Effects of revetments on soil bacterial communities in the adjacent tidal urban river-riparian interface

Abstract

River-riparian interfaces (RRIs) of urban rivers are where river ecosystems interact with the riparian soil ecosystems. However, with the intensification of urbanization, the construction of various revetments changes the energy exchange process between the river and the RRI, affects the soil properties, and then affects the soil bacterial community composition and structure. In this study, natural (NR), permeable (PR), and impervious revetments (IR) of the same river section were selected. The composition and abundance of soil bacterial communities were detected by PCR amplification technology. The Alpha diversity, Beta diversity, community composition, and environmental factor correlations of bacterial communities were analyzed. The results showed: (1) The dominant bacterial genera of NR, IR, and PR were similar, mainly Anaerolineae, Vicinamibacterales, Ardenticatenales, and Rokubacteriales. There were 504 bacterial genera with the same NR, IR, and PR, accounting for NR, IR, and PR bacterial genera 69.52%, 69.33%, and 62.22% of the total, respectively. (2) Due to the material and energy exchange between soil water and river water and the buffering effect of permeable revetment on frequent river water level changes, the bacterial community richness, community diversity, and lineage diversity of PR are higher than those of NR and IR. (3) SOM, pH, oxygen, and soil nutrients are critical environmental factors that affect the composition and abundance of soil bacterial communities at RRI. The research results provide a theoretical basis for further exploring the impact of urban river revetment on the service function of soil ecosystems at RRI.