Zhu Aiping, Liang Zuobing, Gao Lei, Xie Zhenglan
School of Geography and Tourism, Anhui Normal University, Wuhu, China.
Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Chinese Academy of Sciences, Guangzhou, China.
Front Microbiol. 2024 Aug 26;15:1430073. doi: 10.3389/fmicb.2024.1430073. eCollection 2024.
Bacteria play a crucial role in pollutant degradation, biogeochemical cycling, and energy flow within river ecosystems. However, the underlying mechanisms governing bacterial community assembly and their response to environmental factors at seasonal scales in subtropical rivers remain poorly understood. In this study, we conducted 16S rRNA gene amplicon sequencing on water samples from the Liuxi River to investigate the composition, assembly processes, and co-occurrence relationships of bacterial communities during the wet season and dry season. The results demonstrated that seasonal differences in hydrochemistry significantly influenced the composition of bacterial communities. A more heterogeneous community structure and increased alpha diversity were observed during the dry season. Water temperature emerged as the primary driver for seasonal changes in bacterial communities. Dispersal limitation predominantly governed community assembly, however, during the dry season, its contribution increased due to decreased immigration rates. Co-occurrence network analysis reveals that mutualism played a prevailing role in shaping bacterial community structure. Compared to the wet season, the network of bacterial communities exhibited higher modularity, competition, and keystone species during the dry season, resulting in a more stable community structure. Although keystone species displayed distinct seasonal variations, and were consistently abundant keystone species maintaining network structure in both seasons. Our findings provide insights into how bacterial communities respond to seasonal environmental changes, uncovering underlying mechanisms governing community assembly in subtropical rivers, which are crucial for the effective management and conservation of riverine ecosystems.
细菌在河流生态系统中的污染物降解、生物地球化学循环和能量流动中发挥着关键作用。然而，在亚热带河流中，细菌群落组装的潜在机制及其在季节尺度上对环境因素的响应仍知之甚少。在本研究中，我们对来自流溪河的水样进行了16S rRNA基因扩增子测序，以研究雨季和旱季细菌群落的组成、组装过程和共现关系。结果表明，水化学的季节差异显著影响了细菌群落的组成。在旱季观察到更不均匀的群落结构和增加的α多样性。水温是细菌群落季节变化的主要驱动因素。扩散限制主要控制着群落组装，然而，在旱季，由于移民率下降，其贡献增加。共现网络分析表明，互利共生在塑造细菌群落结构中起主导作用。与雨季相比，旱季细菌群落网络表现出更高的模块性、竞争性和关键物种，从而导致更稳定的群落结构。尽管关键物种表现出明显的季节变化，并且在两个季节中都是维持网络结构的持续丰富的关键物种。我们的研究结果为细菌群落如何响应季节性环境变化提供了见解，揭示了亚热带河流中群落组装的潜在机制，这对于河流生态系统的有效管理和保护至关重要。
