Abstract: Soil respiration (R_s) comprises autotrophic (R_a) and heterotrophic (R_h) respiration. The difference in temperature sensitivity (Q₁₀) between R_a and R_h is still under debate. Rhizosphere priming effect (RPE) plays an important role in affecting the temperature sensitivity of R_h, which makes the issue more complex. Here we used the ¹³C natural abundance method by planting Acer mono (C₃ plant) in microcosms with maize soil (soil with cultivation of C₄ maize for 23 years) to investigate the responses of R_a and R_h to temperature change and the role of RPE. An overall negative RPE was observed in the growing season, which reduced R_h and its Q₁₀ value by 34.3% and 27.0%, respectively. The Q₁₀ value of R_a (3.89) was 2.5 times higher than that of R_h (1.51). Our results highlight the importance of plant roots in regulating the response of R_s to temperature, which should be considered in models of soil respiration in the future.

Key words: life-form functional group, leaf trait, Stipa krylovii steppe., grazing gradient