Soil particles and elevation shape the distribution of prokaryotic communities in Poyang Lake

The differential deposition and elevation changes of soil are crucial factors influencing the transformation of wetland ecological functions. This study aims to investigate the effects of soil particle composition and elevation on prokaryotic communities and associated nutrient cycles. In this study, two distinct soil collection areas with varying sedimentary environments in Poyang Lake, China, were selected, and wetland soil samples were collected along the wetland slope, ranging from low to high altitude. Employing 16S rRNA gene sequencing and analyses of soil enzyme activities, we investigated prokaryotic (archaeal and bacterial) communities and their functions related to carbon, nitrogen, and phosphorus metabolism. The results showed that the Shannon indices of Archaea and Bacteria, as well as network complexity, were significantly greater in high-sand soils (sand, 55 %–93 %) compared to high-clay soils (sand, 23 %–42 %). The diversity (ACE and PD_whole_tree) of Archaea and Bacteria declined with elevation. Carbon and phosphorus-related enzyme activity was higher in clay-rich soils than in sand-rich soils, while nitrogen-related enzyme activity was not affected by soil particles. All carbon metabolism-related enzyme activities were influenced by elevation, unlike nitrogen and phosphorus. Furthermore, we found that soil particles indirectly affect prokaryotic communities by correlating with soil nutrients and pH, while elevation indirectly affects prokaryotic communities by correlating with soil moisture and pH. Soil particles contributed more significantly than elevation to the variation observed in archaeal and bacterial communities. These findings enhance our understanding of the effects of soil particles and elevation on wetland ecosystems from a microbial perspective.