水文连通变化下黄河三角洲盐沼植物适应机制与恢复弹性阈值

Coastal saltmarshes provide important resource and ecological functions for the development of coastal cities. However, coastal saltmarshes are suffering serious losses due to the stress from intense anthropogenic activities. The Yellow River Delta has the largest saltmarsh in North China. Coastal saltmarsh wetlands of the Yellow River Delta have lost over 70 % in the last four decades. How to maintain the stability of salt marsh plant community has become an urgent issue in the process of coastal development and protection. Targeting the strategic demands of ecological protection and restoration of coastal saltmarsh wetlands and international academic frontiers about adaptation and resilience of saltmarsh plants, this research focuses on the ecological effects on saltmarsh plant community of altered hydrological connectivity caused by tidal restriction of seawall. Across the whole life cycle of saltmarsh plant species, we will solve the key scientific problem on the persistence and adaptive threshold of plant community. We will use multidisciplinary theory and methods and conduct a series of field observations and manipulation experiments to clarify the adaptive mechanism of saltmarsh plant species in different life cycle stages to environmental stress. In addition, by constructing a dynamic model of saltmarsh plant species, the research identifies the resilience threshold of salt marsh plant species whole life cycle under multi-environmental stresses form alterations of hydrologic connectivity. The research will enhance the understanding of the protection and restoration of coastal saltmarsh wetlands, assist in solving the basic ecological problems faced by the Yellow River Delta, as well as other coastal saltmarsh wetlands in China.

滨海盐沼是海岸带社会经济发展的重要资源和生态安全屏障，但在高强度人类活动影响下损失严重。黄河三角洲作为我国北方盐沼的主要分布区，近40年来，其盐沼植物分布面积已丧失70%以上。如何保护滨海盐沼、维持盐沼植物群落稳定已是该区域亟待解决的重要生态问题。本项目立足于滨海盐沼植物环境适应性与恢复弹性的学术研究热点，面向我国滨海盐沼生态保护与恢复的重要实践需求，针对黄河三角洲盐沼植被退化的实际问题，从堤坝围隔造成潮流阻断引发的水文连通变化入手，以植物全生命周期为视角，聚焦“水文连通变化下盐沼植物能否稳定维持？”的关键科学问题，开展多学科交叉的野外观测和原位控制实验，探讨盐沼植物在生命周期中关键生命阶段对环境胁迫的适应机制，重点突破盐沼植物生命周期整体稳态特征在水文连通变化下的恢复弹性阈值，为解决黄河三角洲面临的基础生态问题提供新思路与新方法，为提高我国滨海盐沼生态保护与修复整体水平做出贡献。

项目针对黄河三角洲盐沼植被退化的实际问题，从堤坝围隔造成潮流阻断引发的水文连通变化入手,在水文连通变化特征、水文连通变化对湿地关键环境要素的影响、水文连通变化对盐沼植物全生命周期的影响和水文连通变化下盐沼植物全生命周期修复模式四个方面进行了研究，任务全部完成，取得了创新性成果。.（1）构建了水文连通强度变化下湿地地貌演化模型，采用连通度指数揭示了近40年来黄河三角洲纵向、横向水文连通度变化规律。.（2）揭示了不同纵向连通结构中水动力扰动对互花米草入侵过程的影响，阐明了人为活动造成的侧向水文连通改变对互花米草入侵的促进机制。.（3）提出了基于水文连通格局的植被恢复策略优化配置模式，构建了盐沼植物全生命周期的生态修复模式。.项目在Global Change Biology，Journal of Applied Ecology，Science of the Total Environment等生态水利主流期刊上发表学术论文13篇。项目主要成果被Global Change Biology、Nature Reviews Earth & Environment、Science of the Total Environment等国际学术期刊正面引用。在SCI刊物Frontiers in Marine Science上出版专刊“Degradation, Ecological Restoration and Adaptive Management of Estuarine Wetlands under Intensifying Global Changes”；SCI刊物Water出版专刊“Ecohyrological processes, environmental effects and integrated regulation of wetland ecosystems”；SCI刊物Sustainability上出版专刊“Frontier Research on Sustainable Coastal Wetland Ecosystem”。授权国际发明专利1项。指导黄河三角洲湿地生态修复实践工程800余亩。通过本项目的实施，协助培养博士毕业生1名，硕士毕业生2名，在读博士生1名。