Urban green commons: Insights on urban common property systems   总被引：1，自引：0，他引：1  

Johan Colding  Stephan Barthel  Pim Bendt  Robbert Snep  Wim van der Knaap  Henrik Ernstson 《Global Environmental Change》2013,23(5):1039-1051

The aim of this paper is to shed new light on urban common property systems. We deal with urban commons in relation to urban green-space management, referring to them as urban green commons. Applying a property-rights analytic perspective, we synthesize information on urban green commons from three case-study regions in Sweden, Germany, and South Africa, and elaborate on their role for biodiversity conservation in urban settings, with a focus on business sites. Cases cover both formally established types of urban green commons and bottom-up emerged community-managed habitats. As our review demonstrates, the right to actively manage urban green space is a key characteristic of urban green commons whether ownership to land is in the private, public, the club realm domain, or constitutes a hybrid of these. We discuss the important linkages among urban common property systems, social–ecological learning, and management of ecosystem services and biodiversity. Several benefits can be associated with urban green commons, such as a reduction of costs for ecosystem management and as designs for reconnecting city-inhabitants to the biosphere. The emergence of urban green commons appears closely linked to dealing with societal crises and for reorganizing cities; hence, they play a key role in transforming cities toward more socially and ecologically benign environments. While a range of political questions circumscribe the feasibility of urban green commons, we discuss their usefulness in management of different types of urban habitats, their political justification and limitation, their potential for improved biodiversity conservation, and conditions for their emergence. We conclude by postulating some general policy advice.  相似文献   

四方湖湿地资源现状及保护管理对策   总被引：1，自引：0，他引：1  

郝静 《湿地科学与管理》2012,8(3):29-30

四方湖湿地是淮河中游重要的淡水湖泊湿地,生物多样性丰富,具有调蓄防洪、保护生物多样性、维护生态平衡等多项功能。由于不合理的开发利用,四方湖湿地生物多样性下降,生态环境出现了退化的趋势。采取有力措施,保护和恢复四方湖湿地生态功能,迫在眉睫。分析了四方湖湿地资源现状及存在问题,提出了四方湖湿地资源保护及恢复对策。  相似文献   

Notes on Mississippian echinoderms from Hurdlow,Derbyshire, central England     

Stephen K. Donovan  A.J. de Winter 《Proceedings of the Geologists' Association. Geologists' Association》2019,130(5):582-589

The fossil echinoderms of the Lower Carboniferous (Mississippian) of Derbyshire remain understudied, principally due to the nature of the preservation rather than any lack of biodiversity. Echinoids and crinoids are described in float blocks of limestone from near Hurdlow, Derbyshire, which have been etched naturally after many years of being washed by weakly acidic rain. Surface detail is variable, commonly poor, but rare specimens retain enough features for tentative identification. Two species of echinoids are identified from rare disarticulated plates, namely Melonechinus? sp. (ambulacral plates) and archaeocidarid sp. (interambulacral plate); more and superior material will be necessary to confirm this division. Crinoids include a cladid brachial ossicle sp. with a distinctive sculpture; a columnal of a monobathrid camerate platycrinitid sp.; Annulocolumnus (col.) sp. cf. A. annulus Donovan, a columnal morphotaxon with an unusually broad axial canal; and Cyclocyclicus (col.) spp. This is the tenth echinoid site to be recognized from the Mississippian of the White Peak. Examination of etched float blocks provides a further method of investigation of the echinoderm fauna of this and other limestone areas.  相似文献   

The effect of leaf-on and leaf-off forest canopy conditions on LiDAR derived estimations of forest structural diversity     

