扩散限制受到了微生物生态学家的极大关注。微生物是否受到扩散限制是微生物多样性分布模型、群落构建机制以及微生物生物地理学研究中的核心问题之一。但是，这个问题的研究结果并不统一，我们认为这是由于没有考虑到微生物扩散限制的尺度依赖性。本项目拟探究微生物扩散限制的尺度依赖性问题。以收集空气颗粒富集物的方式获得区域微生物物种库，并在实验区域选择环境条件不同且微生物组成不同的水体样品，开展水体微宇宙培养实验。用高通量测序技术检测微生物群落组成、α多样性和β 多样性。在小尺度上研究群落在微生物自然迁入速率下是否受到扩散限制，探究扩散强度如何影响环境过滤和漂变过程；在大尺度上判断微生物是否表现出“物种库扩散限制”。研究结果可以探索微生物扩散限制是否具有尺度依赖性，阐明微生物群落构建机制，为微生物生态学基础理论提供实验验证。

Microbial ecologists have paid great attention to the importance of dispersal limitation. One of the core problems for the studies of microbial diversity distribution model, community assembly mechanisms and microbial biogeography is whether microorganisms suffer from dispersal limitation. However, many studies have shown different results. The possible reason is the studies didn’t consider spatial scale dependence of dispersal limitation. We plan to explore the problem of spatial scale dependence of dispersal limitation for microbial communities. We will obtain microbial species pool of a region by collecting air particles, choose two water samples whose environment conditions and microbial compositions are different, and then develop water microcosm experiments. We use high-throughput sequencing to detect microbial community composition, α and β diversity. We intend to study if microorganisms suffer from dispersal limitation under a natural immigration rate, and explore how dispersal strength influences environmental filtering and drift process at small scales; judge if microbes show “species pool dispersal limitation” at large sales. The study results will contribute to explore the scale dependence problems of dispersal limitation, illuminate microbial community assembly mechanisms, and provide microbial ecology basic theory with experiment tests.