of urban park’s tree,grass and waterbody on microclimate in hot summer days: A case study of Olympic Park in Beijing,China

Urban heat island (UHI) often cause negative impact and has been linked to heart stroke rate, morality, human comfort, energy consumption and air pollution. Fortunately, urban green spaces have been considered as an effective element to mitigate UHI through their cooling effect. However, further empirical research is necessary in order to efficiently guide the design and planning of urban green space. We observed the impacts of urban park's tree, grass and waterbody on microclimate inside the Olympic park of Beijing during summer days. The results indicated that, on average, the park was 0.48–1.12 °C cooler during the day, as well as increased air humidity 2.39–3.74% and reduced human comfort index 1.02–2.43 to generate more comfortable thermal environment. Urban park's cluster trees with short ground vegetation generated higher cooling effect than single trees, grass and waterbodies; proper irrigation regime enhanced the cooling effect of grasses, even the irrigated grass have similar cooling effect with small waterbody on sunny, windless summer days. Therefore, we advise to increase undergrowth coverage and grass irrigation management in order to take advantage of cooling effect of urban parks.     

南宁城市街旁绿地区域性景观探讨

城市街旁绿地是城市居民利用最为广泛的绿地之一,是城市园林形象的直接表现。南宁是一座无论在自然环境条件还是地方文化底蕴方面都极具特色的城市。为了创造出更宜人的城市街旁绿地空间,需要在园林设计中充分重视景观地域性。景观地域性的表达本质上也是对南宁地方文化的继承与发扬。     

浅谈景观小品在城市道路绿地中的应用——以黑龙江哈尔滨市为例

城市道路绿地是城市道路的组成部分,是环境绿化的重要组成成分,其景观反映了一个城市政治、经济、文化发展水平和城市形象的核心,同时也体现了城市总体园林面貌和独特个性。景观小品作为道路绿地景观的重要组成元素之一,在景观表达与功能满足等方面起到了重要作用。本文以哈尔滨主要道路绿地小品景观应用为例,在景观小品类型与实际应用方面进行研究与分析,提出其使用特点和存在问题及相关解决对策。     

Urban forest management and governance in Latin America and the Caribbean: A baseline study of stakeholder views

Cities in the Latin America and Caribbean (LAC) region and around the world are setting long-term greening goals that include planting more trees and increasing green cover. Research in LAC cities has mainly focused on biodiversity and vegetation, with little understanding of the mechanisms underlying the decisions through which stakeholders achieve urban greening. Exploring stakeholders’ views about urban forest management and governance can provide us with an opportunity to identify needs and research gaps for urban greening and urban forestry in LAC. To our knowledge, there has never been a region-wide empirical study to capture these stakeholder views. Here we explore how stakeholders working in urban forestry in LAC, including governmental, and non-governmental professionals, define urban forests, and view management and governance issues as well as educational opportunities. We used an online survey based on a combination of open- and closed-ended questions. The survey was delivered to participants at the first two regional conferences on urban forests in LAC organized by the United Nations. We collected 91 responses from stakeholders working in 50 different cities of varying population sizes across 6 LAC bioregions. Most respondents considered parks, planted green corridors, street trees, and remnant forests in urban and peri-urban areas as components of urban forests. Stakeholder views on management and governance were divided in two distinct perspectives, one dominated by public participation issues, and another one related to operational issues. Most respondents considered operational and management tools for urban forests to exist in LAC cities, but they disagreed on the existence of inventories, long-term strategies, and ways for the public to engage in urban forestry. Responses also revealed that some educational opportunities, such as arboricultural certification, are still relatively scarce and in high demand in the region. This study provides a regional baseline and first insights into a more diverse view of urban forestry which could be enriched with more empirical studies in the future.     

The relationship between urban green space and social health of individuals: A scoping review

Urban green space is an important resource to effectively improve the urban environment and human health. A growing body of evidence highlights their positive impact on physical, mental and social health. Less focus has been paid to the social health benefits of urban green space. Designing urban green space to improve the social health of various groups has become a crucial problem, given the lack of uniformity in defining and measuring social health, as well as the varying social health needs of different individuals. This review aims to explore the relationship between urban green space and social health of individuals, which is defined as how one gets along with other people, how other people react to him/her, and how one reacts with the social institutions and societal mores. According to the PRISMA extension for Scoping Review (PRISMA-ScR) guidelines, 60 articles published between 1998 and 2022 met the inclusion criteria were reviewed. The results demonstrated that different types of urban green space significantly influenced the social health of individuals. The dimensions of social health of individuals based on urban green space could be divided into four groups: social contacts, social relations, social support and social connections, which were mainly affected by the physical characteristics, perceptions, and usages of urban green space to varying degrees. Socio-demographic characteristics could moderate the strength and orientation of the relationship between urban green space and social health of individuals. As the first scoping review to analyze the relationship between urban green space and individual social health, this study not only provides evidence for the social health benefits of urban green space, but also offers information and tools for future research and policymakers.     

