Rooting by Tibetan pigs diminishes carbon stocks in alpine meadows by decreasing soil moisture

Aims Carbon stocks in alpine meadows on the Qinghai-Tibetan Plateau are being threatened by increases in livestock herding practices. However, the extent to which current fast-growing disturbance by Tibetan pig rooting alters carbon stocks in these meadows and the underlying processes are still unclear. Methods We conducted a 3-year study in meadows with three different plant communities on the southeast Qinghai-Tibetan Plateau to explore the effects of rooting by Tibetan pigs on carbon stocks. Results Rooting by Tibetan pigs decreased plant biomass carbon (PBC), soil organic carbon (SOC), microbial biomass carbon (MBC), and ecosystem carbon (EC) by 91.25%, 30.57%, 28.94%, and 40.47%, respectively. Soil moisture (SM) was the most significant factor negatively associated with PBC, SOC, and EC. Additionally, a decreased SM by rooting also exerted an indirect effect on MBC by directly reducing plant biomass. Conclusions Rooting by Tibetan pigs diminishes carbon stocks by decreasing SM, threatening carbon stocks stored in alpine meadows. Thus, caging or reducing the breeding number of Tibetan pigs combined with restoring soil water levels would be effective ways to recover and maintain carbon stocks in alpine meadows on the Qinghai-Tibetan Plateau.

Automated summary

The study found that rooting by Tibetan pigs significantly reduced plant biomass carbon, soil organic carbon, microbial biomass carbon, and ecosystem carbon in alpine meadows on the Qinghai-Tibetan Plateau. Soil moisture was identified as a key factor negatively affecting carbon stocks, and decreased soil moisture also indirectly impacted microbial biomass carbon through reducing plant biomass.