Plant carbon removal affects monthly temperature sensitivity of soil respiration during growing season in three typical plantations in the Loess Hilly Region, China

The temperature sensitivity of soil respiration (Q10) is primarily related to annual climate parameters and soil properties in regional models. Changes in climate and soil properties influence plant carbon (C) inputs, which in turn alter Q10 during the growing season. However, the magnitude of this influence remains uncertain. Herein, using meteorological data from small stations and field experiments across three plantations (Robinia pseudoacacia, Caragana korshinskii, and Bothriochloa ischaemum), we investigated the variations in Q10 with respect to the following four treatments: litter removal, root trenching, root trenching and litter removal, and a control group, for 6 months. We found that R. pseudoacacia had the highest relative contribution to atmospheric C release, followed by C. korshinskii, and then B. ischaemum. The Q10 components were month-dependent under C remove in three typical plantations. Litter removal significantly reduced Q10, but the effect of root trenching differed according to the plantation. The variations of Q10 with C removal were primarily controlled by interacting air temperature, air pressure, potential hydrogen, root C, root biomass, soil organic C, and relative humidity, explaining the variations of 81.29-99.33 % (R. pseudoacacia plantation), 89.1-99.76 % (C. korshinskii plantation), and 99.34-99.74 % (B. ischaemum) of the variation in Q10; among them, the cumulative contribution of climate (soil temperature, air pressure, and relative humidity), plants (root C and root biomass), and soil properties (potential hydrogen and soil organic C) accounted for 34.84 %-61.93 %, 12.15 %-32.75 %, and 8.07 %-32.11 %, respectively. These findings demonstrate that C removal variations influenced the Q10, whereas Q10 was also month-dependent. Overall, we recommend that the role of Q10 in the growing season should carefully consider C removal into the soil to improve the biosphere-atmosphere C exchange model in the context of climate change.