Temperature sensitivity of soil respiration is affected by prevailing climatic conditions and soil organic carbon content: A trans-China based case study

Abstract Understanding the spatial variation of temperature sensitivity (i.e. Q 10 ) of soil respiration ( R s ) and its controlling factors, is critical to improve the precision of carbon budget estimations at regional scales. In this study, data from 2–3 continuous years of R s measurements over 15 ecosystems of ChinaFLUX were summarized to analyze the response of R s to soil temperature. Moreover, we improved our dataset by collecting previously published Q 10 values from 34 ecosystems in China. The ecosystems studied were located in the main climatic zones of China, spanning from alpine via temperate to tropical. Spatial variations of Q 10 and its controlling factors were analyzed. The results showed that soil temperature at a 5 cm depth satisfactorily explained the seasonal variations in R s of the 15 ChinaFLUX ecosystems ( R 2 varying from 0.37 to 0.83). Based on the overall data, the Q 10 values of R s in China ranged from 1.28 to 4.75. The spatial variations in Q 10 were primarily determined by soil temperature during measurement periods, soil organic carbon (SOC) content, and ecosystem type. Ecosystems in colder regions and with higher SOC content had relatively higher Q 10 values. Moreover, ecosystems of different vegetation types showed different Q 10 values. A temperature- and SOC-dependent function for Q 10 is suggested, which could be a valuable reference for improving the regional-scale models of R s and ecosystem carbon cycles.