Soil particle and moisture-related factors determine landward distribution of bacterial communities in a lateral riverside continuum of the Xilin River Basin

Abstract

Continuous landscape components along the lateral riverside are affected by both hydrologic connectivity and disconnectivity. In recent years, anthropogenic activities and climate changes have caused wetland shrinkage and land degradation along the lateral riverside of many arid and semiarid regions. Since microorganisms are major drivers of soil biochemical cycling, it is essential to examine soil microbial communities along the lateral landscape continuum to understand their ecosystem functioning and predict future land changes. Here, we collected samples along a lateral riverbed center-riverbed edge-oxbow lake-floodplain-terrace continuum (i.e., landward distribution) in the Xilin River Basin, Inner Mongolia, China. The floodplain had the highest microbial diversity and heterogeneity, with Bacteroidetes, βand γ-Proteobacteria being the most abundant taxa. In contrast, the terrace had the lowest microbial diversity and heterogeneity, with Acidobacteria, Actinobacteria, Verrucomicrobia, Gemmatimonadetes, and α-Proteobacteria as the most abundant taxa. Silt particle, salinity, and moisture were the most influential factors for landward variation of bacterial communities along the riverside continuum. Altogether, we demonstrate that dominant bacterial lineages, soil particles, and moisture-related factors are valuable indicators of this continuum, which can be leveraged for the early prediction of drought-induced wetland shrinkage and grassland desertification.

Response of soil viral communities to land use changes

“…Generally, artificial irrigation in agricultural field and urban green space can result in higher soil moisture (Fig. 4d ), which is often associated with more connectivity and dispersal as the water can fill the soil pore and promote the diffusion of viral-like particles in soils, and thus facilitating the movement of extracellular viruses and propagation of lytic viruses for new host cells 50 , 51 . In addition, DOC exhibited a significantly positive effect on the putative lysogenic virus abundance (Fig.…”

Dependence of cumulative CO2 emission and microbial diversity on the wetting intensity in drying-rewetting cycles in agriculture soil on the Loess Plateau

“…The soil microbial DNA was extracted for every sample using the E.Z.N.A.® DNA kit for soil (Omega Bio-tek, USA) according to the manufacturer's instructions. The hypervariable regions V3−V4 of the bacterial 16S rRNA gene were amplified with the pairs 338F/806R (Tong et al, 2020;Yu et al, 2021). The ITS1−ITS2 of the fungal ITS rRNA gene were amplified with the primers ITS1F/ITS2R (Adams et al, 2013).…”