武汉月湖湿地的管理与生态恢复

城市湖泊湿地是城市重要的生态基础,具有许多生态功能和社会服务功能。合理开发和利用湿地资源是确保城市可持续发展的重要前提。针对武汉月湖的水体污染问题,围绕城市受污染水体的生境改善、生态系统结构优化与系统稳定等问题,开展水生植物定植、湖滨人工湿地、藻类控制、受污染底泥修复等水质改善技术的研究,并相应建设示范工程对月湖湿地进行管理和生态恢复。     

城市湿地管理与恢复

城市湿地是城市重要的生态基础,具有许多生态功能和社会服务功能,合理开发和利用湿地资源是促进城市可持续发展的重要因素。结合国内外有关城市湿地的研究,指出城市湿地的3R管理策略:即鼓励居民积极休闲娱乐、湿地恢复、湿地科学研究。介绍了城市湿地恢复与重建的基础理论以及城市湿地恢复成效评估、评估标准的建立过程。     

Cities within cities: intra-urban comparison of infrastructure in Mumbai,Delhi and Cape Town

Comparison is now taken as vital to the constitution of knowledge about cities and urbanism. However, debate on comparative urbanism has been far more attentive to the merits of comparisons between cities than it has been to the potential and challenges of comparisons within cities—to what we call “Intra-Urban Comparison” (IUC). We argue that a focus on the diverse forms of urbanism located within cities may generate critical knowledge for both intra- and inter-urban comparative projects. IUCs highlight the diversity inherent in the category “city,” revealing dimensions of the urban that are central to how cities work and are experienced. We mobilise fieldwork within three cities: Mumbai, Delhi and Cape Town, and consider both how these cities have been historically understood as different urban worlds within a city, and discuss key findings from IUCs we have conducted on infrastructures. We find that IUCs can enhance comparative work both within and between cities: reconceptualising urban politics; attending to the varied and contradictory trajectories of urban life; and bringing visibility to the diverse routes through which progressive change can occur.     

黄河三角洲芦苇湿地生态修复效果评价研究

基于黄河三角洲芦苇湿地退化现状及所实施的生态修复工程,以正负参照系选取了4块不同修复年限的样地,从湿地生态系统的环境质量、结构与功能的角度构建了湿地修复效果评价指标体系,利用层次分析法确定各指标权重,利用模糊综合评价法对黄河三角洲盐渍化芦苇湿地的修复效果进行定量评价。结果表明:黄河三角洲芦苇湿地4年修复期的样地评价得分为4.01,2年修复期的样地评价得分为3.16,对应评价结果分别为"优"和"良"的等级。相比负向对照,修复区的水体指标和土壤指标参数显著改善,而植被生物量和密度与自然样地还有较大差距,说明生物群落的建立需要更长的时间;同时,湿地水资源管理是该区芦苇湿地生态修复工程的关键,应根据芦苇不同生长期的需水量,制定合理的抽灌制度,达到洗碱脱盐和植被建群的双重目的。     

MANAGING PLACE AND IDENTITY: THE MARIN COAST MIWOK EXPERIENCE

ABSTRACT. Group identity serves as a mechanism for claiming rights of control and access to land in the United States. Public land managers face myriad identity‐based claims to land in their care. Identity shapes claims that must appear valid within the strictures of a legal system created by a dominant culture to serve its interests. The very form of those systems—of which public lands are a large part—makes possible the expression of particular forms of identity. The story of the Coast Miwok community and the Point Reyes National Seashore suggests that geographical links among identity, landscape, and history are actively constructed through political work and rarely are as obvious as they first appear. Both the formal legal process of federal tribal recognition and restoration and the far less formal Coast Miwok claims to land at Point Reyes National Seashore teach important lessons about neotraditional identity‐based claims to public land.     

