全球升温背景下生物多样性的变化对生态系统功能所产生的影响已成为目前生态学领域关注的焦点问题。微生物因其具有强大的初级生产力，在生态系统乃至全球环境变化中起着关键性的作用。现代生态学中微生物生态方面的研究在时空尺度和变化幅度上均受到很大限制。研究地质历史时期大幅度气候波动期间微生物多样性的变化，可以弥补现代生态学的不足，获取特定时期大幅度和灾难性的微生物多样性变化的重要信息。特别是在地质历史时期一些微生物群落—硅藻，可以保存完整的生物遗存，为研究微生物多样性提供了得天独厚的条件。本项目计划利用末次冰消期三个不同气候带封闭湖泊的微生物硅藻记录，对比分析不同气候带湖泊的硅藻组合、生物多样性对末次冰消期变暖场景响应方式的异同，并探讨其与湖泊生产力之间的关系，尝试性揭示生物多样性与生态系统功能稳定性之间的关系，为认识大幅度快速气候变化过程中微生物多样性的变化规律提供地质历史证据。

The influences of declining biodiversity induced with global warming effect on the functioning of ecosystems have been a focus issue. Microbial community is an essential component in global ecosystems as a result of its high efficiency of primary productivity. They also play a massive role in controlling the global climate. Modern ecological investigation on the contribution of microbial biodiversity to ecosystems is largely limited by the scale and amplitude of biodiversity variations in modern ecological experiments. While, the microbial fossil records in geological records, which can be well preserved in sediment, can compensate the demerits of modern ecological research and provide some information to help us to understand how microbial biodiversity changed with dramatic shifts in climate. This project will explore the changes of diatom composition, biodiversity during the last deglacial from three close lakes which distributed in different climatic zones; this application will aim to assess how diatom biodiversity varies with temperature during the successive warm and cold periods during the last deglacial. The project will explore the relationships between diatom redundance and diatom biodiversity, and finally investigate their influences on the productivity of lake ecosystems. We are hopefully to make a reasonable assessment on the role of biodiversity in the functioning of ecosystems with climate changes.