The importance of blue and green landscape connectivity for biodiversity in urban ponds

The negative impact of urbanization on biodiversity can be buffered by blue (e.g., rivers, ponds) and green (e.g., parks, forests) spaces. However, to prevent biodiversity loss and reduce the risk of local extinctions, blue and green spaces need to be connected by corridors, so that organisms may disperse between sites. Landscape connectivity affects local community composition and metacommunity dynamics by facilitating dispersal. The goal of this study was to test the relative roles of pond environmental properties, spatial structure, and functional landscape connectivity on differentiation of invertebrate metacommunities in urban ponds in the city of Stockholm, Sweden. We characterized functional connectivity as blue connectivity (distance to water bodies), green connectivity (land use), and combined blue-green connectivity. We estimated functional connectivity by using electrical circuit theory to identify dispersal corridors. Interestingly, while circuit theory is often used in single-taxon studies, this method has rarely been applied to multiple taxa forming a metacommunity, as we have done in this study. Indeed, our study contributes toward an increased focus on the role of dispersal at the metacommunity level. We determined that functional connectivity was the most important factor in explaining community differentiation, with the local environment contributing comparatively little, and spatial structure the least. Combined blue-green functional connectivity had a major influence on structuring urban pond communities, explaining 7.8% of the variance in community composition across ponds. Furthermore, we found that increased functional connectivity was associated with an increase in the number of species. In summary, our results suggest that to preserve biodiversity in urban ponds, it is important to enhance functional connectivity, and that open green spaces could augment blue corridors in maintaining functional connectivity in urban pond metacommunities. To generalize these findings, future urban biodiversity studies should compare how functional connectivity affects metacommunities across multiple major cities.     

基于步行指数的深圳市福田区公园绿地社会服务功能研究

城市公园绿地是当代城市的重要组成部分,居民能否方便地享用公园绿地所提供的各项服务与功能,是衡量一个城市人地关系和谐状况、现代化发展水平和居民生活质量的重要指标,也是城市公园绿地社会服务功能的体现。选取深圳市福田区为研究对象,计算单点绿地步行指数,衡量均质区域的公园绿地步行可达性;基于土地利用类型法实现人口数据空间化;基于面域绿地步行指数耦合绿地空间分布与人口格局,评估深圳市福田区居民通过步行方式到达城市公园绿地的便利程度,即城市公园绿地的社会服务功能水平。结果表明:深圳市福田区在区域均质假设下,公园绿地步行可达性整体较好,区域差异较大,呈现出东优西劣的趋势,梅林公园周边、莲花山公园南部、荔枝公园周边及皇岗公园周边是四个公园绿地步行可达性最好的区域,福田区西北部和西南部公园绿地步行可达性差;供需平衡视角下,70%街道的居民可以便捷、公平地享用城市公园绿地所提供的服务,华强北街道、莲花街道、园岭街道和华富街道公园绿地设施建设非常完善,且绿地格局与人口格局配置合理,香蜜湖街道与沙头街道开放性公园绿地建设状况有待改进。将步行指数应用于公园绿地建设状况评估,为步行城市建设、公园绿地空间布局优化提供参考依据。     

Influence of urbanization on ant distribution in parks of Tokyo and Chiba City,Japan I. Analysis of ant species richness

To investigate how progressive urbanization influences the distribution of ant species in cities, I compared the ant species richness in urban parks of different areas and ages of Tokyo, the most intensively developed urban region in Japan, and its developing neighbor, Chiba City. A total of 43 ant species were found from 98 parks. Multiple regression analysis revealed that park area and age had a positive effect on the number of ant species in the parks and that the parks in Tokyo contained fewer species than did comparable parks in Chiba. Thus, the progression of urbanization reduces ant species richness in urban parks, most likely because it isolates the parks from the surrounding area. Next, in order to examine the relationships between the types of landform modification and the ant distribution in urban areas, I compared the ant species richness in urban parks of Chiba City among different landform types (upland + terraces, lowlands, cut and fill, banking, and reclamation). This study showed that the parks in the reclaimed lands and lowlands contained fewer ant species than did parks in other areas. The reason for this decline of ant fauna is discussed.     

