中文摘要：

水生植被是浅水湖泊生态系统最重要的生态特征之一,了解其群落历史演化特征,对生态退化湖泊的修复有着重要指导意义。研究选择长江中下游地区代表性草型湖泊梁子湖,基于梁子湖沉积岩芯210Pb/137Cs测年、沉积硅藻序列和梁子湖长期水生植被监测记录,探讨利用沉积硅藻记录来重建该湖历史时期水生植被演替特征的可行性。研究结果表明:梁子湖沉积硅藻记录对历史时期水生植被的演替有较好的反映;基于此,对梁子湖过去近200年的水生植被覆盖度进行了重建;与湖泊流域历史环境信息的对比分析表明洪水是影响该湖水生植被发育的一个重要因素。研究结果证实了在浅水湖泊中,沉积硅藻可揭示历史水生植被的信息,并为该湖的水生植被保护提供科学依据,同时对该区富营养湖泊的生态修复有重要的指导价值。

英文摘要：

Aquatic vegetation is one of the most important ecological characteristics of shallow lake ecosystems. Un-derstanding its evolution is crucial for lake ecological restoration. In this study, Liangzi Lake, a representative lake from the Yangtze floodplain, was chosen because of the high abundance of aquatic vegetation. To reconstruct the historical evolution of aquatic vegetation, a sediment core from its deepest area was analyzed with radiometric dating (210Pb/137Cs) and sedimentary diatoms. The reconstructed aquatic vegetation information by sedimentary diatom records reflected the succession of aquatic vegetation in historical period in comparison with the monitoring aquatic vegetation records since 1950s. We also reconstructed the coverage of aquatic vegetation over the past 200 years for Liangzi Lake. Based on the data from reconstructed historical aquatic vegetation information and the historical environmental data from its catch-ment, this study revealed that flood was one of the main factors affecting aquatic vegetation development in Liangzi Lake. This study demonstrated that diatoms can be used for the reconstruction of the amount of historical aquatic vege-tation in such shallow lakes, which can provide the scientific basis for the aquatic vegetation protection and important guidance of the lake for the ecological restoration.