Carbon inputs regulate the temperature sensitivity of soil respiration in temperate forests

Litter and root activities may alter the temperature sensitivity (Q 10 ) of soil respiration. However, existing studies have not provided a comprehensive understanding of the effects of litter and root carbon inputs on the Q10 of soil respiration in different seasons. In this study, we used the trench method under in situ conditions to measure the total soil respiration (R total ), litter-removed soil respiration (R no-litter ), root-removed soil respiration (R no-root ), and the decomposition of soil organic matter (i.e., both litter and root removal; R SOM ) in different seasons of pioneer ( Populus davidiana Dode) and climax ( Quercus liaotungensis Mary) forests on the Loess Plateau, China. Soil temperature, soil moisture, litter biomass, fine root biomass, litter carbon, and root carbon were analyzed to obtain the drive mechanism of the Q 10 of soil respiration in the two forests. The results showed that the Q 10 of soil respiration exhibited seasonality, and the Q 10 of soil respiration was higher in summer. The litter enhanced the Q 10 of soil respiration considerably more than the root did. Soil temperature, soil moisture, fine root biomass, and litter carbon were the main factors used to predict the Q 10 of different soil respiration components. These findings indicated that factors affecting the Q 10 of soil respiration highly depended on soil temperature and soil moisture as well as related litter and root traits in the two forests, which can improve our understanding of soil carbon—climate feedback in global warming. The results of this study can provide reference for exploring soil respiration under temperate forest restoration.