云南程海沉积古DNA和色素记录的近千年浮游植物群落演替历史及其驱动机制研究

浮游植物是湖泊生态系统健康状况的重要指示器，其群落演替过程反映了湖泊生态环境动态变化历史。由于长期监测数据缺失以及传统古湖沼学指标的局限性，使得长时间尺度下有效反演浮游植物群落演替过程及其驱动要素量化研究尚有不足，限制了湖泊水环境治理与生态修复可持续发展理论的完善。本项目以云贵高原典型湖泊-程海湖为研究对象，首先采用分子生物技术和高效液相色谱法分析季节性水体、表层沉积物中DNA和色素反映的浮游植物（真核藻类和蓝藻）信息，提取能够表征藻类组成的有效DNA和色素指标并建立本地浮游植物基因数据库；然后在沉积柱精确定年基础上，利用古DNA和色素指标有效重建近千年浮游植物多样性、丰度和物种组成；最后结合沉积物多环境代用指标以及区域气候和人类活动等记录分析，运用多种统计模型（半）定量阐释浮游植物群落演变的驱动机制。本研究结果可为程海湖水质改善和生态修复提供科技支撑。

Phytoplankton community structure and succession is the indicator of lake ecological environment change. However, due to the lack of long-term monitoring data and the limitation of traditional palaeolimnology indicators, there are still insufficient studies on how to effectively reconstruct phytoplankton community succession and quantitatively interpret their driving mechanism at a longer time scale. It restricts to complete the theory of lake environment management and ecological restoration. In this project, a typical eutrophication deep lake Chenghai will be selected as the research object. We will analyze phytoplankton DNA and pigments in both water and surface sediments by molecular biological methods and high performance liquid chromatography (HPLC) respectively, to evaluate the preservation status and representativeness of DNA and pigments in lacustrine sediments. Furthermore, based on the ancient DNA and pigment records from the long sediment core, the phytoplankton diversity, abundance, and community structure over the past 1000 years will be reconstructed effectively. Combined analysis of multiple environment indexes in the sediment core and regional climate/human activity records, the statistical models and numerical simulations will be used to explain the share of phytoplankton succession driven by various environmental factors. This study can provide scientific support for lake water quality improvement and ecology repair.