Lu Lunhui, Tang Qiong, Li Hang, Li Zhe
Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China.
Key Laboratory of Hydraulic and Waterway Engineering of the Ministry of Education, Chongqing Jiaotong University, Chongqing, 400074, China.
Environ Microbiol. 2022 Apr;24(4):1760-1774. doi: 10.1111/1462-2920.15872. Epub 2022 Jan 12.
Planktonic bacterial and microeukaryotic communities play important roles in biogeochemical cycles, but their biogeographic patterns and community assembly processes in large damming rivers still remain unclear. In this study, 16S rRNA and 18S rRNA coding genes were used for sample sequencing analysis of planktonic bacterial and microeukaryotic communities in the upper Yangtze River. The upper Yangtze River was divided into dam-affected zones and river zones based on the influence of dams. The results showed that there were significant differences in the bacterial and microeukaryotic communities between the two zones and that dams significantly reduced the α-diversity of the bacterial communities. Co-occurrence network analysis indicated that networks in the river zone were denser than those in the dam-affected zone. The relationships among species in bacterial networks were more complex than those in microeukaryotic networks. Dispersal limitation and ecological drift were the main processes influencing planktonic bacterial and microeukaryotic communities in the dam-affected zone respectively, whereas the role of deterministic processes increased in the river zone. Anthropogenic activities and hydraulic conditions affected suspended sediment and controlled microbial diversity in the river zone. These results suggest that dams impact planktonic bacteria more strongly than planktonic microeukaryotes, indicating that the distribution patterns and processes of the bacterial and microeukaryotic communities in large rivers are significantly different.
浮游细菌和微型真核生物群落对生物地球化学循环具有重要作用，但其在大型筑坝河流中的生物地理模式和群落组装过程仍不清楚。在本研究中，利用16S rRNA和18S rRNA编码基因对长江上游浮游细菌和微型真核生物群落进行样本测序分析。基于大坝的影响，将长江上游划分为受大坝影响区和河流区。结果表明，两区的细菌和微型真核生物群落存在显著差异，大坝显著降低了细菌群落的α多样性。共现网络分析表明，河流区的网络比受大坝影响区的网络更密集。细菌网络中物种间的关系比微型真核生物网络中的更复杂。扩散限制和生态漂变分别是影响受大坝影响区浮游细菌和微型真核生物群落的主要过程，而在河流区确定性过程的作用增强。人为活动和水力条件影响河流区的悬浮泥沙并控制微生物多样性。这些结果表明，大坝对浮游细菌的影响比对浮游微型真核生物的影响更强，这表明大型河流中细菌和微型真核生物群落的分布模式和过程存在显著差异。
