A new incubation and measurement approach to estimate the temperature response of soil organic matter decomposition

A reliable and precise estimate of the temperature sensitivity (Q 10) of soil organic matter (SOM) decomposition is critical to predict feedbacks between the global carbon (C) cycle and climate change. In this study, we first summarize two commonly used approaches for estimating Q 10 ( Approach A : constant temperature incubation and discontinuous measurements, CDM model; Approach B : varying temperature incubation and discontinuous measurements, VDM model). We then introduced a newly developed approach ( Approach C, VCM model) that combines rapidly varying temperature incubations and continuous measurements of SOM decomposition rates (R s) that may be more realistic and suitable for Q 10 estimation, especially for large scale estimation. Then, we conducted a 26-day incubation experiment using three different soils to compare the performance of these three approaches for estimating Q 10 using R 2 and P-values as indicators. Our results demonstrate that the fitting goodness of the exponential model was consistently higher for Approach C , with higher R 2 values, lower confidence intervals, and lower P-values in almost all cases compared with Approaches A and B . Furthermore, results showed that Approaches A and B underestimated the Q 10 value by 9.5–13% and 2.9–5.7%, respectively, in three different soils throughout the entire incubation period. Compared with traditional commonly used methods, the newly developed Approach C (VCM model) provides a more accurate and rapid estimation of the temperature response of SOM decomposition and can be used for large-scale estimation of Q 10.