Blood-sucking ticks (Acarina,Ixodoidea) as an essential component of the urban environment

The problem of urban ticks has arisen from the increased rate of urbanization since WWII. Expansion of municipal boundaries encompasses adjacent territories, so that large areas of wilderness together with all their inhabitants get incorporated into city limits. Current strategies of biodiversity conservation include the creation of green corridors and other forms of connectivity between wilderness and urban areas as well as between green patches within cities. All this allows various mammals and birds to migrate from their native habitats into and between various parts of the cities and to establish permanent urban populations. Medium-sized and larger animals provide adult ticks with blood meal, thus creating suitable conditions for the establishment and persistence of tick populations. Independent tick populations can exist in urban forests, parks, private properties, old cemeteries, etc. Over the last decades, the tick populations that originated from those in natural habitats around the cities have become a permanent component of urban fauna. Among such ticks, the castor bean tick Ixodes ricinus is the most important species for European cities, while the deer tick I. scapularis is of great significance for the East Coast of the United States. The taiga tick I. persulcatus is the most important species for the Russian cities and towns within its range. All these and some other ticks aggressively attack humans and their pets inside cities. The tick species especially well adapted to urban life are those which can live and reproduce in buildings. The brown dog tick Rhipicephalus sanguineus (family Ixodidae), the pigeon ticks from the reflexus group of the genus Argas, and Ornithodoros ticks (family Argasidae), which form urban and semi-urban populations, are the main urban tick pests and vectors. House infestation by ticks can lead to human infection with tick-borne pathogens or severe allergic reactions. Some tick hosts, mammals as well as birds, maintain tick-transmitted pathogens and serve as competent reservoir hosts. Urban populations of these animals can participate in the circulation of some pathogens within cities. Thus, the enlargement of urban green areas followed by their population by wild mammals and birds create good opportunities for the establishment of urban populations of tick vectors with the resulting threat to the health of urban dwellers and their pets. At the same time, our understanding of the real scope and complexity of the problem of urban ticks is far from being sufficient. Finding the ways of protecting the environment without increasing the risk to human health in modern cities is a pressing and challenging problem of our time.     

基于Landsat-8影像的沿海城市公园冷岛效应——以厦门为例

城市公园主要由水体和绿色植被等景观构成,其形成的公园冷岛（Park cool island,PCI）已成为减缓城市热岛效应的重要途径之一。采用景感生态学中的景感营造理念规划设计城市公园或优化公园空间结构有助于增强公园冷岛效应,进一步改善局地城市热环境。选择沿海城市——厦门市为研究对象,基于2013年8月的Landsat-8 OLI/TIRS遥感影像和Google Earth高分影像数据,首先提取了研究区15个公园的土地利用信息,采用改进的地表温度单通道算法,获取了城市公园地表温度数据,并采用缓冲区分析、景观格局指数和多元统计等方法定量分析公园内部平均地表温度、城市公园冷岛强度（即降温幅度）、公园冷岛影响距离（即对周边区域的降温范围）三者的主要影响因子,并利用景感生态学原理初步剖析了城市公园景感营造的原则。结果显示：（1）公园面积和公园建设用地面积是影响公园平均温度的关键因子（R²=0.915）,这两个因子与公园平均温度均呈显著非线性相关;公园面积存在阈值55 hm²左右;（2）公园冷岛PCI强度由公园绿地面积、公园建筑面积和面积-周长形状指数（P/A）三个因子决定（R²=0.911）;公园冷岛PCI强度与公园绿地面积呈显著非线性正相关,与公园建筑面积呈显著非线性负相关,与面积-周长形状指数（P/A）呈显著线性负相关;在确保公园绿地面积达到一定阈值时,应该尽量降低公园建筑面积,增加公园形状复杂度,有利于其PCI强度的增加,缓解城市热岛效应;（3）公园冷岛影响距离由公园面积和公园水体面积比例决定（R²=0.719）,公园冷岛影响距离与两者呈显著正相关;绿地公园中提高公园水体的面积比例,有助于增大公园冷岛的影响距离;（4）城市公园的规划与设计,需要运用景感生态学的原理,从缓解城市热岛效应的角度,充分考虑公园大小、形状、土地利用类型组成比例及空间配置等因素。     

