Your new experience awaits. Try the new design now and help us make it even better

ORIGINAL RESEARCH article

Front. Microbiol.

Sec. Aquatic Microbiology

Volume 16 - 2025 | doi: 10.3389/fmicb.2025.1667966

Factors influencing the spatial distributions of river microbial communities at the watershed scale: A case study involving the Wuding River Basin

Provisionally accepted
  • Chang’an University, Xi'an, China

The final, formatted version of the article will be published soon.

Microbial communities regulate water quality and biogeochemical cycling in rivers, but their responses to geomorphological factors remain unclear. Water samples were collected in August 2024 (summer wet season) from the Wuding River, and metagenomic sequencing was used to investigate microbial community changes and the influences of geomorphological factors. Environment (nutrients, etc.) exhibited significant spatial heterogeneity with temperature (p < 0.01), total organic carbon (TOC, p < 0.001), dissolved organic carbon (DOC, p < 0.001), chemical oxygen demand (COD, p < 0.05), total phosphorus (TP, p < 0.001) and suspended solids (SS, p < 0.001), which were significantly higher downstream than upstream. Pseudomonadota, Cyanobacteriota, and Actinomycetota were the most important microbial phyla, and Cyanobacteriota (p = 0.016) was significantly more abundant upstream than downstream. The linear discriminant analysis effect size (LEfSe) revealed 8 and 10 biomarkers upstream and downstream, respectively. Upstream microbial communities were adapted to oligotrophic and high-light environments, whereas heterotrophic, carbon-metabolizing communities occurred downstream. Significantly higher ACE (p < 0.05), Chao1 (p < 0.05), Shannon (p < 0.001) and Pielou’s evenness (p < 0.001) indices were observed downstream than upstream. The relative abundance of genes associated with carbon cycling (the methane metabolism pathway, TCA cycle, and rTCA cycle) was greater downstream than upstream, as was the relative abundance of nitrogen functional genes. Elevation affected the upstream microbial communities, whereas temperature, TP, TOC, and nitrate nitrogen affected the downstream communities. The results improve our understanding of how geomorphology drives the environmental factors and then governs the microbial community and their carbon and nitrogen cycling pathways.

Keywords: WuDing River Basin, Gene sequencing, Microbial Diversity, environmental factors, Geomorphological changes

Received: 17 Jul 2025; Accepted: 07 Oct 2025.

Copyright: © 2025 Xue, Xia, Hu, Gong, Wang and Zhao. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence:
Zhoufeng Wang, wangzf@chd.edu.cn
Xiaohong Zhao, xzhao@chd.edu.cn

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.