黄河三角洲湿地灌丛化群落水分利用规律及其与水位-盐分时空动态定量研究

湿地灌丛化群落（灌木+草地）相较于单一草地，植被有更发达的根系和更强的生存能力，这使其能在地下水埋深浅、土壤盐渍程度高的北方滨海湿地大面积分布。但是，由于灌丛化群落水分利用规律及其与多变水位-盐分环境之间的响应关系不明确，导致其较高的耗水需求与有限的淡水资源之间矛盾突出，制约了湿地生态补水策略的合理制定，威胁了滨海湿地生态安全。基于此，本研究以黄河三角洲盐地碱蓬-柽柳湿地灌丛化群落为研究对象，拟通过野外样带调查和原位监测，探明盐地碱蓬和柽柳在不同水位-盐分环境的生长状况和根系分布特征，厘清湿地灌丛化群落在生长季内的蒸腾耗水规律，并通过同位素技术明确根系在不同水文地质条件下的耗水土层及其水分来源，在此基础上，结合模型揭示植被耗水规律与水位-盐分变化的定量关系。本研究将丰富湿地灌丛化群落植被应对水盐胁迫的理论知识，对于健全黄河三角洲湿地生态补水机制、维持滨海湿地生态系统的健康和稳定有重要意义。

Compared with grassland ecosystem vegetation, Wetland shrub-encroached grassland (WSEG) has more developed roots and stronger viability, which enables it to be widely distributed in northern coastal wetlands with shallow groundwater depth and high soil salinity. However, due to the unclear water use of WSEG and its response to the variable water level-salt environment, the contradiction between its high water consumption demand and limited freshwater resources is prominent, which restricts the reasonable formulation of wetland ecological water supplement strategy and threatens the coastal wetland ecological security. Thus in this project, the quantitative relationship between vegetation water consumption and the change of groundwater level and salt content will be revealed based on the results of the features of root distribution under different water level-salt environment, the dynamic variations in WSEG water use during growth season and the contributions from different water sources combining with water isotope analysis by investigating and monitoring the WSEG, which included Suaeda salsa (L.) Pall and Tamarix chinensis in Yellow River Delta. This study will enrich the theoretical knowledge of WSEG in response to water and salt stress. Besides, it is of great significance for improving the ecological water supply mechanism of wetland in the Yellow River Delta and maintaining the health and stability of coastal wetland ecosystem.