基于鹭类生境需求的海岸带海陆一体化修复

以泉州湾河口湿地为研究对象,开展海陆一体化修复工程,包括滩涂红树植物种植和互花米草控制、鱼塘改造和退养还湿、海陆交错带植被修复等手段。通过评估植被和生境恢复情况,对比修复前后鹭科鸟类的群落组成变化,探讨滨海湿地修复对鸟类的生态作用和修复的有效性。结果表明:修复工程开展后,滩涂和鱼塘生境得到了改善;海陆交错带植被覆盖率和植被指数NDVI呈上升趋势;研究区内共记录到鹭科鸟类11种18164只次;与修复前相比,修复后第2年鹭类种类和数量均呈现一定程度的下降;修复后第4年鹭类数量显著增加。泉州湾河口湿地修复工程为鹭类提供了更多适宜的栖息环境,对鹭类多样性保护具有重要意义。     

The Politics of Eminent Domain: From False Choices to Community Benefits

Large-scale urban redevelopment projects catalyze moments of peril and opportunity. In the wake of the United States Supreme Court's Kelo v. New London decision affirming economic development as a public use under the takings clause of the Constitution, these perils and opportunities have again become a site of major contestation. An unusual alliance of libertarian property-rights ideologues and civil-rights organizations has joined forces to challenge the use of eminent domain in urban economic development. In this article, I analyze the history of these alliances and their implicit reinforcement of deeply reactionary constructions of property. I conclude with an evaluation of two emergent models—community benefit agreements and community equity shares—that provide promising community tools for alternatives to homeowner rule and neoliberal urban renewal.     

Development of a GIS model to enhance macrophyte re-establishment projects

Diverse native aquatic macrophytes serve a number of physical and biological functions in the aquatic environment and provide essential habitat for several fish species. In systems that lack submersed macrophytes, native macrophyte re-establishment can be used to revitalize the aquatic community. Planning re-establishment projects requires knowledge of the system along with the growth requirements of macrophytes. Prior studies have identified factors that are important for macrophyte colonization, persistence, and dispersal. However, deductive approaches to identify macrophyte habitat that is suitable for management application have not been developed. A potential solution to this problem is the incorporation of waterscape-wide variables into a Geographic Information System (GIS) and the use of spatial modeling techniques to identify suitable macrophyte habitat. This provides a scientifically based approach to macrophyte re-establishment planning to make efforts more efficient and to recognize potential coverage. The flexibility, scalability, and topological advantages of using a GIS to identify and visualize habitat allow integration with other spatial ecological variables to improve the management of aquatic resources from plants to fish, including invasive species mitigation. Using Little Bear Creek Reservoir, Alabama, as an example system, we illustrate a GIS modeling process that can be applied to any system where the identification of macrophyte habitat is relevant to aquatic resource management goals.     

OpenStreetMap and Food Security: A Case Study in the City of Philadelphia

OpenStreetMap (OSM) is an online public access database that allows for the collaborative collection of local geographic information. We employ this mapping technology to discuss a new social theory of poverty that moves away from income poverty to an economy that directly produces individuals' basic needs. Focusing on urban farming in Philadelphia as an example, we use OSM to support the argument that money, land, labor, and capital do not limit food production in the city. OSM is a type of “commons” that allows community members to depict features of interest to them that might otherwise be underrepresented in official or commercially produced maps such as Google Maps. Using the concept of facilitated volunteered geographic information (VGI) we developed an open framework for combining residents' local knowledge of food resources with expert guidance in data input. We believe this helps overcome problems with ad hoc data submission efforts to which collaborative online projects are susceptible. The program for “tagging” food resources in OSM was deployed in a public “map-a-thon” event we organized in Philadelphia, bringing together technical experts and food enthusiasts. To share the results, we present the Philly Fresh Food Map as an interactive online Web map that can be used and updated by the public.     

