The heterogeneous nature of lotic habitats plays an important role in the complex ecological and evolutionary processes that structure the microbial communities within them. Due to such complexity, our understanding of lotic microbial ecology still lacks conceptual frameworks for the ecological processes that shape these communities. We explored how bacterial community composition and underlying ecological assembly processes differ between lotic habitats by examining community composition and inferring community assembly processes across four major habitat types (free‐living, particle‐associated, biofilm on benthic stones and rocks, and sediment). This was conducted at 12 river sites from headwater streams to the main river in the River Thames, UK. Our results indicate that there are distinct differences in the bacterial communities between four major habitat types, with contrasting ecological processes shaping their community assembly processes. While the mobile free‐living and particle‐associated communities were consistently less diverse than the fixed sediment and biofilm communities, the latter two communities displayed higher homogeneity across the sampling sites. This indicates that the relative influence of deterministic environmental filtering is elevated in sediment and biofilm communities compared with free‐living and particle‐associated communities, where stochastic processes play a larger role.

中文翻译：

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对比群落组装过程沿河流连续体构造流水细菌元群落


栖息地的异质性在构建其内部微生物群落的复杂生态和进化过程中发挥着重要作用。由于这种复杂性，我们对微生物生态学的理解仍然缺乏塑造这些群落的生态过程的概念框架。我们通过检查群落组成并推断四种主要栖息地类型（自由生活、颗粒相关、底栖石头和岩石上的生物膜以及沉积物）的群落组装过程，探索了不同生境之间细菌群落组成和潜在生态组装过程的差异。这项研究是在英国泰晤士河从源头到主要河流的 12 个河流地点进行的。我们的结果表明，四种主要栖息地类型之间的细菌群落存在明显差异，不同的生态过程塑造了它们的群落组装过程。虽然移动自由生活和颗粒相关群落的多样性始终低于固定沉积物和生物膜群落，但后两个群落在整个采样点表现出更高的同质性。这表明，与随机过程发挥更大作用的自由生活和颗粒相关群落相比，沉积物和生物膜群落中确定性环境过滤的相对影响更大。