Microbial Characteristics and Dominant Factors of Biocrusts on Steep Erosional Slopes in the Red Soil Hilly Region

Biocrusts play vital ecological roles on steep slopes in the red soil region, dominated by Ferralsols, yet their basic characteristics remain poorly understood. Here, we examined soil fertility, enzyme activities, and microbial characteristics of cyanobacterial and moss biocrusts on collapsing walls, using bare soil as a control. Our results demonstrated that moss biocrusts significantly outperformed both cyanobacterial biocrusts and bare soil. Phototrophic biomass (indicated by chlorophyll a content) was 7 times higher in moss biocrusts compared with bare soil, and the photosynthetic capacity was highest in moss biocrusts. Soil fertility and enzyme activities were also significantly higher in biocrusts, especially moss biocrusts, than in bare soil. Specifically, soil organic matter and total nitrogen were 3.4 and 6 times higher in moss biocrusts than in bare soil, respectively. Bacterial richness and diversity were significantly elevated in biocrusts, and the greatest increases were observed in moss biocrusts, with Chao 1 index being 2.8‐fold higher in moss biocrusts than in bare soil. Dominant microbial taxa varied significantly among treatments, and total phosphorus was identified as the key nutrient factor. These results enhance our understanding of the basic properties of biocrusts and the key factors affecting their properties on steep slopes in the red soil hilly region.