Soil salinity and nutrients availability drive patterns in bacterial community and diversity along succession gradient in the Yellow River Delta

Abstract

Exploring the main driving factors of microbial community in different succession stages of coastal wetland could provide insights into ecological restoration activities. The present study examined the soil microbial assemblage in a succession gradient of the coastal wetland in the Yellow River Delta (YRD) and elucidated the contributions of spatial structure, vegetation, and soil properties to microbial communities. Plant and soil samples in four succession stages from (S1, S2, S3, and S4) were selected in the coastal wetland of YRD. Soil bacterial community was analyzed using the 16S rRNA high-throughput sequencing technique. Partial mantel test and redundancy analysis were conducted to elucidate the relationship between bacterial community structure and environmental parameters. Soil pH and salinity decreased and soil nutrients increased with succession from mud flat to the late stage. Higher bacterial richness and diversity were also observed with coastal wetland succession. Although most of the soil properties, vegetation, and spatial distribution have an impact on the bacterial community, soil salinity and nutrient availability (e.g., total nitrogen content, nitrate content and dissolved organic carbon) have the greatest influence on the shift in the bacterial community along the succession gradient. Taken together, soil salinity and nutrients availability could be major drivers of variations in bacterial assemblage with coastal wetland succession. These findings improve our understanding of soil microbes as affected by environmental factors and microbial diversity could be considered as a helpful tool to evaluate the efficiency of ecological restoration in coastal wetlands.