Abstract：
A combined temporal and spatial research approach helps us to evaluate the ecological status of a river scientifically and comprehensively. To understand the response mechanisms of bacteria in the Li River to different environments, we conducted a 1-year study (2020-2021) and collected water samples from 18 sections of the river in October, January, April, and August. 16S sequencing was used to study the composition and structure of bacterial communities in Li River at different temporal and spatial scales. The results showed that NO3--N, TP, T, pH, and DO were significantly different on spatial and temporal scales. Alpha diversity of planktonic bacteria in Li River fluctuated significantly with the season, reaching its highest in summer. Proteobacteria remained the most dominant phylum in all seasons, but the differential microorganisms varied between seasons. Although the abundance of metabolic functions of planktonic bacteria did not show significant differences between seasons, we found that DO, TP, T, and COD were the key environmental factors affecting bacterial metabolism. In addition, the co-occurrence network analysis showed that the autumn network had a higher number of nodes and edges and exhibited a high degree of complexity, while the summer network had the highest degree of modularity and exhibited greater stability. These results deepen our knowledge of the response mechanisms of river microorganisms to temporal and spatial changes and provide a scientific reference for the study of river ecosystems.
摘要：
时空结合的研究方法有助于我们科学，全面地评估河流的生态状况。为了解漓江中细菌对不同环境的响应机制,我们进行了一项为期1年的研究(2020-2021年)，并在10月收集了18个河段的水样，一月,April,和八月。采用16S测序技术在不同时空尺度上研究了漓江细菌群落的组成和结构。结果表明,NO3--N,TP,T,pH值,和DO在时空尺度上有显著差异。漓江浮游细菌的α多样性随季节波动显著,在夏天达到最高。在所有季节中，变形杆菌仍然是最主要的门，但是不同的微生物季节不同。尽管浮游细菌代谢功能的丰度在季节之间没有显着差异，我们发现DO,TP,T,COD和COD是影响细菌代谢的关键环境因子。此外,共生网络分析表明，秋季网络具有更多的节点和边，表现出高度的复杂性，而夏季网络的模块化程度最高，表现出更大的稳定性。这些结果加深了我们对河流微生物对时空变化的响应机制的认识，为河流生态系统的研究提供了科学参考。
