众多的生态系统"稳态转换"现象具有不可逆性、不易察觉性及巨大的破坏性，如浅水湖泊由"草型"向"藻型"湖泊的状态转换，近年来受到了国际社会的广泛关注。由于长期生态监测记录的普遍缺乏及驱动要素的复杂性，对浅水湖泊生态系统的转换过程及其触发机制的认识亟待深入。本项目拟通过长江中下游3个典型湖泊沉积记录的多古生态指标和环境代用指标的高分辨率分析，揭示近200年来湖泊生态系统长期变化的过程。考察生态系统是否以及如何发生稳态转换，研究转换前后生物种群和群落结构的变化特征，以及稳态转换发生的主要环境阈值。开展各生物之间、生物与环境之间的关系研究，探讨系统内部反馈过程及生态系统发生稳态转换的驱动机制。本项目从生态演化的视角来揭示浅水湖泊生态系统稳态转换过程及驱动机制，有望进一步丰富湖沼生态学理论，亦可为湖泊生态恢复策略的制定提供重要的科学支撑。

Ecosystem regime shifts often occur irreversibly, unnoticeably and destructively. This kind of ecological pheromone, for instance, the alternative stable states in shallow lakes, has been widely envisaged. Due to the lack of long-term monitoring records and the complexity of the process, it is crucial to obtain a better understanding on the process and mechanism of regime shift in such shallow lakes. This project will reveal the ecological process of three typical shallow lakes along the middle and lower reaches of Yangtze River over the last 200 years. These records will be used to justify whether there exists regime shifts and, if exist, to elucidate the changing patterns and feedback in/between environmental and biological components. The driving mechanism of regime shifts in each lake and in the regional scale will be explored. This work should provide an essential contribution to the ecological theory "regime shift"and important scientific support to the Yangtze shallow lakes'restoration.