Research on Ecological Protection and Restoration Measures in Altay Region based on the Coupling Perspective of the Mountains-Rivers-Forests-Farmlands-Lakes-Grasslands System

The adoption of both Nature-based Solutions (NbS) and a system perspective is a hot issue and an area in which there is much room for improvement in ecological protection and restoration. The study takes Altay region as an example, an area located in Xinjiang, China, which is an important ecological corridor of the national key functional area and the core area of the Belt and Road but has a fragile ecological environment and needs much enhancement in ecological protection and restoration. Guided by the concept of “mountains-rivers-forests- farmlands-lakes-grasslands (MRFFLG) system is a life community”, the coupling relationship of the various MRFFLG elements, the main ecological environmental problems and the integrated countermeasures for protection and restoration in Altay region have been analyzed in this study. The study shows that Altay region has a typical meta-ecosystem of mountain, oasis, and desert, and the connections by rivers and lakes make the ecosystem links within the region much closer. The interweaving of resource-environmental-ecological issues of the aquatic ecosystem, degradation of the quality of terrestrial ecosystems such as forests, grasslands and farmlands, the increased ecosystem fragmentation and ecological risks are the major ecological environmental issues in this region. This study takes the improvement of the ecosystem health and function in Altay region as the core goal of regional ecological protection and restoration. First, we establish a zoning governance pattern from the perspective of ecosystem integrity; second, we design governance strategies for different zones with the goal of synergistic improvements in the ecosystem functions; and finally, we clarify the key engineering tasks in different zones from the perspective of ecosystem services. Ecological conservation and restoration of the MRFFLG system is a prime example of the application and development of NbS in China. This paper constructs an analytical framework for identifying regional life communities, diagnosing ecological protection and restoration of zoning problems, and proposing classified solutions for ecological protection tasks for the protection of the MRFFLG system. This research will enrich the theory and technology for the protection and restoration of MRFFLG systems, and provide guidance for the practice of ecological protection and restoration in Altay region.     

基于生物–环境–服务功能模型的三江源高寒草甸湿地不同恢复措施效果评价

研究以青海省三江源区退化草甸湿地为研究区，对湿地环境和功能进行评估，构建了基于生物（Biology）-环境（Environment）-服务功能（Service）的BES模型（涉及3个生物指标，4个环境指标，8种生态系统服务功能指标）评估3种湿地恢复技术（I-补播草种+生长期封育；II-围栏封育和III-防鼠样地）对湿地恢复的效果。基于2017年和2018年的监测数据，计算湿地综合健康指数（Comprehensive healthy index，CHI）和净变动指数（Net variation index，NVI），分析不同恢复措施下湿地健康的恢复过程及其恢复程度。结果表明：① 3种修复技术在湿地恢复中均取得较好的效果。湿地的综合健康指数从2016年未实施任何措施时的0.499分别上升至0.712、0.716和0.650，湿地健康水平由警戒状态恢复至良好状态；② 评价期内恢复技术I和II对湿地恢复效果均好于恢复技术III，但未发现恢复技术I和II之间存在显著差别；③ 高寒湿地生物指标与供给指标恢复速度较快、恢复程度较好，而土壤支持等指标恢复速度较慢、幅度较小。补播草种有助于短时、高效地恢复湿地植被，而实现土壤和功能的全面恢复还需要结合封育等更多的措施和更长的周期。     

滨海湿地红树林生态修复对鹭科鸟类种群动态的影响

通过调查厦门市下潭尾滨海湿地红树林生态修复区的鹭科鸟类物种和数量,对比海水不同潮位鹭科鸟类数量、生境分布以及红树林不同修复阶段白鹭种群数量变化,探讨红树林生态修复对鹭科鸟类种群动态的影响。2018—2019年在修复区共调查记录到8种鹭科鸟类,秋冬季鹭鸟种类较多,5—6月鹭鸟数量最多,其中白鹭为优势种;与修复初期相比,修复区在修复完成后的白鹭种群数量明显增加;修复区鹭科鸟类在海水低潮位时主要觅食于潮间带滩涂,在高潮位时大多数停歇于未被海水淹没的红树林,观察发现一些鹭鸟在繁殖季节营巢于高大的红树林。结果表明,滨海湿地红树林生态修复能够改善鹭科鸟类栖息环境,增加修复区的鹭科鸟类数量。     

