Land-use changes influence soil bacterial communities in a meadow grassland in Northeast China

The conversion of natural grassland into agricultural fields is an intensive anthropogenic perturbation commonly occurring in semi-arid regions, and this perturbation strongly affects soil microbiota. In this study, the influences of land-use conversion on the soil properties and bacterial communities in Horqin Grasslands in Northeast China were assessed. This study aimed to investigate (1) how the abundances of soil bacteria changed across land-use types; (2) how the structure of soil bacterial community was altered in each land-use type; and (3) how these variations were correlated with soil physical and chemical properties. The variations in diversities and compositions of bacterial communities and relative abundance of dominant taxa were detected in four distinct land-use systems, namely, natural meadow grassland, paddy field, upland field, and poplar plantation, through high-throughput Illumina MiSeq sequencing technique. Results indicated that land-use changes primarily affected soil physical and chemical properties and bacterial community structure. Soil properties, namely, organic matter, pH, total N, total P, available N and P, and microbial biomass C, N, and P, influenced the bacterial community structure. The dominant phyla and genera were almost the same among the land-use types, but their relative abundances were significantly different. The effects of land-use changes on the structure of soil bacterial communities were more quantitative than qualitative.