Effects Of Wind Erosion And Grazing On Plant Community Structure In A Temperate Steppe

Grasslands account for 40.5%of Earth's land area,store approximately 30%of organic carbon of terrestrial ecosystems,and provide 30-50%of the livestock products around the world.As the main land use of grasslands,grazing can substantially influence grassland community structure and increase the areas of bare soil surface,subsequently leading to the enhancements in the frequency of wind erosion.As one of the causes of dust storms,wind erosion can lead to coarsening of soil surface and reduction of soil nutrients by blowing away fine particulates of topsoil,with consequent effects on plant community structure and ecosystem carbon cycle.During the past decades,numerous studies have focused on the causes of wind erosion.However,little attention has been taken to estimate influences of wind erosion and its two processes,i.e.wind erosion and dust deposition,on plant community structure.In addition,how grazing may affect the responses of plant community structure to wind erosion and its two processes remains elusive.Therefore,a field manipulative experiment was established to examine the effects of wind erosion and grazing on plant community structure by simulating wind erosion and grazing simultaneously in a temperate steppe of northern China.Plant species richness was decreased by 7.3%by dust deposition,but increased by 9.1%by grazing.Wind erosion and grazing reduced community cover by 17.0%and 4.3%,respectively.By contrast,dust deposition enhanced community cover by 5.7%.There was no interaction between wind erosion and grazing on plant species richness or community cover.The findings of this study can improve the understanding of the effects of wind erosion and grazing on plant community structure,and facilitate model parameterization and calibration in predicting wind erosion influences on terrestrial ecosystems under land use practice.