作 者 ：胡望舒,王思思,李迪华*
期 刊 ：生态学报 2010年 30卷 16期 页码：4266~4276
Keywords:biological conservation, focal species, landscape security patterns, GIS, Beijing,
摘 要 ：快速城市化进程中，城市及周边地区生物栖息地的丧失和破碎化对生物多样性保护构成严重威胁。如何在景观尺度上判别对于生物保护具有重要意义的栖息地及其空间格局成为了重要问题。选取快速城市化的典型地区——北京市作为研究对象，将焦点物种和景观安全格局方法相结合，对北京市生物保护安全格局进行判别和规划。根据焦点物种的定义和选取标准，将在栖息地类型、生物学特征等各方面具有代表性的大白鹭（Casmerodius albus）、绿头鸭（Anas platyrhynchos）、环颈雉（Phasianus colchicus）选作北京市的焦点物种，应用最小阻力模型和GIS空间分析技术，对焦点物种的栖息地适宜性进行分析，并建立物种运动的等阻力面，根据阻力面的空间特征对北京市生物保护安全格局进行规划。结果显示：规划后的安全格局的斑块数量、分离度、邻近距离显著下降，平均斑块面积和最大斑块指数显著上升；该格局用约60%的土地，保护了北京市主要生境类型及关键性空间格局，可有效缓解栖息地丧失和破碎化的问题，从而达到保护整体生物多样性的目的。这一研究方法和成果可为北京市生物多样性保护和城乡生态建设提供决策依据，也对同类研究具有借鉴价值。
Abstract:Along with rapid economic growth and urban sprawl in China, biological conservation and biodiversity loss in and around cities has become an increasingly important topic for discussion, especially in rapidly urbanizing regions. One of the most urgent threats faced by growing cities is habitat loss, degradation and fragmentation. Focused on this threat, this paper distinguishes the significant habitats and spatial patterns that are of vital importance to biological process and conservation at the landscape scale using Lambeck′s (1997) Focal Species Approach which selects the most sensitive species to a certain threat, whose requirements are believed to encapsulate the needs of other species. The paper also applies Yu′s (1996) Security Pattern Theory which identifies landscape areas and elements of critical significance in safeguarding the process of species maintenance and dispersal. Beijing is an ideal region for employing these approaches and theories because of its: high percentage of urbanized land (84.9% in 2008); corresponding loss and fragmentation of habitats, rapid population increase; and abundant bird species. According to the definition of focal species and a set of specific criteria, Large egret (Casmerodius albus), mallard (Anas platyrhynchos), and ring-necked pheasant (Phasianus colchicus) were chosen as focal species for Beijing among hundreds of candidate species, mainly because of their varied biological characteristics, and the threatened typical habitat types they represent, which are assumed to represent most of the habitats in the whole region. With the aid of a geographic information system (GIS) spatial analysis model, security patterns for individual species were defined as follows: Step 1: a vertical habitat suitability analysis in which the optimum areas for species were selected as the movement sources, and Step 2: a movement resistance surface analysis, which was executed by simulating the horizontal movement across the landscape of the species, through the Minimum Cumulative Resistance (MCR) model. These three individual patterns were considered of equal importance, and were overlaid into a comprehensive biological conservation security pattern with three different security levels to “defend” different conservation situations. A comprehensive biological conservation security pattern plan and relative conservation strategies for Beijing were proposed, including the conservation cores, buffer zones, inter-source linkages and strategic points. This plan is based on the spatial character of the calculated resistance surfaces and general principles in biological conservation. The result showed that, the security pattern plan has a significant decrease in Patch Number (-45.05%), Landscape Division Index (-82.71%) and Mean Euclidean Nearest Neighbor Distance Distribution (-14.51%), as well as a significant increase in Mean Patch Area (85.36%) and Largest Patch Index (45.40%), with only 1.03% increase in total area, which finds that the plan can protect core habitats and critical spatial patterns in Beijing by covering about 60% of the total land. This research concludes that the Security Plan can effectively relieve habitat loss, degradation and fragmentation, and thus support the goal of protecting biodiversity in the whole region. The methods and results, which possess both theoretical and practical value, could provide a defensible decision-making basis for biodiversity conservation and ecological construction in Beijing, as well as for similar research in rapidly urbanizing areas.
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