A comparative study of soil nutrient availability and enzyme activity under biological soil crusts in different erosion regions of the Loess Plateau, China

Purpose The influences of biological soil crusts (BSCs) on soil properties have been investigated extensively. However, few studies have compared soil properties under different types of BSCs in different erosion regions. Methods Three erosion regions (water erosion, wind-water crisscross erosion, and wind erosion regions) were identified in the Loess Plateau, and we collected subsoil samples of cyanobacteria and moss crusts in each region (crust coverage > 95%), respectively. The variations of soil nutrient content and enzyme activity were evaluated, and the most influential soil properties were determined. Results Most of the tested soil properties were significantly affected by erosion and crust types ( p < 0.05). Soil pH was significantly higher, while soil electrical conductivity (EC) was substantially lower in the water erosion region than the water-wind crisscross erosion and wind erosion regions ( p < 0.05). Soil nutrient content and enzyme activity were higher in the water erosion region compared to the wind erosion and wind-water erosion regions ( p < 0.05). In the subsoil below BSCs, most of the soil nutrient availability and enzyme activity was higher under moss crusts than cyanobacteria crusts ( p < 0.05). Conclusion Our results suggested that there were differences in the effects of two types of BSCs on the soil nutrient availability and enzyme activity across the three typical erosion regions in the Loess Plateau, and the magnitude of these effects followed the order of: water erosion regions > wind erosion regions > wind-water erosion crisscross regions, and moss crusts > cyanobacteria crusts.