浮游-底栖层的耦合作用是理解湖泊食物网营养动态的重要能量路径。受季节性水位波动的影响，通江湖泊湿地植物的迁入与迁出会改变湖泊食物网的结构功能和碳源利用途径，然而水体消费者对湿地植物来源的碳利用途径及其营养循环的过程尚不清楚。湿地植物作为重要的外源性碳源被浮游生物利用是间接的，但可以直接被底栖动物摄食利用，并将营养与能量传递到高营养级的水体消费者。因此，本项目假设湿地植物来源的碳源主要通过底栖层为通江湖泊水体消费者提供营养源。拟采用稳定同位素技术与总有机碳、C/N分析相结合，研究季节性的水位波动对通江湖泊——鄱阳湖鱼类与无脊椎动物等物种组成及其碳源利用的影响，进而探讨在水位变化驱动下浮游-底栖层耦合的过程及其生态机制。通过揭示不同水文时期维系通江湖泊的碳源利用及其能量循环过程，将为研究通江湖泊的江湖关系和制定相关生态调控对策提供理论依据。

Pelagic-benthic coupling proves to be one of important energy paths for the understanding of trophic dynamics in lake food webs. Due to the influence of seasonal water-level fluctuation, wetland plants immigrate and emigrate to Yangtze-connected lakes periodically and this can modify the food web structure and function, and the mechanism of carbon utilization in Yangtze-connected lakes. However, little is known about the process of wetland plants-derived carbon utilization by aquatic consumers and its nutrient cycling. Wetland plants, serve as one of important allochthonous carbon sources in Yangtze-connected lakes, can be utilized indirectly by plankton but fed directly by zoobenthos, and ultimately transfer the nutrient and energy source to higher trophic level consumers in Yangtze-connected lakes. So, present study hypothesizes that wetland plant-derived carbon sources provide aquatic consumers with nutrient source primarily through benthic food web in Yangtze-connected lakes. Present study attempts to investigate the impacts of seasonal water-level fluctuation on the species composition, carbon utilization of fish and aquatic invertebrate in Lake Poyang, the largest Yangtze-connected lake in China, through the technique of stable isotopes and the analyses of TOC and C/N, and then ascertain the process and ecological mechanism of pelagic-benthic coupling induced by seasonal water-level fluctuation. Furthermore, we attempt to clarify the mechanism of carbon utilization in Yangtze-connected lakes and the process of energy cycling during different hydrological periods. Our ultimate goal is to provide theoretical guidance for the researches on the relationships between Yangtze River and Yangtze-connected lakes, and the establishment of ecological control countermeasures in Yangtze-connected lakes.