关键词: 啮齿动物扰动, 高寒草甸, 生态系统呼吸, 土壤温度, 温度敏感性

Abstract: Aims Rodent disturbances significantly affect the respiration of alpine meadow ecosystems. However, the severe scarcity of field measurements has critically limited our understanding of how widespread rodent disturbances influence alpine meadow Re flux dynamics, particularly given that existing observations remain extremely sparse and predominantly confined to the growing season. Conducting year-round, high-resolution in situ Re flux measurements is therefore essential to assess the impacts of rodent bioturbation on soil Re emissions in alpine meadow and elucidate the underlying mechanisms. Methods This research utilized the static chamber-gas chromatography method to perform a year-long investigation spanning October 2022 to October 2023, examining the variations in ecosystem respiration flux between two heterogeneous land types: healthy meadow (HM) and zokor mounds patches (ZM), located in the northeastern Tibetan Plateau. Additionally, the study sought to elucidate the potential mechanisms underlying ecosystem respiration emissions. Important findings Following disturbance, the annual cumulative Re flux at ZM (5906.03 ± 209.20 kg C ha-1 yr-1) decreased significantly by 27.60% (p < 0.05) compared to HM (8157.52 ± 305.30 kg C ha-1 yr-1), with reductions of 28.64% and 16.39% observed during the growing and non-growing seasons, respectively. The temperature sensitivity (Q10) of HM and ZM exhibited minimal differences at annual (6.11 ± 0.31 vs. 5.78 ± 0.41) and growing-season (4.13 ± 0.85 vs. 4.10 ± 0.61) scales. However, HM demonstrated significantly higher Q10 values (11.90 ± 1.80) than ZM (4.76 ± 1.00) during the non-growing season (p < 0.05). Seasonal Re variation patterns remained consistent across treatments and were not exclusive to post-disturbance conditions. Soil temperature and soil water content exerted combined effects as primary driving factors, with soil temperature explaining 59.7-85.3% of Re emissions. This study demonstrates that rodent disturbance significantly suppresses alpine meadow ecosystem respiration, providing critical insights for grassland carbon cycle modeling and ecosystem management.

Key words: rodent disturbance, alpine meadow, ecosystem respiration, soil temperature, temperature sensitivity