Salinity controls soil microbial community structure and function in coastal estuarine wetlands

Abstract

Summary Soil salinity acts as a critical environmental filter on microbial communities, but the consequences for microbial diversity and biogeochemical processes are poorly understood. Here, we characterized soil bacterial communities and microbial functional genes in a coastal estuarine wetland ecosystem across a gradient (~5 km) ranging from oligohaline to hypersaline habitats by applying the PCR‐amplified 16S rRNA (rRNA) genes sequencing and microarray‐based GeoChip 5.0 respectively. Results showed that saline soils in marine intertidal and supratidal zone exhibited higher bacterial richness and Faith's phylogenetic diversity than that in the freshwater‐affected habitats. The relative abundance of taxa assigned to Gammaproteobacteria, Bacteroidetes and Firmicutes was higher with increasing salinity, while those affiliated with Acidobacteria, Chloroflexi and Cyanobacteria were more prevalent in wetland soils with low salinity. The phylogenetic inferences demonstrated the deterministic role of salinity filtering on the bacterial community assembly processes. The abundance of most functional genes involved in carbon degradation and nitrogen cycling correlated negatively with salinity, except for the hzo gene, suggesting a critical role of the anammox process in tidal affected zones. Overall, the salinity filtering effect shapes the soil bacterial community composition, and soil salinity act as a critical inhibitor in the soil biogeochemical processes in estuary ecosystems.

Microbial residues as the nexus transforming inorganic carbon to organic carbon in coastal saline soils

“…In our study, we found a great changes in soil salinity, indicating that salinity might be a main factor influencing ecosystem structure and function in the coastal saline lands, such as soil C cycling, plant growth, or microbial metobolism (Wong et al, 2010;Cho et al, 2018;Zhang et al, 2021a). Along the natural salinity gradient, SIC was higher at low salinity ( < 6 ‰) and declined as salinity increased, suggesting that salinity stress influences SIC dynamic through the variation in soil alkalinity or biologically respired CO 2 (Xie et al, 2009;Chi et al, 2018;Wang et al, 2019).…”

“…Plants (e.g, maize and Phragmites) growing in low salinity soils exhibited high photosynthetic C fixation could increase plant C into soil through litter and root exudates, thus enhancing SOC accumulation; whereas plants (e.g, Tamarix chinensis and Suaeda salsa, with low photosynthetic C fixation) growing in high salinity soils resulted in the decline in SOC storage due to decreased litter and root exudates (Hessini et al, 2019;Xia et al, 2019). Additionally, soil microbial structure and functions (e.g., biomass and activity) are substantially affected by salinity (Rath et al, 2019;Zhang et al, 2021a). The previous researches have reported that low salinity soils could synthesize more microbial biomass than high salinity soils (Chen et al, 2021), which Fig.…”

Comparing the concentrations of heavy metals on two bivalve species in Santos Bay, Brazil: Subsidies to understanding the assimilation dynamic of bivalve contaminants

“…Most of the time, estuaries are marked by horizontal salinity gradients (Telesh & Khlebovich, 2010; Zhang et al, 2020). Salinity usually decreases from the ocean toward the head of the estuary due to freshwater discharge.…”

Alteration of Nutrient Substrates and Absence of Seawater Due to Coastal Embankments Affects Soil Microbial Communities in Salt Marshes of Eastern China

“…Soil microbial communities are considerably in uenced by biotic (e.g., the quantity and quality of plant materials) (Angel et al 2010) and abiotic (e.g., climate, soil type, and soil physicochemical properties) factors (Bainard et al 2016;Nguyen et al 2018). Plant properties, such as the aboveground and belowground biomass, strongly affect soil bacteria and archaea (Brotosudarmo et Similarly, soil salinity restricts the growth of bacteria and archaea by limiting water availability (Rath and Rousk 2015;Zhang et al 2021). Additionally, soil moisture is a vital driver of soil bacterial community composition, especially the proportion of aerobic and anaerobic bacteria, because it affects soil aeration conditions (Guo and Zhou 2020; Yang et al 2020;Sun et al 2021).…”