Effects of Grazing Exclusion on Vegetation and Soil Properties of a Leymus chinensis Steppe in China

Livestock grazing exclusion is the most widely used grassland restoration strategy. However, the impacts of long-term grazing exclusion remain unknown. To clarify the impacts of long-term grazing exclusion on plant and soil features, we examined the plant biomass, plant diversity, and the physical, chemical, and enzymatic soil properties of an area with a history of 40 years of grazing exclusion within the Xinlin Gol grassland of China. Our results showed that grazing exclusion increased the plant diversity and biomass effectively, especially the gramineous, forb, and shrub biomass and the forb and shrub diversity. In addition, grazing exclusion reduced the bulk density of the soil, increased its water content, amount of organic matter, and available nitrogen content, and slowed down the decreasing trend in the amount of total nitrogen with the increase in soil depth. Plant biomass and litter mass was identified as important to connecting plant features and soil nutrient content. In particular, shrub biomass and diversity characteristics were positively correlated with each other, and had the closest coupling with soil properties among all plant functional groups. After considering the results, we concluded that grazing exclusion can be effective in restoring a natural grassland environment.