《International Journal of Applied Earth Observation and Geoinformation》2020

Forest structural diversity metrics describing diversity in tree size and crown shape within forest stands can be used as indicators of biodiversity. These diversity metrics can be generated using airborne laser scanning (LiDAR) data to provide a rapid and cost effective alternative to ground-based inspection. Measures of tree height derived from LiDAR can be significantly affected by the canopy conditions at the time of data collection, in particular whether the canopy is under leaf-on or leaf-off conditions, but there have been no studies of the effects on structural diversity metrics. The aim of this research is to assess whether leaf-on/leaf-off changes in canopy conditions during LiDAR data collection affect the accuracy of calculated forest structural diversity metrics. We undertook a quantitative analysis of LiDAR ground detection and return height, and return height diversity from two airborne laser scanning surveys collected under leaf-on and leaf-off conditions to assess initial dataset differences. LiDAR data were then regressed against field-derived tree size diversity measurements using diversity metrics from each LiDAR dataset in isolation and, where appropriate, a mixture of the two. Models utilising leaf-off LiDAR diversity variables described DBH diversity, crown length diversity and crown width diversity more successfully than leaf-on (leaf-on models resulted in R² values of 0.66, 0.38 and 0.16, respectively, and leaf-off models 0.67, 0.37 and 0.23, respectively). When LiDAR datasets were combined into one model to describe tree height diversity and DBH diversity the models described 75% and 69% of the variance (R² of 0.75 for tree height diversity and 0.69 for DBH diversity). The results suggest that tree height diversity models derived from airborne LiDAR, collected (and where appropriate combined) under any seasonal conditions, can be used to differentiate between simple single and diverse multiple storey forest structure with confidence.  相似文献   

Perceptions of Local People on the Use of Nyabarongo River Wetland and Its Conservation in Rwanda     

Venuste Nsengimana  Simeon Weihler  Beth A. Kaplin 《社会与自然资源》2017,30(1):3-15

This research presents a case study on perceptions of local people on the use of Nyabrongo river wetland and its conservation in Rwanda. It critically examines the potential implications of a shift in wetland use and management practices for local people and presents empirical data from a household survey, group discussions, and observations from transect walks. Results showed that the change in the use and management regime of Nyabarongo river wetland poses substantial loss for local people in terms of provision of resources, income, and access to the wetland, so that the majority of the participants are not happy with the current use of the wetland. Research concluded that there should be participation of all stakeholders, including local people, during policy development in order to shift from command-and-control toward local stakeholder integration in decision making.  相似文献   

城镇化对湿地的影响研究进展     

王娇月  韩耀鹏  刘丽丽  王丽  邴龙飞  尹岩  郗凤明 《湿地科学与管理》2017,(3):61-65

湿地是人类生存和发展的主要环境之一,城镇化进程严重影响了湿地生态系统。从城镇化对湿地的景观格局、水文、生物多样性影响方面综述了城镇化对湿地生态系统影响的研究进展。研究发现城镇化改变了湿地的景观格局,使湿地面积不断减少,景观破碎化,湿地异质性增大,连通性降低。城镇化改变了湿地的水文条件,使天然调蓄能力减弱,径流系数增强,洪峰流量增大,水土流失加重,河网和水系结构特征改变,水质受到严重影响。城镇化降低了湿地生物多样性,使物种丰富度和分布降低,珍稀物种因丧失生境而灭绝,生物入侵增强,进而导致种群组成和生态系统的功能发生变化。最后提出了在全球变化背景下城镇化对湿地影响研究的新方向及其保护措施建议。  相似文献   

Midlittoral polychaete communities in the Eastern Mediterranean Sea: new information from the implementation of the Natural Geography in Shore Areas (NaGISA) protocol and comparisons at local and regional scales          下载免费PDF全文

Georgios Chatzigeorgiou  Kleoniki Keklikoglou  Sarah Faulwetter  Fabio Badalamenti  Miltiadis‐Spyridon Kitsos  Christos Arvanitidis 《Marine Ecology》2017,38(1)

