中国湿地保护空缺分析及其保护格局优化研究

Wetland ecosystems provide considerable amount of the Earth's global biodiversity and substantial ecosystem services, creating a strong imperative for their protection and restoration. Although this unique ecosystem has been exposed to higher pressures and threats than adjacent terrestrial ecosystems, wetland ecosystem has received less attention than terrestrial in its conservation planning and assessment, or mostly protected within framework of terrestrial conservation planning, ignoring fundamental difference between terrestrial and wetland ecosystem, therefore specific consideration of the conservation requirements of wetland ecosystem is needed. In China, wetland conservation has achieved a great progress in the past two decades, 92 national nature reserves and 41 Ramsar sites have been established and incorporated into wetland conservation system, along with numerous wetland nature reserves in provincial and local levels, however some revelant research have revealed that there still exist gaps with high conservation value but lacking protection from current wetland conservation system at regional scale (e.g. upper and central Yangtze River Basin, North China Plain), and the conservation pattern and efficacy of wetland ecosystem also needed to be improved in these regions. This project aims to explore an integrated conservation strategy specifically suited for wetland ecosystem at large river basin and national scale. The wetland conservation strategy will incorporate riverine and nonriverine wetlands into conservation targets, and integrate longitudinal (upstream-downstream), lateral (riverine-floodplain) connectivity into conservation assessment. The climatic and topographic factors will be combined with wetland types to develop wetland ecotopes, which will be employed as large-scale conservation surrogates in conservation planning due to their unique eco-hydrological process and biodiversity assemblages. A national-scale wetland conservation strategy will be explored by innovatively applying approaches well developed for terrestrial ecosystems in the past decade, e.g. systematic conservation planning and its tool-Marxan, which can identify biodiversity priorities and developing conservation strategies in an efficient and defensible manner with complementarity- based planning framework. This project will highlight the need for specific refinements to wetland conservation framework and provide a large-scale wetland conservation framework at national scale, and enable central government and managers of wetland resources to set ecologically meaningful spatial conservation priorities.

系统保护规划作为生物多样性保护规划的新范式，目前主要应用于陆域生态系统，湿地保护实践迫切需要建立适用于流域湿地保护规划的理论和方法。中国湿地保护体系目前也面临着保护效率低下，保护格局亟待优化，湿地保护投入的优先区域确定缺乏科学论证等问题。本项目针对宏观尺度湿地格局与过程保护这一核心科学问题，运用系统保护规划的理论方法，通过反映气候-地貌特征的湿地生态地理综合分类体系及流域连续性保护目标的确立，建立湿地物种、湿地生态系统及其流域生态过程等多层次保护目标，依托空间决策优化模型，考虑流域湿地保护价值的不可替代性和保护成本识别潜在保护空缺，确定中国湿地合理的保护水平及优先保护格局，据此对现有湿地保护体系进行优化。本项目研究既立足于国际保护生物学前沿领域，又契合了现阶段我国湿地保护体系建设的宏观战略需求，结合中国的案例也将进一步丰富发展国际系统保护规划的理论和方法。

我国是全球湿地资源极为丰富的国家，但不少具备较高生态价值的湿地资源仍未纳入国家湿地保护体系，成为易受人为活动干扰威胁的保护空缺。本项目依托GIS/RS手段，借助国际上主流的系统保护规划方法，在区域-流域-国家等不同尺度上对我国湿地资源保护状况、保护空缺和优先保护格局进行了分析和评估。其中，在以黄淮海为代表区域尺度上，整合物种生境、河流与非河流湿地生态系统为保护目标，考虑流域内纵向（上下游）、横向（河流与集水区）和垂向（地表水与地下水）以及流域间通过南水北调工程形成的跨流域水文连接性，构建了黄淮海跨流域湿地生物多样性优先保护格局，进一步考虑地表径流、地表水调节、固碳和生境支撑等四种主要湿地生态系统服务功能，运用InVEST和Marxan优化模型建立了黄淮海地区生态系统服务功能优先保护格局，在对区域湿地生物多样性与生态系统服务热点区域和优化格局的空间耦合效应分析基础上，探索了同时耦合、优化湿地生物多样性和生态系统服务功能优先保护格局的可能性。在流域-国家尺度上，首先依托遥感和地理信息技术，对全国十大流域（水资源分区）所属国家级湿地保护区内湿地面积、生境破碎化指数和生态风险变化趋势进行了定量分析，并藉此对主要流域的湿地保护状况进行了快速评估；通过构建反映气候-地貌分异的湿地生态地理综合分类单元作为宏观尺度生态系统水平保护目标，并考虑流域单元上下游过程的连续性并权衡保护格局优化的社会经济代价，运用的Marxan规划工具，确定了我国主要流域湿地保护的不可替代性格局，识别并确定了各流域湿地保护空缺以及受胁严重的优先保护区域；同时，重点针对长江、黄河和海河等流域湿地保护格局优化结果，提出了较为详尽的湿地保护格局优化策略。本项目成果可望为我国流域湿地保护规划、湿地保护红线的划定以及湿地保护体系空间优化策略提供理论和方法支撑。