Differences in soil bacterial communities of desert grasslands in Tianshan under different grazing disturbances

The objective of the study was to elucidate the effect of the composition and structure of the soil bacterial community in the desert grassland on Seriphidium transiliense in the middle part of the northern slope of the Tianshan Mountains under different grazing intensities. In this study, we investigated the composition of the soil bacterial community and soil physical and chemical properties of desert grassland ecosystems under light grazing (LG) and heavy grazing (HG) treatments using plant community surveys and soil microbial high-throughput sequencing technology. We explored the effects of grazing on soil bacterial communities and soil physical and chemical factors in grassland ecosystems. The results indicated: 1) From the perspective of the soil bacterial diversity index, HG decreased the Chao1 species richness index and ACE species richness index (P < 0.05), but had no substantial effect on the Shannon diversity index and Simpson diversity index ( P > 0.05). 2) From the soil bacterial community structure perspective, LG increased the relative abundance of Actinobacteria and Chloroflex, and HG increased the relative abundance of Proteobacteria, Acidobacteria, and Firmicutes ( P < 0.05). 3) Soil physical and chemical properties did not change substantially at HG and LG levels. 4) From the analysis of the relationship between the soil bacterial community and soil physical and chemical properties, it was evident that soil total nitrogen was the decisive factor leading to changes in the soil bacterial community. Our results reveal the changes in the soil bacterial community in the desert grassland of Seriphidium transiliense under grazing conditions, provide a theoretical basis for the mechanism of interaction between the soil and the soil bacterial community structure and diversity in the desert grassland, and provide a reference for the utilization, protection, and restoration of desert grassland ecosystems.