转型中工业城市的公园绿地社会公平性研究——以东莞市东城街道为例

作为城市重要的生态空间,公园绿地为城市提供环境基础及景观保障,其资源的合理分配是社会公平的重要体现。提出公园绿地社会公平性新的内涵,即无论个体所处的人居环境条件如何,其获得的城市公园绿地质量应该平等。工业城市向服务型、创新型城市的转变是中国城镇发展的典型趋势,研究其公园绿地的社会公平性为城市更新改造与公共资源分配提供重要的科学依据。以东莞市东城街道为例,构建社会-经济-自然复合人居指标体系与公园质量评价体系,基于可达性模型与Pearson相关性系数对公平性进行测度。结果表明：由于区域更新强度及顺序不同,研究区的绿地布局存在不公平现象,居民享受的公园质量与小区的自然、经济要素具有一定的关联。转型中的工业城市高质量公园聚集于风景资源优越的高端居住区,其他公园质量普遍不佳。工业园区以及旧城区为公园服务盲区的主要聚集地。     

Colonization and extinction dynamics among the plant species at tree bases in Paris (France)

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Seasonal patterns of habitat selection of the House Sparrow Passer domesticus in the urban landscape of Valencia (Spain)

The habitat selection and the factors influencing the distribution of the House Sparrow Passer domesticus in the municipality of Valencia (76 km²) were studied during the winter and breeding season. House Sparrows positively selected urban parks and gardens, patches of derelict land and horticultural fields; they avoided the built-up habitat and the orange groves. In the urban landscape, the abundance of sparrows peaked in areas providing intermediate cover of the built-up habitat; it was positively driven by the amount of park land per unit area, and negatively by the size of urban parks. Our results suggest that the conservation and habitat enhancement of even the smallest parks and gardens are likely key factors in addressing the decline of the House Sparrow in many cities.     

Indicators for quantitative evaluation of the social services function of urban greenbelt systems: A case study of shenzhen,China

Existing ecological service assessments of urban green space have concentrated on natural environment, while research on the social services function remains underexplored. Taking Shenzhen as an example, this study starts with integrating the function of green space system with human needs. An indicator assessment technique that combines spatialization, rasterization and detailed of land ecological assessment was established with regard to the benefits of landscape aesthetics, function of disaster prevention and mitigation, and accessibility of park greenbelts. The results show that Shenzhen has very high recreational and cultural value, as the areas above medium level account for 66% of the city’s land area, and the recreational and cultural services are worth approximately 40.8million Yuan. Forest parks and comprehensive parks are important places to carry out social service function, particularly the disaster prevention and mitigation function, and the green spaces for disaster prevention and mitigation can be found in most of the disaster-prone areas. The accessibility of service shows a certain level of centrality, since the highest grade is concentrated in the central Bao’an, central Longgang, and the central part of the city. Based on the GIS overlay analysis, this study recognizes the distribution of essential patches, and constructs the structure of essential patches in urban green greenbelt systems by a combination of point, line, and surface elements. It shows the services of the Shenzhen greenbelt system have high potential for social integration, and this study also discusses the policy implication for macro decision-making. The assessment results objectively reflect multiple social services of the green space system in this region and provide a reference for the management, planning and construction of urban ecology in similar cities.     

基于遥感的夏季西安城市公园"冷效应"研究

城市公园景观作为城市绿洲区对城市生态环境特别是局地热环境的调节和改善起着极其重要的作用.以热红外遥感数据为信息源,以遥感定量反演和地理信息空间分析技术为支撑,对西安市城区7个主要公园对周边区域热环境的降温效应进行了研究.结果表明:降温幅度(△T)与远离公园的距离(L)两者间呈现非线性的关系特征;不同形态参数的公园对其周边区域的热环境影响不同,公园降温范围与公园绿地面积和水体面积呈现较强的正相关关系;公园水体面积比例≥30％时,其平均降温影响范围和降温幅度均高于水体面积比例低于30％的公园.因此,城市公园建设,不仅要考虑公园面积和形状,亦要考虑水体比例,一般说来,水体面积占公园面积30％以上为佳.基于热红外遥感数据对城市公园影响周边区域的范围和强度进行了定量探讨,所得结论对指导城市公园的规划与建设具有实用价值和参考意义.     

