过去200年来太湖流域湖泊生态系统演化与稳态转换研究

Regime shift often results in large, abrupt, and persistent changes in the provision of ecosystem services and can therefore have significant impacts on human wellbeing. Understanding regime shifts has profound implications for ecosystem recovery and management. However, regime shift research is always hampered by the lack of long term series data. In this proposed project, we will take a historical approach to understand how and why lake ecosystem regime shifts happened in Tai lake catchments systems. First, we will reconstruct the long term ecosystem change by analyzing multiple proxies from sediment of three typical lakes, namely Changdang Lake, Tai lake and Cheng Lake. Then we will analysis regime shift based on long term trajectories of ecosystem change, identify threshold and early warning signals by using multiple statistical approaches. Finally, we will compare the dynamic attributes of three lake ecosystems during the last 200 years to reveal the patterns and mechanism of regime shift in the region, and also to understand how climate change and human activities has pushed the lake ecosystem into alternative stable state. This research will generate new knowledge and understanding for Lake Ecosystem restoration and management.

本项目瞄准全球环境变化及生态系统稳态转换研究的学科前沿和瓶颈问题，选择太湖流域湖泊生态系统为研究对象，从历史演变的角度，系统分析太湖流域过去200年来的典型湖泊生态系统演化过程和稳态转换。通过3个典型湖泊（太湖、长荡湖、澄湖）钻孔沉积物多指标分析，结合太湖野外长期监测数据，利用多种数理统计方法，重建过去200年来不同生物群落与环境演化序列，揭示流域内湖泊生态系统稳态转换的动态过程、提取系统发生稳态转换的临界点和早期预警信号。在此基础上，系统分析并对比区域湖泊生态系统响应特征的异同，阐明气候变化和人类活动共同驱动下，流域内湖泊稳态转换发生的机制。该研究将进一步丰富生态系统稳态转换理论，为湖泊生态环境的治理提供新的视角和科学依据。

科学评估生态系统发生稳态转换的关键过程、胁迫因素和驱动机制，已成为目前未来地球计划 （Future Earth）等全球环境变化相关科研组织关注的重要研究。该项目从历史演变的角度，系统分析太湖流域过去200年来的典型湖泊生态系统演化过程和稳态转换。主要取得以下三个方面成果：（1）通过3个典型湖泊（太湖、长荡湖、澄湖）钻孔沉积物多指标分析，系统重建过去200年来湖泊大型水生植被、枝角类、藻类等不同生物群落与环境演化序列。（2）基于多种统计方法，揭示出流域内湖泊生态系统稳态转换动态特征，包括阈值及早期预警信号等，归纳出了我国不同湖泊生态系统发生的时间、规律及差异。系统分析并对比区域湖泊生态系统响应特征的异同，阐明气候变化和人类活动共同驱动下，流域内湖泊稳态转换发生的机制。（3）揭示过去百年太湖流域湖泊生态系统服务的演变轨迹、风险和动力学特征，探讨社会系统和生态系统的协同演化。该研究为湖泊生态环境的治理提供新的视角和科学依据。