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.     

Selecting trees for urban paved sites in Scandinavia – A review of information on stress tolerance and its relation to the requirements of tree planners

Urban paved sites are complex stress environments and when selecting trees for such sites, tree planners must prioritise stress tolerance above aesthetic appeal and functional aspects. This requires detailed information about the tolerance of tree species to environmental stresses, so as to support urban tree planners in selecting a wide range of trees. In Scandinavia there is currently no overview of the extent to which the character of information about stress tolerance and its dissemination in books and papers support urban tree planners in selecting a wide range of species for paved sites. Books on dendrology, literature on plant use in cities, tree nursery catalogues and scientific papers were therefore reviewed. For the review, eight tree species were selected along a gradient representing their intensity of use in Northern Europe. We examined the character of information and assessed it relative to tree planners’ requirements for information to be; contextual, local to Scandinavia, referring to existing plantings in paved sites and recommendations for use of the species in paved sites. The results showed that existing information is piecemeal and that most is either too general (dendrology literature) or too specific or contradictory (scientific literature) to meet the requirements of urban tree planners, while books intended for plant use in cities do not sufficiently integrate the local perspective. Moreover, contextual information local to the Scandinavian region is mainly provided for already much used species. These findings led to suggestions on how future urban forestry and arboriculture research and dissemination efforts in Scandinavia can encourage tree planners to use a greater variety of tree species in urban paved sites.     

城市绿地减灾功能及防灾植物选择

在城市综合防灾减灾体系中,城市绿地占有十分重要的位置。城市绿地是城市规划和建设中的重要组成部分,它不仅具有美化城市环境、净化空气、平衡城市生态系统、为城市居民提供休憩游乐场所等作用,同时,还具有防震、防火、防洪、减轻灾害的功能。详细分析城市绿地在城市综合防灾减灾中的作用,并介绍城市防灾减灾植物的选择。     

Can urban green space cure homesickness? Case study on China poverty alleviation migrants in Anshun,Guizhou

With the implement of China's ex-situ poverty alleviation resettlement (ESPAR) policy, nearly 10 million rural population have relocated with a better living condition in a short period of time, most of which have migrated to urban areas. The living environment and lifestyle of the poverty alleviation migrants (PAMs) have undergone dramatic changes, the resulting mental health problems may seriously affect their social integration and well-being. In particular, homesickness is a prevalent mental problem among the PAMs that demand prompt attention. Research indicates that longing for natural environment is one of the major causes of homesickness among rural out-migrants. As the main natural environment in cities, urban green space has been proven by numerous studies to have a positive effect on residents' mental health in various aspects, including reducing anxiety, relieving fatigue, and fostering perseverance. However, few studies have focused on the influence of urban green space on the mental health of the PAMs, especially on alleviating their homesickness syndrome. Using the data collected from interviews and questionnaire survey in the PAMs’ resettlement sites in Anshun, Guizhou, which has undertaken a heavy poverty alleviation task, this study examined the relationship between the physical activity, environment, function of urban green space, and the severity of PAMs’ homesickness, meanwhile paying attention to the impacts caused by different socio-demographic characteristics. The results show that urban green space is strongly associated with alleviating PAMs’ homesickness, and that all three factors play a positive role. Neighborhood green space is used the most, but suburban green space seems to provide better alleviation of homesickness. This study sheds lights on the critical role of urban green space for promoting PAMs' mental health, and aims to provide scientific reference to the planning and improvement for future migrant resettlements and urban green space.     

Urban wild food foraging locations: Understanding selection criteria to inform green space planning and management

Urban wild food foraging is increasingly attracting attention as an activity in urban green spaces that encourages urban residents’ interaction with their natural environment. However, little is known about the criteria influencing urban foragers’ selection of foraging locations that could inform urban green space management and planning to encourage urban foraging. To elicit these criteria, we conducted 21 semi-structured expert interviews with urban foraging stakeholders in Vienna, Austria, and analysed the data using qualitative content analysis. The respondents suggested 11 criteria that influence the selection of foraging locations. These are related to spatial factors, management of public urban green spaces and the green space activities of other visitors. However, the respondents reported that urban foragers do not uniformly follow these different criteria, but subjectively assess and apply them depending on the specific locations and the plant materials and mushroom species being targeted. For some foragers, even intensively managed public urban green spaces can offer certain advantages. Thus, urban residents forage in public urban green spaces that have diverse properties and management strategies. We suggest that urban foraging is best supported by biodiversity- and wilderness-friendly green space management that supports access to foraging locations, clear foraging regulations and codes of conduct, and comprehensive information about contamination for urban residents. Implementation of these suggestions would not only benefit urban foraging, but also enhance urban biodiversity and guarantee the multifunctional benefits of public urban green spaces for urban residents and urban nature.     

