Non-additive interactions between grazing and zokor bioturbation drive soil carbon dynamics in alpine meadows on the qinghai-tibet plateau

Alpine meadows on the Qinghai-Tibet Plateau hold important soil carbon pools sensitive to biotic disturbances. This study examined individual and combined effects of grazing and plateau zokor bioturbation on soil organic carbon, inorganic carbon, total carbon, and total nitrogen across depths and seasons. Grazing increased organic carbon and nitrogen while reducing inorganic carbon. Zokor activity caused seasonal vertical redistribution of carbon and nitrogen. Combined disturbances showed significant non-additive effects: synergistic suppression of inorganic carbon and antagonistic effects on organic carbon and nitrogen. These results improve understanding of disturbance interactions and support sustainable carbon management in alpine meadows.