Assessing the species diversity and vulnerability of urban tree populations in the London borough of Westminster

The level of tree species diversity in urban tree populations can have serious implications for urban forest resilience and has a direct impact on ecosystem functioning at the local level. Few studies have measured the relationship between tree species diversity and vulnerability in UK urban forests. This study analysed the species composition, species diversity and the vulnerability to pests and diseases of 10,149 public trees in the London borough of Westminster across three land use types: housing, parks, and highways. Tree species diversity was significantly different across these land use types (Shannon’s diversity index (H) was 2.47 for housing sites, 1.63 for parks and 0.83 for highways) and we found that higher diversity appears to result in reduced vulnerability, evidenced by negative correlations between tree species diversity and susceptibility to pests and diseases. A stronger negative correlation was found between vulnerability and species richness than between vulnerability and Gini-Simpson’s diversity index. Our study reinforces the role of biodiversity indices in establishing and monitoring baseline levels of UK urban tree diversity. Our findings may inform future tree planting projects, help to ensure that development does not negatively affect urban tree diversity and inform proactive strategies for urban trees to contribute to wider biodiversity conservation.     

Quantification of the environmental effectiveness of nature-based solutions for increasing the resilience of cities under climate change

Nature-based solutions (NBSs) enhance the potential for mitigation and adaptation to climate change in cities. Among the environmental benefits offered by these measures, enhanced biodiversity, increased carbon storage, reduction of extreme temperatures, and pluvial flood control are crucial. The purpose of this study was to establish an integrated methodology for quantifying the benefits of NBSs and complementary measures and to apply it in a neighbourhood of Donostia-San Sebastián (Spain), where two alternative designs that incorporated NBSs and complementary measures were designed. Then, the individual effectiveness of the four variables was measured using both in-situ measurements and modelling approaches. For the integrated effectiveness, a multi-criteria decision analysis was employed. Both the ‘feasible’ design and the ‘ideal’ one led to an increase in biodiversity (46 and 108 %, respectively) and carbon storage (50 and 130 %, respectively). When considering each measure independently, putting soil provided the highest benefits for carbon capture and biodiversity; meanwhile, planting woody species and installing light-coloured permeable pavements and water fountains reduced the mean radiant temperature by 26.5 K and the air temperature by 0.5 and 2.5 K, respectively, in specific places. Finally, the importance of quantifying the multiple environmental benefits of NBSs for the selection of climate-smart options in urban planning has been highlighted.     

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.     

人工技术土壤研究进展与展望

城市绿色基础设施可以解决由城市化引发的诸多环境问题，但城市绿色基础设施建设所需要的大量土壤资源却很匮乏。人工技术土壤（Constructed Technosols, CT）是利用有机和无机固体废弃物创造的用于种植植物的新土壤，可通过调整组成材料和配方满足不同的植被类型、土地用途和立地条件等要求，最终回归城市，用于绿色基础设施建设。CT可同时缓解大量城市固废的处置难题和解决城市绿色基础设施建设的土壤缺乏问题，具有低碳、低成本、低影响的特点，还可产生经济效益。本文主要从CT对植物生长、碳捕获、生物多样性保护、径流污染物滤除方面的作用和人为生物调控方面介绍了CT的研究现状及在我国的应用潜力，并对CT的研究发展进行了展望，提出了一些CT研究中需要解决的问题与建议。旨在推动城市固体废物资源化综合利用和绿色基础设施低碳发展，增加城市碳固存，改善城市地区生态环境和增进人民健康福祉。     