城市绿地防灾避难功能评价指标体系研究

我国城市绿地经过多年的发展,已具有一定的系统和规模.目前,关于城市绿地系统的研究已不鲜见,但城市绿地防灾避难功能的研究才刚刚起步.现探讨城市绿地防灾避难功能评价指标体系,希望给城市防灾减灾体系建设提供规划和决策参考.     

How does enclosed private residential green space impact accessibility equity in urban regions? A case study in Shenzhen,China

Compared with public parks, residential quarter green space (RQGS) is a type of enclosed private green space that is located in residential areas and has higher visit frequency. Generally, in China residential areas with high housing prices have higher quality and more quantity of RQGS. Therefore, the differences in RQGS between residents with different socio-economic status may influence the equity of urban green space accessibility. However, due to the lack of data sources, few existing studies have taken RQGS into account as a part of urban green space supply resources. Based on multi-source geographic big data, this paper takes Shenzhen as the research area to explore the impact of RQGS on the spatial pattern and fair distribution of green space accessibility. The total green space accessibility (TGSA), which includes the accessibility of RQGS, and the public park accessibility (PPA) were calculated using the Gaussian-based two-step floating catchment area method (2SFCA). Using housing prices to indicate the income level of dwellers, bivariate Moran’s I and multiple regression were adopted to explore equity of urban green space accessibility. The main conclusions were: (1) The accessibility of green space increased by 27.97% on average after considering RQGS and ignoring RQGS could underestimate the accessibility of green space, particularly in the residential quarter with high housing prices near the city center. (2) The regression coefficients of housing prices with PPA and TGSA were 0.042 (p < 0.01) and 0.160 (p < 0.001), respectively, indicating that the advantages of high-income groups in RQGS may further exacerbate the inequity of urban green space accessibility. The research conclusions may provide a scientific basis for optimizing the spatial structure of green space in urban areas and ensuring the equitable distribution of green space.     

Greening cities through urban planning: A literature review on the uptake of concepts and methods in Stockholm

Nature-based solutions (NBS) represent the most recent of several "greening" concepts proposed to support spatial planning and decision-making towards sustainable metropolitan regions. Despite similarities, the concepts stem from different disciplines and policy arenas and reflect various models of people-nature relations. This paper aims to analyze the uptake of greening concepts in scientific planning literature focusing on (urban) nature and landscape in the metropolitan region of Stockholm, Sweden, over the last three decades. It investigates what changes this evolution has brought in terms of the topics adopted, methods applied, and types of planning support put into practice. We identified 574 articles that reflect substantial research on greening concepts in the Swedish planning context. The articles demonstrate an initial prevalence of biodiversity with later increases of interest in ecosystem services and NBS. A detailed analysis of the studies focusing on Stockholm revealed Population growth/densification, Green space management and Biodiversity conservation as the most commonly addressed societal challenges. The most frequently mentioned type of green and blue element is Parks and (semi-)natural urban green areas, including urban forests. Methods applied were mostly quantitative, while mixes with qualitative approaches were only apparent in ecosystem services articles. Half of the studies involved practitioners or decision-makers, but only four seemed related to real-life planning processes. Taken together, the influence of scientific literature on the uptake of greening concepts in spatial planning seems to have been limited. Future mainstreaming of greening concepts in Stockholm and beyond could benefit from available data, methods and experiences, but will require more active translation and boundary management. Further research into science-policy-planning interfaces at city scale is thus imperative to advance more sustainable pathways for people and nature in metropolitan regions.     

“绿量”在城市绿化中的应用研究

通过概述绿量概念的发展过程,介绍了绿量指标从二维平面到三维空间的进步,阐述了绿量概念和提出的意义,介绍了城市三维绿量的测算方法,指出了现在研究中存在的问题。希望通过对绿量概念的进一步阐述,将人们的思维引入到如何充分利用有限绿化空间、科学配置植物及对植物的生态效益进行量化的层面,进而营造较好的绿化模式,提高城市绿地的整体生态效益。     

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.     

Urban green spaces and sustainability: Exploring the ecosystem services and disservices of grassy lawns versus floral meadows

Urban green spaces provide important ecological, environmental, and cultural benefits, including biodiversity conservation and human wellbeing. However, a significant portion of urban green space is currently managed as highly manicured grassy lawns that provide limited ecosystem services. Managing urban green spaces as diverse meadows can have a multitude of ecosystem benefits such as biodiversity conservation, stormwater infiltration, and aesthetics. Relatively little is known about the range of ecosystem services or disservices in managing urban green spaces as lawns versus meadows. In this paper, we separately characterize three major categories of ecosystem services and disservices (provisioning, regulation and maintenance, and cultural) delivered by urban lawns and meadows while highlighting several trade-offs and synergies associated with urban lawn and meadow management strategies. Additionally, we suggest specific research priorities to better evaluate ecosystem services and disservices across these urban green spaces. Understanding ecological, environmental, and cultural trade-offs and synergies of managing different urban green spaces is key to maintaining multiple ecosystem services in urban environments.