关键词: 土壤微生物, 磷脂脂肪酸, 毛乌素沙地, 植被恢复

Abstract: Soil microorganisms play a crucial role as a link between vegetation and soil nutrient cycling. However, it is unclear how vegetation and soil influence microbial community during the ecological restoration process of the Mu Us Desert. Using phospholipid fatty acid (PLFA) markers and integrating shrub, herbaceous plants, and soil factors, we explored the characteristics and regulations of soil microbial community changes. In this study, we used and took the soil after 10, 30, 50, and 70 years of Caragana korshinskii sand-fixing forest restoration, with moving dunes as a control (0 year). The results showed that the ecological restoration effect index increased significantly with the increase of recovery years. The total PLFA contents in 0, 10, 30, 50, and 70 years were 47.75, 55.89, 63.53, 67.23, and 82.29 nmol·g^-1, respectively. With the increases of ecological restoration index, the biomass of fungi and bacteria, as well as the ratio of Gram-positive to Gram-negative bacteria, all showed significant increase, while the biomass of Gram-positive and Gram-negative bacterial communities, and the ratio of fungi to bacteria, demonstrated significant decrease. Shrub, herbaceous plants, and soil factors could explain 72.4% of the vari-ation of soil microbial community composition, with higher contribution of soil factors than vegetation factors. The total content of phospholipid fatty acids of soil microbial community in Mu Us Desert increased with the increases of restoration years. Soil water content, pH, total nitrogen, and soil organic carbon were the main driving factors affecting the characteristics of soil microbial community. With the increases of restoration years of C. korshinskii sand-fixation forests in the Mu Us Desert, there were significant changes in the structure of soil microbial communities, which were primarily driven by soil factors.

Key words: soil microorganism, phospholipid fatty acid, Mu Us Desert, vegetation restoration