The researchers investigated the land surface vegetation coverage, soil particle size and organic carbon content in the typical steppe under overgrazing, cultivation and exclosure  in Inner Mongolia and analyzed the influences of human activity on grassland soil erosion,　they concluded the following conclusion: Compared to enclosed grassland, the vegetation coverage, height and root biomass of overgrazing grassland decreased by 44.23%, 80.71% and 37.83% respectively. Due to the decline of vegetation coverage and root density, the soil of overgrazing grassland demonstrated a significant wind erosion. Overgrazing resulted in the increase of sand content in the surface soil and about 100% increase of the mean soil particle size. Furthermore, cultivation had led to serious soil wind erosion and 2.5 times increase in mean particle size. The overgrazed and cultivated grassland had become an important source of sand dust. The coarsening of soil particle directly aroused the decline of soil organic carbon content, and when 1 percent of soil particle content below 0.1 mm was blown away by wind, organic carbon content in soil reduced 0.2546 g·kg-1.

issued by <<Journal of Desert Research>>