Soil and plant community characteristics under long-term continuous grazing of different intensities in an alpine meadow on the Tibetan plateau

Soil and community characteristics, and their driving factors, were poorly understood in terms of grazing intensity in alpine meadow regions on the Tibetan plateau. We investigated the soil properties and plant communities between areas with long-term light grazing (LG), medium grazing (MG), and high grazing (HG) intensities. It was revealed that grazing activity decreased the soil organic carbon and total nitrogen and phosphorus. MG and HG significantly decreased the aboveground biomass and species biodiversity of alpine meadows compared with LG. A high grazing intensity significantly decreased the species richness compared with LG and MG. MG and HG coverage decreased relative to LG. The available phosphorus and nitrogen were the main direct positive influences stimulating the aboveground biomass of the grassland. However, the available nitrogen played an important direct role in priming the species richness. Grazing intensity decreased both biomass and richness. In conclusion, light grazing provides the most benefits for the biomass and species richness of the alpine meadows of the Tibetan plateau.