Moderate grazing intensity and pika disturbance can enhance plant diversity and soil nutrient cycling in the alpine grasslands of the Qinghai-Xizang Plateau

Grazing livestock and pikas, as the primary herbivores in grasslands, influence the health of grassland ecosystems through activities such as feeding, burrowing, and trampling. This study reviews 86 articles and examines the effects of varying grazing levels and pika activity on alpine grassland vegetation and soil in the Qinghai-Xizang Plateau, providing scientific insights to guide grassland conservation efforts. The research shows that: 1) Both grazing and pika disturbance significantly reduce aboveground biomass (AGB) in alpine grasslands (p < 0.05). Moderate grazing increases diversity indices, while pika disturbance has the opposite effect. 2) As grazing intensity increases, there is a significant decrease in total nitrogen (TN), total phosphorus (TP), and soil organic matter (SOM) content (p < 0.05). However, moderate pika disturbance leads to a significant increase in TP and TN content (p < 0.05). 3) In grazing trials, bulk density (BD) and the Shannon-Wiener index are significant positive drivers. Conversely, during pika disturbance, the Shannon-Wiener index and total nitrogen (TN) act as significant positive drivers, while BD is a significant negative driver. The study's findings indicate that moderate grazing intensity and pika disturbance can enhance plant diversity indices in grasslands, as well as improve soil structure and nutrient levels. Therefore, establishing a reasonable grazing system and controlling the pika population are effective methods for managing alpine grasslands.