Heavy Metal Characteristics and Their Association With Microbial Communities of Wetland Soils of Shengjin and Caizi Lakes, China

Wetland soils are among the ecosystems most vulnerable to anthropogenic disturbances, and they play critical roles in biogeochemical cycling and energy exchange. In this study, we investigated the characteristics of heavy metal distribution and microbial community structures in soil samples from Shengjin Lake and Caizi Lake in China. Analysis of soil physicochemical properties revealed a significant difference in soil pH between the two lakes, whereas no significant differences were detected in organic matter content or cation exchange capacity. Soils from Caizi Lake exhibited significantly higher concentrations of Pb, As, and Hg than those from Shengjin Lake, whereas Cd and Cr concentrations did not differ significantly between the two lakes. Soil microbial analysis demonstrated that Proteobacteria, Actinobacteriota, and Chloroflexi were the dominant phyla across all samples. Alpha diversity and principal coordinate analysis revealed significant differences in soil microbial communities between Shengjin and Caizi Lakes. LEfSe analysis indicated that Pedobacter, Nocardioides, and Flavobacterium were significantly enriched in the soils from Shengjin Lake, whereas Arthrobacter was significantly more abundant in the soils from Caizi Lake. To further explore the relationships between heavy metals and microbial communities, we analyzed the correlation heatmaps of the associations among heavy metals, microbial taxa, and KEGG functional pathways in samples from both lakes. Collectively, this study enhances the current understanding of heavy metal distribution and microbial community characteristics in wetland soils and provides a scientific basis for early environmental pollution warnings in the wetland ecosystems of Shengjin and Caizi Lakes.