Abstract: Litter input plays an important role in the balance of soil organic carbon (SOC) input and output. However, it remains unknown how warming influences the priming effect of litter input on SOC mineralization and temperature sensitivity. In this study, we added ¹³C-labled Chinese fir leaf litter to soils and incubated them at 15, 25 and 35 ℃ to compare the changes in total, litter-derived and soil-derived CO₂ release rates and accumulations, priming effects and temperature sensitivity (Q₁₀). We found that litter addition significantly increased total soil CO₂ release rates and accumulations, but the magnitude of such enhancement declined with increasing incubation temperature. Compared to control, litter addition stimulated the accumulation of soil-derived CO₂ and induced positive priming effects. The soil-derived and litter-derived CO₂ accumulations were increased with litter addition, but the priming effects declined with increasing incubation temperature. Litter addition decreased Q₁₀ values of total soil CO₂ release rate, and the Q₁₀ values of litter-derived CO₂ was lower than those of soil-derived CO₂. Our results imply that the effects of litter inputs on soil CO₂ release depended on temperatures, and that litter inputs can decrease the temperature sensitivity of soil CO₂ release rate.

Key words: leaf litter, soil respiration rate, priming effect, temperature sensitivity