Effects of Different Biocrust Types on Soil Organic Carbon and Its Transformation in the Water-wind Erosion Crisscross Region of the Loess Plateau

[Objective] Wind-water erosion crisscross region in Loess Plateau is a typical fragile ecosystem. Biological soil crusts (BSCs) are widely distributed in this region and play key roles in the accumulation and transformation of soil organic carbon (SOC). However, the effect of BSCs succession and microorganisms on enzymes related to organic carbon conversion is still unclear. [Methods] In this manuscript, SOC contents, microbial number and enzymes related with carbon conversion in different BSCs types were investigated. The relationships among SOC, microbial number and enzume activities related with carbon conversion were also analyzed by SEM model. [Results] (1) BSCs succession significantly inceased SOC content and enzyme activities related with carbon conversion. SOC and enzyme activities in BSCs layer(0—2 cm) were significantly higher than those in bare sand 2—5 cm soil layer (p