城市湿地特征及其生态恢复

通过对城市湿地功能和特征以及城市化进程中城市湿地面积缩减、水质污染及功能退化等问题的分析,揭示城市湿地退化的主要原因,依据结构决定功能的生态学原理,提出湿地退化恢复的实质是结构的修复,城市湿地的恢复应采取汇水区水源保护、汇水净化治理、入湖河流截污、河道修复及重建湖滨结构的城市湿地恢复策略。     

Enhancing the effectiveness of policy-relevant integrative research in rural areas

There has been much debate about the importance of policy-relevant research in geography over the last decade. There has also been an increasing recognition by policymakers of the importance of integrative (interdisciplinary and transdisciplinary) approaches to policy-relevant research. However, geographers have been more reluctant than their colleagues in other social and natural sciences to embrace integrative research collaborations. For integrative research to achieve its full potential and to encourage greater participation from the geographical research community, we need to increase our understanding of its potential value, but also some of the challenges that it poses, and how these can be overcome. In this paper, we consider the processes involved in conducting successful integrative research from the perspective of researchers involved in these projects. We base our analysis on the results of a questionnaire survey of international integrative research programmes on environmental issues in rural areas, combined with our own experiences of working in integrative research. We conclude that effective integrative research depends on the establishment of a clear conceptual framework, the use of appropriate temporal and spatial scales in the research, effective language and communication, time and commitment, and trust and respect. We also highlight the value of stakeholder involvement in integrative research to ensure the policy relevance of the work and provide a mechanism to assist with effective knowledge transfer of the results.     

Configuring growth coalitions among the projects of urban aggrandizement in Kunming,Southwest China

In this paper, we examine two urban projects in Kunming, Southwest China, one a massive scheme to build a new city center on rural land outside the city, and the other, an act of urban restructuring involving the rebuilding of an old Hui (Muslim) neighborhood in the old city center. We analyze the coalition of forces configured to undertake these large-scale projects; we underline the role of specially formed city-building organizations and the support provided by the state-owned institutions that dominate the city’s political economy; and we draw attention to the caution with which the city government handled resistance to urban restructuring among Hui residents. We argue that urban growth projects in inland cities like Kunming are marked by certain features that distinguish them from similar projects in Eastern Chinese cities but maintain that nonetheless the drive for profit maximization at the expense of residents is unchanged.     

Legacies of a Contested Campus: Urban Renewal,Community Resistance,and the Origins of Gentrification in Denver

The postwar urban renewal experience varied among US cities according to the result of local social contests pitting those imposing their power to transform urban space against those resisting it. In this paper, we examine the role of one such contest in shaping urban renewal outcomes in Denver, using the case of the late 1960s Auraria project. The project sought to remove a poor, Hispanic neighborhood in order to build a new downtown college campus, generating community opposition from the inner city neighborhood residents, leaders of the city’s Chicano Movement, and historic preservation activists. We demonstrate how resistance actively shaped the ultimate form and character of the project, and how the legacies of this urban renewal contest extended—in unforeseen ways—beyond the immediate struggles of the time. We argue that these legacies provide the essential context for understanding planning practice, redevelopment strategies, and gentrification dynamics in the city today.     

基于光谱混合分解的民勤生态治理效果评价

作为退化绿洲典型,甘肃民勤生态治理效果的评价对全球干旱区土地退化防治具有重要借鉴作用。使用Landsat系列遥感数据,基于光谱混合分解模型,采用土地覆被/利用分类后比较和端元丰度值差值的方法,对民勤生态工程第二阶段初期(2010—2015年)的治理效果进行了定性和定量研究。结果表明:民勤县土地退化面积为39 712.14hm^2,恢复面积为101 503.44hm^2,恢复面积大于退化面积,呈现出恢复的态势。沙地面积减少,沙地的沙化程度降低;盐碱地面积虽有增加,但盐碱地的盐渍化程度有所下降;林草地相较耕地、夏作耕地相较春作耕地成为当地优势植被地类;水域面积虽有减少,但水域的水含量有所增加。民勤经过近20年的生态修复治理,已经进入良性修复阶段。     

