An Improved Parameterization Scheme for Soil Respiration Depending on Temperature and Moisture

Abstract Soil respiration () is a major component of the carbon flux released from terrestrial ecosystems into the atmosphere, thus substantially influencing the atmospheric carbon content and carbon–climate feedback. In Earth system models, is often assumed to increase exponentially with increasing temperature, whereas laboratory and field studies have demonstrated a unimodal temperature response, with respiration peaking at the optimum temperature (). In this study, an improved parameterization scheme based on the product of Gaussian functions, the dual Gaussian and macromolecular (DGMM) scheme, was proposed for temperature and moisture response. The scheme incorporates both a spatially varying , which is correlated with mean annual temperature, and a temperature‐dependent temperature sensitivity. The performance of the DGMM scheme was tested via the Community Land Model with Biogeochemistry version 5 (CLM5‐BGC) at seven sites spanning boreal to tropical climate zones. The results indicated that the scheme reduced bias in simulated values by approximately 20% compared with original CLM5‐BGC scheme. It particularly mitigated winter overestimation and summer underestimation in boreal and temperate zones while suppressing summer overestimation in the tropics. The adoption of this scheme can contribute to improving the estimation and prediction of terrestrial carbon budgets in ESMs.