Effects of different plateau pika disturbance intensities on greenhouse gas fluxes in alpine meadows

Herbivore activities influence the rate of greenhouse gas emissions in grasslands. The plateau pika (Ochotona curzoniae) affects soil greenhouse gas emissions in alpine meadows through extensive disturbance of soil physicochemical properties and soil microorganisms by mowed plants, excretion of feces and urine, and digging up of the soil. This study set three alpine meadows as high-density (H), low-density (L), and control (CK) groups to compare the differences in greenhouse gas fluxes under different pika disturbance intensities. The effects of different pika densities on the soil’s physicochemical properties and greenhouse gas fluxes were analyzed. The CO₂ emission rate of alpine meadow soil in group H was 596.66 mg·(m²·h)⁻¹, which was significantly lower than that of group CK at 695.45 mg·(m²·h)⁻¹ (P < 0.05). The CO₂ emission rate was primarily influenced by the disturbance intensity of pikas, aboveground plant biomass, soil pH, and water content. The CH₄ uptake rate in alpine meadows was significantly higher in group H than that in group L −43.46, 4.92 mg·(m²·h)⁻¹; P < 0.05. The N₂O emission rate was significantly higher in both groups H and L −8.03 µg·(m²·h)⁻¹ and −2.39 µg·(m²·h)⁻¹, respectively than that in group CK −16.69 µg·(m²·h)⁻¹ (P < 0.05). The CH₄ and N₂O fluxes were mainly affected by soil nitrate nitrogen content, ammonium nitrogen content, pH, and water content. The findings indicate that the intensity of plateau pika disturbance is one of the factors affecting the greenhouse gas emission rate. Additionally, it is important to study the effect on the greenhouse gas emission rate of alpine meadow soils.