草-藻型湖泊稳态转换过程中微生物群落稳定性的演化机制

The decreased stability impairs the resilience and resistance of lacustrine ecosystem, leading to the regime shift from macrophyte to phytoplankton dominance. In this scenario, it is scientific and practical significance to illuminate the ecological stability and their driving mechanisms. Due to the ecological complexity, the microbial organisms will be selected as the representatives of lake ecosystems. Based on the microbial succession during the regime shift, exploring the microbial stability could further provide new insight into the lake abrupt changes in the view of microbial ecology. In this project, the aquatic microbial communities of different regions in Taihu Lake will be selected. 1) In order to investigate the spatiotemporal patterns of the microbial stability in different steady states, we will quantify their diversity, interspecific interactions as well as nestedness. 2) In order to illuminate the responses of the microbial stability to the regime shift, we will track the change processes of microbial succession within the simulating regime shift under stresses of eutrophication and phytoplankton. 3) On the basis of the above studies, the microbial stability index will be constructed by random forest model. Combined with environmental factors, we will illuminate the underlying mechanisms of the microbial stability during the regime shift.

湖泊稳定性下降导致湖泊生态系统恢复力和抵抗力变弱，使得大量草型湖泊向藻型湖泊转换。因此，揭示湖泊生态系统稳定性的特征及其驱动机制具有科学意义和现实应用价值。由于生态系统的复杂性，选择具有生态指示意义的微生物作为代表, 以湖泊稳态转化过程作为切入点，通过研究微生物群落稳定性的演化过程，为从微观尺度上进一步揭示湖泊稳态转化过程及其驱动机制提供新的视角。本项目拟选择太湖水体微生物作为研究对象，1）通过研究微生物群落的物种多样性、功能多样性、种间关系及嵌套性，揭示微生物群落稳定性在不同湖区中的时空分异特征；2）通过模拟在营养盐负荷和浮游藻类双重胁迫下湖泊稳态转换过程，结合微生物群落稳定性的变化规律，揭示微生物群落稳定性在湖泊稳态转化中的响应过程； 3）在上述研究的基础上，利用随机森林模型构建稳定性指标，结合生态环境特征，阐明稳态转换过程中微生物群落稳定性的演化机制。