A systematic review on the ecosystem services provided by green infrastructure

Urbanization and climate change are endangering the sustainability of public spaces through increased land artificialization, ecological fragmentation, reduced resource availability, and limited accessibility to natural and seminatural areas. Properly managing Green Infrastructure (GI) can contribute to mitigating these challenges by delivering multiple provisioning, regulating, supporting and cultural Ecosystem Services (ES). This would facilitate the implementation of strategically planned GI networks in cities for urban regeneration purposes. In this context, this study developed a systematic review on the ES provided by GI using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The analysis of 199 eligible articles indicated that more efforts should be made to address more ES at once, which connects to the need for conceiving GI as a strategically planned network of areas aimed at delivering diverse benefits. Based on the methods used in the items reviewed, geoprocessing tools and multi-criteria decision analysis are proposed to develop systems of indicators capable of accounting for multiple ES. These systems should also rely on multidisciplinary and participative procedures to encompass various facets of GI and represent the priorities of all relevant stakeholders.     

紫花苜蓿/豆科牧草间作的生态效益分析

为探究我国半干旱区紫花苜蓿(Medicago sativa)/豆科牧草适宜间作模式，本研究采用完全随机设计，以紫花苜蓿单作为对照，研究紫花苜蓿/3种豆科牧草(毛苕子(Vicia villosa)、箭筈豌豆(Vicia sativa)和豌豆(Pisum sativum))间作对土壤水分、杂草、捕食性节肢动物、饲草产量、水分利用效率和食物当量的影响。与紫花苜蓿单作相比，紫花苜蓿/毛苕子、紫花苜蓿/箭筈豌豆和紫花苜蓿/豌豆间作的紫花苜蓿全生育期干草产量分别提高30.2%,45.2%和61.3%;水分利用效率分别提高6.1,8.8和12.1 kg·hm^-2·mm^-1,食物当量分别提高26.74%,19.96%和53.28%。紫花苜蓿/豆科牧草间作显著降低土壤贮水量(P<0.05)、杂草密度和生物量，显著提高田间捕食性节肢动物密度、饲草产量、水分利用效率和食物当量，尤其紫花苜蓿/豌豆间作。紫花苜蓿/豌豆间作更有益于维持农田生态系统多样性和保持作物产量，可作为我国半干旱区可持续农业1种可行有效间作模式。     

宁夏贺兰山东麓葡萄园生物多样性的研究

宁夏贺兰山东麓属大陆性干旱半干旱气候，干燥少雨，具备生产优质酿酒葡萄的气候条件，同时具有天然的生态敏感性。葡萄园作为一个传统的典型农业生态系统，该区域内的生物多样性水平受当地生态气候、生产技术和管理模式等因素影响。本文以夏桐葡萄园作为调查样地，对植物和昆虫的生物多样性现状进行调查分析和科学评估，提出了葡萄园种植过程中提高生物多样性水平的相关建议与管理措施，以期为贺兰山东麓产区生态环境保护和生物多样性提升提供指导意见，助力葡萄酒产业可持续高质量发展。     

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.     

Insect biodiversity in urban tree pit habitats

Urban green spaces are important for urban insects, providing both habitat space as well as stopover locations within the urban landscape. Street tree pits in cities are small, heterogeneous, and understudied green spaces that may be important for supporting urban insect communities. The purpose of this study was to investigate the composition of insect communities within tree pits in New York City, New York, USA (NYC) and compare tree pit insect communities across NYC neighborhoods. Tree pits in NYC are part of the New York City Parks system but are primarily managed by residents of each street. We postulated that insect assemblages within tree pits would contain both permanent (habitat) and transient (stopover) members and those communities would vary among neighborhoods. Insects were collected from understory plants in tree pits in four NYC neighborhoods during the summer of 2019. We found that the tree pits provided habitat for nine orders and 51 families of insects, the majority of which were herbivores and their associated predators or parasitoids, which were likely utilizing the tree pits as habitat space. Few clearly transient species (e.g. pollinators) were collected. Furthermore, insect communities were similar both within neighborhoods and among neighborhoods, suggesting that while tree pits management is not strictly regulated in NYC, tree pits in all neighborhoods provided habitat to sustain similar insect assemblages. At the neighborhood level, urban tree pits can harbor a diverse insect community and that capability is similar throughout the urban landscape.