Warming Changed Soil Respiration Dynamics of Alpine Meadow Ecosystem on the Tibetan Plateau

• Published in: Journal of Environmental & Earth Sciences
• Main Authors: Wang, Junfeng, Yuan, Ziqiang, Wu, Qingbai, Rafique, Rashad
• Format: Article in Journal/Newspaper
• Language: English
• Published: BILINGUAL PUBLISHING CO. 2019
• Subjects: Soil respiration; Alpine meadow; Experimental warming; Open-top chamber; permafrost
• Online Access: https://ojs.bilpublishing.com/index.php/jees/article/view/511; https://doi.org/10.30564/jees.v1i2.511

Alpine meadow system underlain by permafrost on the Tibetan Plateau contains vast soil organic carbon and is sensitive to global warming. However, the dynamics of annual soil respiration (Rs) under long-term warming and the determined factors are still not very clear. Using opentop chambers (OTC), we assessed the effects of two-year experimental warming on the soil CO2 emission and the Q10 value (temperature sensitivity coefficient) under different warming magnitudes. Our study showed that the soil CO2 efflux rate in the warmed plots were 1.22 and 2.32 times higher compared to that of controlled plots. However, the Q10 value decreased by 45.06% and 50.34% respectively as the warming magnitude increased. These results suggested that soil moisture decreasing under global warming would enhance soil CO2 emission and lower the temperature sensitivity of soil respiration rate of the alpine meadow ecosystem in the permafrost region on the Tibetan Plateau. Thus, it is necessary to take into account the combined effect of ground surface warming and soil moisture decrease on the Rs in order to comprehensively evaluate the carbon emissions of the alpine meadow ecosystem, especially in short and medium terms.