The aim of this study was to attempt to fill current knowledge gaps on midlittoral Mediterranean biodiversity at local and regional scales, by using benthic polychaetes as a model taxon. Two different data sets were analysed: (i) a quantitative data set from the two Natural Geography in Shore Areas (NaGISA) study sites in Crete and (ii) a qualitative data set from multiple sites across the Mediterranean. At the local scale, the results provide evidence that (i) discrete species communities are formed in midlittoral Mediterranean habitats, which vary by geographical location and year, depending on the scale of observation; (ii) macrophyte coverage and Chl‐a are the only environmental variables associated, albeit weakly, with the above pattern; (iii) although naturally disturbed, the Cretan NaGISA sites do not seem to experience any anthropogenic stress; (iv) environmental heterogeneity and history seem to be much less important in shaping the polychaete communities than inter‐specific interactions; however, it is not possible to specify at this stage whether local or regional processes or even their interactions may shape the polychaete communities. At the regional scale, the results indicate that (i) the only factor that seems to be involved in the regional pattern is the identity of the study providing the data sets, which implies variability and bias in how research projects are carried out, from the sampling design through to data collection and analysis; (ii) the Cretan NaGISA sites may be considered as representative of the habitat in the Mediterranean, under certain conditions.  相似文献   

日照近岸海域浒苔暴发区浮游植物调查研究          下载免费PDF全文

于洋  刘迎迎  王建勇  侯继灵  孟娜  牟秀菊  王珍珍  陈德春 《海洋开发与管理》2017,34(11):74-78

2016年5月和8月浒苔暴发前后,分别对日照近岸海域浒苔暴发区进行了两个航次的浮游植物断面调查。两个航次中,硅藻都占据了调查海域浮游植物组成的主导地位,在种类数上和细胞丰度值上都占了较大的比例。8月航次细胞丰度明显高于5月航次,这与调查海域的历次调查结果相一致。应用PRIMER软件中的单变量分析得到群落种数(S)、丰富度(d)、香农-威纳指数(Shannon-Weaner index)(H′)和均匀度(J),从多样性指数分析可以看出,5月航次的生物多样性优于8月航次,5月航次调查海域浮游植物种类数量和空间分布都较均匀。两个航次中出现的优势种存在较大差别。  相似文献   

生物可持续性科学计划与实施战略介绍     

李延梅  张志强  巩杰 《地球科学进展》2005,20(11):1262-1268

“生物可持续性”(bioSUSTAINABILITY)科学计划是生物多样性计划（DIVERSITAS）3个核心科学计划之一,是一个有关生物多样性的国际计划。bioSUSTAINABILITY有3个密切相关的研究焦点：①评价目前生物多样性保护和持续利用所采取的措施的有效性;②导致生物多样性丧失的社会、政治和经济驱动因子分析;③生物多样性保护与持续利用的社会选择和决策取向研究。介绍了bioSUSTAINABILITY的主要内容及其实施战略,并分析了它对保护和可持续利用生物多样性的重要作用。  相似文献   

Tidal exposure or microhabitats: what determines sandy‐beach nematode zonation? a case study of a macrotidal ridge‐and‐runnel sandy beach in Belgium     

Tatiana F. Maria  Jan Vanaverbeke  Ruth Gingold  André M. Esteves  Ann Vanreusel 《Marine Ecology》2013,34(2):207-217

Lately, across‐shore zonation has been found to be more important in structuring the nematode community of a tropical macrotidal sandy beach than microhabitat heterogeneity. To evaluate whether this zonation pattern applies to a temperate beach, a macrotidal ridge‐and‐runnels sandy beach in the North Sea was studied. We investigated whether a similar zonation occurs in sandbar and runnel microhabitats, and whether the runnels harbour a different community from the subtidal. Our results indicate that nematode communities from runnel and sandbar habitats are significantly different. In addition, horizontal zonation patterns for nematode communities differ between both habitats. Nematode assemblages from sandbars are divided to lower, middle and upper beach while upper and middle runnels cluster together. The subtidal and upper runnels showed dissimilar nematode assemblages, although runnels showed the same dominant species (Daptonema normandicum), which increases its abundance towards the upper runnels. This study illustrates the importance of microhabitat heterogeneity, which resulted in different zonation patterns across the sandy beach examined. The divergent zonation between sandbars and runnels in the macrotidal temperate sandy beach, compared with the pattern observed for a subtropical sandy beach with similar morphodynamics, indicates that generalizations about nematode distribution patterns should be made with caution.  相似文献