Public Parks and Wellbeing in Urban Areas of the United States

Sustainable development efforts in urban areas often focus on understanding and managing factors that influence all aspects of health and wellbeing. Research has shown that public parks and green space provide a variety of physical, psychological, and social benefits to urban residents, but few studies have examined the influence of parks on comprehensive measures of subjective wellbeing at the city level. Using 2014 data from 44 U.S. cities, we evaluated the relationship between urban park quantity, quality, and accessibility and aggregate self-reported scores on the Gallup-Healthways Wellbeing Index (WBI), which considers five different domains of wellbeing (e.g., physical, community, social, financial, and purpose). In addition to park-related variables, our best-fitting OLS regression models selected using an information theory approach controlled for a variety of other typical geographic and socio-demographic correlates of wellbeing. Park quantity (measured as the percentage of city area covered by public parks) was among the strongest predictors of overall wellbeing, and the strength of this relationship appeared to be driven by parks’ contributions to physical and community wellbeing. Park quality (measured as per capita spending on parks) and accessibility (measured as the overall percentage of a city’s population within ½ mile of parks) were also positively associated with wellbeing, though these relationships were not significant. Results suggest that expansive park networks are linked to multiple aspects of health and wellbeing in cities and positively impact urban quality of life.     

Typification of urban habitats,with ant assemblages of Moscow city taken as an example

A typification of Moscow city habitats is undertaken, based on their consideration as mosaic of patches and using such fundamental parameters as habitat origin (soil type), floristic composition, vegetation structure, and area of the biotopes. Altogether, 11 habitat types are distinguished: lawns, agrocenoses, xerophytic and mesophytic meadows, tall weeds, boulevards, small degenerative parks, small oppressed artificial parks, landscape parks, forest parks, and technocenoses. Such a classification is primarily useful for studying ants. The present paper describes the basic structure of ant assemblages in most types of urban biocenoses. The main pool of Moscow’s ant species ranked by their occurrence is as follows: Lasius niger (87%), Myrmica rugulosa (44%), Myrmica rubra (33%), Formica cunicularia (11%), Myrmica ruginodis (10%), etc. Leaf litter removal with a rake was shown to negatively affect the numbers, biomass, and species diversity of ant communities in urban areas with trees. The most stable two-species ant community revealed in Moscow City, termed an “elementary urban community,” consists of L. niger and M. rugulosa, with the former always outnumbering the latter.     

Butterfly Communities of Urban Forest Fragments in Campinas, São Paulo, Brazil: Structure, Instability, Environmental Correlates, and Conservation

A comparative study of butterfly communities in 15 urban/suburban remnants of tropical semideciduous forest in Campinas (São Paulo state, SE Brazil; 24°S, 47°W), with areas from 1.0 to 252ha and widely varying histories and environments, shows that the most significant factors, besides area and sampling time, distinguishing the sites and influencing their diversity (80–702 species) and composition are connectivity, permanent water, vegetation, flowers, and human impact (negative, including pollution). The diversified Nymphalidae butterflies (38–213 species) and especially two fermented-bait-attracted groups (Satyrinae, 2–30 species, and Biblidini, 9–44 species), are among the more useful indicators of the quality and diversity of the environments in these fragments. Effective conservation of butterfly communities in tropical cities may be achieved by maintenance of arboreal green corridors along streets and watercourses between moderately large (>10ha) humid areas, not near to the most built-up or polluted city centre(s), and the inclusion within these areas of ponds or streams, diversified native forest, and open vegetation including abundant nectar-rich flowers.     

