Assessing the impact of grazing management on wind erosion risk in grasslands: A case study on how grazing affects aboveground biomass and soil particle composition in Inner Mongolia

Soil wind erosion has consistently been a serious ecological problem in northern China. In recent decades, the grasslands of Inner Mongolia have suffered severe degradation due to overgrazing. After vegetation degradation, the surface roughness and ability to intercept wind and sand decrease, resulting in severe soil wind erosion. Soil particles of different sizes have different sensitivities to wind erosion; those with smaller particle sizes are usually more susceptible to wind erosion. Therefore, the composition of surface soil particles can be an indicator of the local soil wind erosion status and risk. In this study, we used the typical grasslands of Inner Mongolia as the object and set different grazing intensities (i.e., low grazing, moderate grazing, high grazing and no grazing). We assessed the risk of grazing-induced grassland degradation and soil erosion by analyzing changes in vegetation and surface soil particle composition. We found that wind erosion mainly occurred in soils with particle sizes of 0.075–0.5 mm. Low grazing had little influence on aboveground biomass but increased topsoil compaction when compared with no grazing. High grazing reduced aboveground biomass, while trampling caused surface fragmentation and increased the risk of soil erosion, resulting in a coarser soil texture. We suggest that in practical management, the occurrence of soil wind erosion can be reduced by appropriately reducing grazing pressure, and the cessation of grazing is not the best method for grassland utilization and restoration