Challenges and Opportunities in Implementing Managed Relocation for Conservation of Freshwater Species

Abstract: The rapidity of climate change is predicted to exceed the ability of many species to adapt or to disperse to more climatically favorable surroundings. Conservation of these species may require managed relocation (also called assisted migration or assisted colonization) of individuals to locations where the probability of their future persistence may be higher. The history of non‐native species throughout the world suggests managed relocation may not be applicable universally. Given the constrained existence of freshwater organisms within highly dendritic networks containing isolated ponds, lakes, and rivers, managed relocation may represent a useful conservation strategy. Yet, these same distinctive properties of freshwater ecosystems may increase the probability of unintended ecological consequences. We explored whether managed relocation is an ecologically sound conservation strategy for freshwater systems and provided guidelines for identifying candidates and localities for managed relocation. A comparison of ecological and life‐history traits of freshwater animals associated with high probabilities of extirpation and invasion suggests that it is possible to select species for managed relocation to minimize the likelihood of unintended effects to recipient ecosystems. We recommend that translocations occur within the species’ historical range and optimally within the same major river basin and that lacustrine and riverine species be translocated to physically isolated seepage lakes and upstream of natural or artificial barriers, respectively, to lower the risk of secondary spread across the landscape. We provide five core recommendations to enhance the scientific basis of guidelines for managed relocation in freshwater environments: adopt the term managed translocation to reflect the fact that individuals will not always be reintroduced within their historical native range; examine the trade‐off between facilitation of individual movement and the probability of range expansion of non‐native species; determine which species and locations might be immediately considered for managed translocation; adopt a hypothetico‐deductive framework by conducting experimental trials to introduce species of conservation concern into new areas within their historical range; build on previous research associated with species reintroductions through communication and synthesis of case studies.     

森林公园旅游开发环境影响评价技术和方法——以山东药乡国家森林公园旅游开发为例

森林公园旅游开发是区域开发的一种常见类型，其环境影响评价蕴含着丰富、复杂和值得深入研究的内容。本文着重探讨了评价指导思想、技术路线选择、评价指标体系、评价技术方法等几个关键问题，并以山东药乡国家森林公园旅游开发环境影响评价为例，进一步探讨了有关问题的具体解决办法。     

Landscape ecology of the region surrounding Qinghai Lake, Qinghai Province of China based on remote sensing

--A region surrounding Qinghai Lake was chosen as thestudy area and nine ecological landscape types that were recognizedbased on Landsat TM image classification of land cover/use typesalong with the ancillary data, and their ecological features andthe measures dealing with the eco-environmental problems arepresented in this paper. The study has shown that using thisapproach the ecological landscape types in a region like the studyarea can be readily recognized and their ecological features can berather accurately derived. Moreover, the deterioration in near alllandscape ecological types in the area is quite serious. Therefore,effective and proper measures have to be taken in order to realizea sustainable development of the region.     

Integrating the Metapopulation and Habitat Paradigms for Understanding Broad-Scale Declines of Species

Abstract:  Caughley (1994) argued that researchers working on threatened populations tended to follow the "small population paradigm" or the "declining population paradigm," and that greater integration of these paradigms was needed. Here I suggest that two related paradigms exist at the broader spatial scale, namely the metapopulation paradigm and habitat paradigm, and that these two paradigms also need to be integrated if we are to provide sound management advice. This integration is not trivial, and I outline five problems that need to be addressed: (1) habitat variables may not measure habitat quality, so site-specific data on vital rates are needed to resolve the effects of habitat quality and metapopulation dynamics; (2) measurements of vital rates may be confounded by movements; (3) vital rates may be density dependent; (4) vital rates may be affected by genotype; and (5) vital rates cannot be measured in unoccupied patches. I reviewed papers published in Conservation Biology from 1994 to 2003 and found 41 studies that analyzed data from 10 or more sites to understand the factors limiting species' distributions. Five of the analyses presented were purely within the metapopulation paradigm, 14 were purely within the habitat paradigm, 17 involved elements of both paradigms, and 7 were theoretically ambiguous (2 papers presented 2 distinct analyses and were counted twice). This suggests that many researchers appreciate the need to integrate the paradigms. Only one study, however, used data on vital rates to resolve the effects of habitat quality and metapopulation dynamics (problem 1), and this study did not address problems 2–5. I conclude that more intensive research incorporating site-specific data on vital rates and movement is needed to complement the numerous analyses of distributional data being produced.     