基于形态学空间格局和空间主成分的贵阳市中心城区生态网络构建

喀斯特多山地区,城市扩展过程中大量自然山体镶嵌入城,形成具有多种生态系统服务功能的城市遗存自然山体。但在城市内部致密化发展过程中,这些城市遗存山体常被城市建设用地孤立和包围,形成人工干扰场中的生态孤岛。生态网络的构建既有利于城市遗存自然山体自然资源保护,又有助于丰富城市绿色基础设施生态系统服务功能。以喀斯特地区典型的多山城市——贵阳市行政区为研究对象,综合利用形态学空间格局分析法和景观连通性识别中心城区生态源地,基于主成分分析确定研究区综合阻力面,通过最小累积阻力模型、重力模型和水文分析等方法,识别并优化关键衔接廊道及节点,在中心城区行政区和建成区两个尺度构建研究区生态网络。结果表明：（1）行政区生态源地分布整体呈现"南北相望"的格局,建成区生态源地集中在中部;（2）研究区综合生态阻力高值主要集中在研究区中部,呈放射状向外扩散,综合生态阻力低值主要分布在研究区周边,以大型林地斑块为主;（3）行政区极重要、重要、一般廊道数分别为15、21、69,极重要廊道集中分布在北部,建成区极重要、重要、一般廊道数分别为37、113、227条,极重要廊道主要分布在建成区中部;（4）行政区和建成区一类生态节点分别为29、25个,二类生态节点33、17个。最终通过叠加行政区和建成区生态网络要素,形成贵阳市中心城区生态网络,研究结果能为贵阳市中心城区在未来用地空间上协调生态保护与城市发展提供科学合理的参考。     

基于生态系统服务供需的雄安新区生态网络构建与优化

城市生态网络构建是城市生态系统服务有效发挥作用的保障,构建完善的生态网络对于城市生态格局的优化具有重要的意义。结合雄安新区总体规划,通过雄安新区生态系统服务供给、需求两个层面识别生态源地。基于源地-缓冲区-廊道-节点框架,构建新区生态网络。其中,基于生态源地与城镇用地驱动因子,运用最小累积阻力方法得到累积阻力差,构建新区三生空间布局。根据成本距离分析和路径分析,结合雄安新区规划绿带分布,生成生态廊道,并在廊道与廊道交汇点、重要生态功能与脆弱的关键点以及道路轨道交汇点识别生态节点。得出：（1）新区生态源地主要位于白洋淀、公园绿地与其他绿地,分为水域生态源和林地生态源两类生态源地,面积总共728 km²。城镇源地主要位于新区东部容城县与雄县城区以及一些零星的农村居民点区域,面积为166 km²。（2）在新区三生空间布局下,加强生态廊道的构建,提升生态源地之间、生态源地与城镇源地之间的连通性,新区生态廊道主要依赖河流廊道和林地廊道两种类型。（3）在新区未来生态网络的建设中,需要重点关注河流廊道交汇点、河流廊道与城区的交汇处、交通道路与生态用地交汇处等的生态节点的建设及其生态功能的提升。     

基于生态绿当量的城市土地利用结构优化——以宁国市为例

基于生态绿当量的概念,探讨了城市生态用地合理性的生态标准,构建了土地利用结构优化模型。并在此基础上,以安徽省宁国市为例对该研究区不同空间范围下生态用地的结构及其优化方法进行实例分析。分析结果表明:宁国市域和城乡结合部均达到最佳绿地覆盖率的要求,而城区综合绿当量仅为0.66,需要进行用地调整。市域、城乡结合部和城区3个空间范围下的绿容率(GPR)分别为:4.89、4.22和2.77,可见城区绿化结构简单,树种单一,乔木和水体景观缺乏。同时,城区人口密集,但绿地生态系统服务功能较低,人均绿地率(ELP)仅为41.7 hm²/人。由此提出宁国市城区土地利用结构的优化调整方案,通过整个城市中心增绿、外围拓展;路林结合,蓝、绿交融,城乡一体,构筑内外环抱的多功能、多效益、完整的城市发展生态网架,保障城市长远的生态安全,促进良好的城市生态环境的形成。     

Slimes in the city: The diversity of myxomycetes from inner-city and semi-urban parks in Sydney,Australia

Natural and agricultural areas are rapidly becoming urbanised, causing changes in habitat structure and diversity. Although the effect of urbanisation on the diversity of terrestrial plants and animals has been well studied, there is a significant gap in our understanding of how urbanisation impacts diversity in protists. Here, we measure the diversity of plasmodial slime moulds (a group of large, macroscopic protists also known as myxomycetes) in inner-city and semi-urban parks. We studied the impact of a range of environmental characteristics (pH, temperature, canopy cover, area of green space and substrate type) on species richness and composition of myxomycetes. We also examined the influence of different degrees of urban development surrounding these parks. Species composition was significantly different between substrate types but not between inner-city and semi-urban parks. Temperature was the only environmental characteristic that affected diversity, having a negative effect on myxomycete presence. Our findings suggest that myxomycete diversity in urban parks is driven by factors at the substrate level, and not by the park's location within the city (inner city or semi-urban).     

