The plant carbon pool, an important source of the grassland soil carbon pool, plays a crucial role in carbon cycling and climate regulation. Small subterranean herbivores, such as the plateau zokor (Eospalax baileyi), significantly influence the plant carbon pool through their extensive foraging activities in grassland ecosystems. This study focuses on the plateau zokor, an endemic subterranean herbivore of the Qinghai-Tibet Plateau, which inhabits various types of alpine grasslands: alpine meadows, alpine steppes, and alpine meadow steppes. Using in-situ paired sampling, we analyzed the effects of foraging tunnel disturbances on the plant carbon pool and identified key factors influencing the plant carbon pool in both tunnel and non-tunnel quadrats. Our results indicate that foraging tunnel disturbances significantly reduce both the aboveground and belowground plant carbon pools, with the pronounced impact in alpine steppes, followed by alpine meadow steppes and alpine meadows. The ratio of belowground to aboveground plant carbon pools also declined across the three alpine grassland types, indicating a greater impact on belowground pools. Key factors such as soil moisture, microbial biomass carbon, and organic carbon levels were crucial in influencing the plant carbon pool changes. These findings suggest the importance of considering the impacts of small subterranean herbivores when assessing carbon pools in alpine grassland ecosystems and provide a scientific basis and practical methods for future management and restoration of plant carbon pools.