The bacterial communities and its relationship with physicochemical properties in an urban riparian zone adjacent to different revetments

The riparian zone is the critical ecotone between terrestrial and aquatic ecosystems. The Fen River plays an important role in environmental protection of the city of Taiyuan, Shanxi Province, China. Over the last few decades, various revetments have been built to protect and restore the riparian zone of the Fen River. However, it is poorly understood which type of revetment is more conducive to material recycling and energy flow between water and soil. The microbial community in the riparian zone plays a crucial role in maintaining biodiversity. This study investigated the composition and diversity of bacterial communities in soils and sediments using 16S rRNA amplicon sequencing based on Illumina NovaSeq, and identified the key environmental drivers of bacterial community composition and diversity using correlation and ordination analysis. Compared to the ecological sandbag revetment (SR), the gabion revetment (GR) had higher soil organic matter (SOM) and nitrate nitrogen (NO 3 -N) concentrations. And the GR soil had higher Simpson and Shannon diversity index values than the SR and the concrete revetment (CR) soils. The distance had a significant effect on bacterial diversity, and the Chao, Shannon, ACE, and PD indices were significantly lower at 1.0 m than at other distances, and there were no significant differences in physicochemical properties. The TP had a significant effect on the bacterial community composition, which explained 47.89 % of the variances. Our results suggested that the GR was more conducive to the biodiversity protection, and the water-land interaction mainly occurs in the range of 1.0 m away from the shore in study area. These results can provide theoretical support for biodiversity conservation, management and restoration of urban riparian zones.