Spatial patterns,hotspot, and risk assessment of heavy metals in different land uses of urban soils (case study: Malayer city)

A study on identification of hotspots, spatial patterns, and risk evaluation of heavy metals in urban soils of Malayer city (Iran) was carried out. Fifty-nine composite surface soil samples were collected from six different land uses (urban parks, streets, and squares, boulevards, residential and agricultural areas) in Malayer city, and the total heavy metals were measured by atomic absorption spectroscopy. Average concentrations of Cd, Pb, Cu, and Zn, As, Cd, and Pb were 0.66, 15.51, 12.25, and 96.8 mg/kg, respectively. Among the six land uses, heavy metal contamination was heavier for street, while low contamination could be found for residential and urban parks. The spatial distribution of Pb in surface soil was similar to those of Cd, and Cu was similar to those of Zn with decreasing values from the central areas to the suburb. Also, there were several hotspots for studied heavy metals that Cd and Pb were mainly occurred in locations of heavy traffic in the city center and Cu and Zn in the west and northwestern in the city. The calculated result of risk evaluation showed that much of the city suffered from moderate to severe pollution by four of these heavy metals.     

Factors affecting the abundance of House Sparrows Passer domesticus in urban areas of southeast of Spain

Capsule: House Sparrows Passer domesticus in the Valencian Community, where the species is declining, were more abundant in parks and urban areas where rubbish bins are available as a source of food. In heavy traffic areas, crowded streets and high-rise building zones, the species was less abundant.

Aims: To explore biotic and abiotic factors affecting the abundance of urban House Sparrows. To infer the causes that might explain the urban decline and to propose measures that might halt it and elevate population numbers.

Methods: The abundance of urban House Sparrows was analysed in relation to 17 landscape variables by carrying out 181 point counts (50 urban parks/38 schools/93 streets) per season across six locations and over five seasons (breeding and non-breeding seasons) in southeast Spain. Urban parks were also described by 21 additional variables. Hierarchical partitioning analyses were used to identify favoured or avoided urban factors by birds in each season.

Results: House Sparrows were most abundant in parks and other urban areas where rubbish bins were available as their foraging sites. The presence of rubbish bins, area and proximity to other parks favoured their abundance in parks. Furthermore, House Sparrows were less abundant in crowded streets, heavy traffic areas and high-rise buildings zones.

Conclusion: House Sparrows were present in high abundance where they feed but were scarce in polluted, crowded and heavily built-up areas of the city. Changes in the structure of these urban habitats may underlie the documented declines across Spain. Green urban planning and management are needed to ensure heterogeneous green areas with enough vegetation coverage to provide high availability of natural food versus anthropogenic food scraps. Sufficient numbers of buildings offering nest sites and reduced air pollution might ameliorate cities adequately to support larger populations of House Sparrows.     

海口市生态用地变化与安全格局构建

城市化过程中,城市生态用地变化与安全格局构建对于城市生态系统健康、城市居民生活质量和城市可持续发展有着重要意义,生态用地的变化直接影响生态安全格局变化,生态用地安全格局又对生态用地的规划有指导作用。基于GIS技术,对海口市1991年至2016年生态用地的时空变化过程进行研究,进而分析生态用地演变。选取高度、坡度、水资源安全作为生态安全影响单因子,并分级赋值,构建综合生态用地分布格局。以底线型生态用地为源,基于最小累计阻力模型(MCR),以阻力阈值作为分级边界,划分不同安全水平的生态用地区域,进而确定源间生态廊道、辐射道与战略点,构建生态用地安全格局。分析结果表明:1991年至2016年,海口市三类生态用地变化最大,其中林地减少13.33%,园地增加9.136%,坑塘水面增加3.71%。南渡江以西生态用地从以林地为主转为园地与建设用地为主,其余地区变化较少。生态用地安全变化区域集中在海口市西部与东部,其中西部高安全水平区减少,整体安全水平急剧恶化,东部高安全水平区略有提升。故需要制定和实施合理的生态用地保护政策,对生态用地格局进行优化调整,以期构建区域内生态环境协调发展的可行方案。