关键词: 土壤微生物群落, 人工梭梭林, 退化, 土壤理化性质

Abstract: Aims As a typical ecologically fragile zone in northern China, the Hexi Corridor is plagued by vegetation degradation and serious soil nutrient loss. As a key sand-fixing species in the Hexi Corridor, the degradation of Haloxylon ammodendron poses a serious threat to the ecological security of the region. The research about differences in soil microbial community characteristics and the influencing factors of artificial forests under different degradation levels was carried out, which can help to formulate reasonable restoration strategies. Methods In this study, the changes of soil physicochemical properties and microbial community diversity of artificial Haloxylon ammodendron forests under different degradation levels were analyzed in order to clarify the trend of microbial diversity and the key factors controlling the distribution of microbial communities in the degradation process of the forest land. Important findings The results showed that: (1) The content of Actinobacteriota, Chloroflexi and Acidobacteriota in bacteria increased significantly with the deterioration of forest land, while the content of Basidiomycota in fungi increased and then decreased, and the content of Chytridiomycota decreased and then increased; (2) The diversity of soil bacteria at moderate and heavy degradation was significantly higher than that of undegraded forest land, and the diversity of fungi was significantly higher than the rest of the degradation levels at slight degradation; (3) Soil organic carbon, total nitrogen, and total phosphorus were the main factors affecting the composition of soil bacterial communities in artificial Haloxylon ammodendron forests, while pH of soil, total nitrogen and water content were the main factors affecting the composition of fungal communities in forests. The study shows that there are differences in soil environmental factors affecting the composition and structure of soil microbial communities in artificial Haloxylon-ammodendron forests at different degradation levels. Therefore, when developing restoration strategies for degraded forests, differentiated ecological restoration strategies should be adopted based on the analysis of region-specific environmental drivers.

Key words: soil microbial communities, artificial Haloxylon ammodendron forests, degradation, soil physicochemical properties