行政中心驻地对县域土地利用景观格局的影响研究

使用GIS（地理信息系统,Geographic Information System）的缓冲区法、空间叠置分析法以及景观格局分析法,分析不同等级的行政中心驻地对土地利用景观格局的影响。研究结果表明：（1）耕地是丰县的景观基质,聚落（城乡建设用地）景观是丰县主要的景观类型。与行政中心的距离越近,人为景观的面积比重就越高,大于各景观类型的现状比重,表现出较强烈的空间吸引特性;相反,自然景观所占比重远远低于现状比重,反映出较明显的空间排斥效应。（2）与镇政府的距离变大,土地利用景观的破碎程度、聚集程度、斑块形状的规则程度均先减弱后增强;与县政府驻地的距离变大,景观的破碎程度呈现“减弱-增强-稳定”模式,景观形状的复杂程度变大,聚集程度先减弱后稳定,景观的多样性与异质性受两等级行政中心驻地距离的影响程度均较小。（3）镇级、县级行政中心分别在1 500 m、3 000 m范围内对土地利用景观格局的影响程度大     

南洞庭湖湿地鱼类生境景观变化及其人为驱动

通过实地调查和制图分析,研究1983~2013年南洞庭湖区万子湖湿地和鱼类生境景观变化及其人为驱动,结果表明:湿地洲滩面积由1.410×104 hm2增加到2.135×104 hm2,敞水面面积由1.363×104 hm2减少到0.631×104 hm2;芦苇洲减少,但林地由0.056×104 hm2增加到0.728×104 hm2并扩展到保护区核心区;新增泥围21个、网围10个,引淤、沥水排水设施长度增加了201.71km。人为干扰对景观变化有极大影响,其中引种意大利杨及芦苇改变了地形和群落结构,挤占了自然演替条件下应有的草洲景观空间,使鱼类产卵、索饵的适宜生境减少;泥围作为有害渔法,与网围都处于建设发展阶段,占据了草洲、洼地等鱼类产卵、索饵的适宜生境;引淤渠建设使大面积湖泊快速淤积成洲,将水生生态景观转变为大多数时间干露的以陆相生态景观为主的水陆相生态景观,鱼类生境被压缩,并对南洞庭自然保护区核心区继续发挥促淤作用。     

茂兰自然保护区景观格局空间变化研究

为促进保护区生态环境和地区社会经济的可持续发展,应用2005、2010年茂兰地区高分辨率影像和1∶5万地形图,基于Arc GIS、FRAGSTATS软件平台,采用移动窗口法、DEM,对茂兰自然保护区景观格局的空间结构及其演化进行研究。结果表明:1)保护区景观格局呈明显的5个团状高值区,中心区域异质性显著;2)从实验区到核心区,SHDI下降65%,ED降幅46.73%,LSI下降49.71%,PD下降40.21%,同时CONTAG上升43.95%,LPI上升达107.01%,景观由实验区团状、均衡、破碎化,向南部农用地随道路的延伸而镶嵌分布的格局转化,其中缓冲区整体空间密度高,异质性强;3)研究区人工景观集中分布在坡度0°~5°之间,自然景观以35°~45°向两侧递减,5°~25°间面积最小,实验区格局演化呈良性,要防止居民点向陡坡地区蔓延;缓冲区与核心区格局演化呈不合理,缓冲区不但要防止居民点向陡坡地区蔓延,还应合理规划道路、还林还草,提高农用地利用效率;核心区毁林开荒现象较为严重,且农用地利用率低;4)造成格局差异的因素主要包括保护区发展的政策导向、特殊的地理形态以及不合理的土地利用。     

景观湖泊富营养化治理及案例分析研究

景观湖泊的富营养化问题日益严重,其控制和治理,与天然湖泊及传统的污水处理有一定的共性而又存在明显的区别。在分析景观湖泊特点的基础上,综合介绍了湖泊富营养化的主要控制措施。并以4个不同的景观湖泊治理工程为案例,列举采取的措施及取得的效果,进一步探讨景观湖泊治理的要点、存在问题及研究发展方向,为景观湖泊的综合治理提供借鉴。     

城市景观生态建设探讨——以长沙市芙蓉区为例

城市景观生态建设是城市生态规划建设的重要内容。在归纳总结了城市景观生态的特点和规划内容的基础上,以长沙市芙蓉区为例,分析了长沙市芙蓉区景观生态现状,并运用景观生态学原理,对长沙市芙蓉区景观生态建设提出了一些建议和措施,具体包括：景观的生态框架设计,种群源（斑块）工程,廊道与节点工程,城市山水生态工程,城市绿地建设工程和城市景观文化规划。通过上述具体的生态景观规划和建设,使长沙市芙蓉区的景观生态能得到较大改善,更好地为城市生态功能服务。     

城市热岛效应与景观格局相关性研究

城市下垫面的改变和人为热的增加是加剧热岛效应的重要原因,研究城市热岛效应对揭示城市景观的生态过程、城市空间结构的调整都有重要的指导意义,城市热岛效应与景观格局息息相关.遥感、地理信息系统与景观生态学理论共同形成了对大尺度城市空间格局独具特色的研究模式.卫星遥感数据反演法在城市热环境研究中具有举足轻重的地位,它实现了城市热岛效应的动态监测和内部结构分析.城市热岛与景观格局的相关研究往往转化为地表温度与土地覆盖/利用的相关研究,景观格局指数分析法是其重要研究方法,但仍存在界限不清、表现不敏感、生态学意义不明等问题,最后针对此类研究的重点难点提出建议.