作 者 ：李晓文,郑钰,赵振坤,黎聪
期 刊 ：生态学报 2007年 27卷 12期 页码：4979~4989
关键词：长江中游生态区；湿地水禽；潜在生境；Gap分析；保护网络；
Keywords:Central Yangtze Ecoregion, habitat suitability unit, potential habitats, gap analysis, conservation network,
摘 要 ：构建了综合反映长江中游生态区地形、植被与地表覆盖特征的GIS综合空间数据库，在对长江中游生态区核心湿地保护物种，即白鹤(Grus leucogeranus)、东方白鹳(Ciconia boyciana)、小白额雁(Anser erythropus)、中华秋沙鸭(Mergus squamatus)分布范围和生境需求分析基础上，建立了反映物种分布与GIS数据库中生态地理因子关联的生境适宜性单元，从而确定了核心物种分布的潜在生境，对照现有保护区分布格局，找到了区域湿地生境保护的薄弱和空缺区域(Gaps)，评价了现有保护区系统对潜在生境保护的有效性。基于Gap分析结果和现有保护区分布格局，进一步考虑保护网络的整体性和连通性以及保护成本，构建了长江中游湿地保护区生物保护网络的合理格局。研究结果表明：长江中游生态区核心物种潜在生境涉及134个县（市）级单元，而目前长江中游湿地保护网络仅覆盖了23.49%的潜在生境，仍有大量潜在生境游离于现有保护区系统外。为完善长江中游生态区湿地保护网络，应在湖北（13县）、安徽（8县）和江西（1县）所属22个县域内建立新的湿地保护区或保护小区，并与现有湿地保护系统有机整合，最终才能形成较为完善的由45个县级单元构成的的长江中游生态区湿地生物保护网络合理格局，并保护80%以上核心物种的潜在生境。本研究同时也表明基于GIS生态地理空间数据库和生境适宜性单元概念进行大尺度生境分析具有一定可行性和应用价值。
Abstract:Due to the vast wetlands and associated rich biodiversity, Central Yangtze river and its lakes basin (i.e. Central Yangtze Ecoregion) is designated by WWF as one of the Global 200 Ecoregions that contains a distinct assemblage of natural communities sharing a large majority of species, dynamics, and environmental conditions, and effectively functioning as a conservation unit. However, in the past half century the wetlands in the Central Yangtze and the biodiversity they support have suffered from constant threats, mostly associated with human activities, such as large-scale agricultural practices, land reclamation, water projects building and rapid urbanization, etc. This article therefore aimed at establishing and optimizing ecological network for wetland conservation in the Central Yangtze Ecoregion based on Gap analysis. To conduct Gap analysis, a comprehensive spatial dataset was established based on different factor combinations of landform, vegetation and landcover types, and the habitat suitability classes were defined with the analysis on the distribution area and habitat requirements of focal waterbirds (i.e. Grus leucogeranus, Ciconia boyciana, Anser erythropus and Mergus squamatus) in the Central Yangtze Ecoregion. Habitat suitability unit was used to identify regional potential habitats through spatial extrapolation with GIS dataset in which a spatial linkage between the species distribution and main eco-geographic factors were built. Comparing the potential habitats with existing distribution of wetland nature reserve in the Central Yangtze Ecoregion, the Gaps (i.e hotspots of species while not included in the existing conservation system) of wetland conservation in the Central Yangtze Ecoregion were located, and conservation efficacy of existing conservation system thus was evaluated. Given the integrity and connectivity of existing conservation system, an optimized wetland conservation network was finally developed from the Gap analysis and spatial patterns of existing conservation network. The results showed that, the potential habitats of focal species cover 134 counties in the Central Yangtze Ecoregion, but only 23.5% of the total area of the potential habitat has been included into the existing conservation system in 23 counties. Lots of potential habitats are still directly exposed to the human impacts. To improve and optimize the spatial pattern of existing wetland conservation system in the Central Yangtze Ecoregion, it is necessary to establish new wetland nature reserves in 22 counties across Hubei (15counties), Anhui (9 counties) and Jiangxi (1county) provinces. These proposed protected areas should be well integrated with existing conservation system, thus it can form a larger and optimized conservation network system composed of 45 counties and provide an effective wetland conservation system in the Central Yangtze Ecoregion. The results also demonstrated that it would be applicable to introduce concept of Habitat Suitability Unit (HSU) in macro-scale habitat analysis with assistance of GIS-based eco-geographic dataset.
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