Environmental justice in urban greening for subtropical Asian cities: the view from Taipei

Whilst an extensive body of literature exists on the environmental justice implications of urban greening in North America, Europe and to an extent Australasia, there are fewer analogous studies for tropical zone Asian city contexts. Given increasing global interest in the potential for urban greenspace to contribute to resilience in the face of environmental change and the higher vulnerability of Asian cities to environmental shocks, this is a notable gap. In response, this paper evaluates the contours of environmental justice debates within urban greenspace planning for one subtropical Asian city—Taipei. Through analysis of newspaper reporting on urban greenspace planning within Taipei, the potential and limitations of greenspace planning in contributing to equitably delivering benefits from urban greenspace towards resilience are assessed. Findings suggest that claims to environmental injustice in greenspace debates within Taipei follow broadly similar lines to controversies in Europe and North America. Nevertheless, the need for specific knowledge to understand the different ecosystem services provided by tropical zone ecosystems, and the potential for conflicts over greenspace versus development to be heightened in dense Asian city settings, are highlighted as potential areas where environmental justice debates in an Asian urban greening context may differ from Western cities.     

Systematic Inquiry into Barriers to Researcher Access: Evidence from a Homeless Shelter*

Geographers using qualitative methods face numerous challenges, including barriers to access to the research setting that emerge through the interactions among the researcher's identity, participants, and the research setting itself. However, few geographers have systematically traced, within a single research setting, (1) how barriers originate, (2) how they subsequently complicate the research enterprise, and (3) how they may potentially be overcome. Upon defining various generic barriers to access, I focus on the origins of, encounters with, and potential strategies to overcome two barriers (factions and spatiotemporal limits) during my research experiences at the Palms Mission, an emergency shelter in Central Los Angeles. Ultimately, understanding the negotiation of these barriers informs the broader research process.     

景观演化特征指数及其应用

随着中国城市化建设的快速推进,城市蔓延式增长和生态空间持续性萎缩成为普遍的现象,以地表硬化为主要特征的城市景观格局变化得到广泛关注,而景观扩张指数(Landscape Expansion Index, LEI)是测度这一现象的重要工具。但在新型城镇化背景下,由于大城市空间结构调整优化以及城市绿化率的提高,硬化地景观的收缩与消亡已成为城市景观演变的另一重要形式,因此亟需新的有效手段来刻画城市发展的新特征。在此背景下,本文在LEI指数的基础上,提出景观演化特征指数(Landscape Evolution Characteristic Index, LECI),尝试综合描述城镇化过程中硬化地景观斑块扩张与收缩的动态特征;并基于邻域特征计算的景观演化特征指数,包括景观演化模式识别指数(Landscape Evolution Pattern Index, LEPI)和景观演化规模指数(Landscape Evolution Area Index, LEAI),协同分析两个或多个时相景观格局演变过程中的斑块新生与消亡。本文将LECI指数应用于武汉都市发展区1990-2010年期间的城市硬化地景观演变过程中,与基于最小包围盒的景观扩张指数(LEI)对比分析,结果表明：①LEPI能准确识别不同规模和形状斑块的空间扩张模式,LEAI能够较好反映斑块扩张强度并表征景观扩张方向;②LEPI能有效识别城市景观演变中消亡斑块的湮灭模式,研究区内硬化地景观消亡现象明显加剧,可能与政府加强城市内部改造及绿化建设有关;③LECI指数变化分析发现,武汉都市发展区研究期内的城市景观扩张强度有所放缓,飞地式和边缘式空间增长构成斑块演变的主体,城市硬化地景观扩张模式在空间上呈现明显的梯度分异规律,随距主城区的远近呈现填充式/包围式、边缘式/邻接式到飞地式/孤立式的演替。