Progress in understanding the temperature sensitivity of soil organic carbon decomposition

Soil is the largest organic carbon reservoir in terrestrial ecosystems, and even subtle changes in the rate of soil organic carbon (SOC) decomposition can markedly alter atmospheric CO2 concentration, thereby influencing the trajectory of climate change. In recent years, with ongoing global warming, increasing attention has been paid to the temperature response of SOC decomposition and its underlying mechanisms. This paper provides a systematic review of advances in the temperature sensitivity of SOC decomposition, with a particular focus on biotic and abiotic controls, horizontal spatial patterns, vertical profile heterogeneity, and the dynamic responses and adaptive processes of SOC decomposition to temperature change. Synthesizing current evidence, we show that the temperature sensitivity of SOC decomposition exhibits pronounced spatiotemporal heterogeneity and is jointly regulated by microbial processes, substrate properties, and physico-chemical protection mechanisms. Future research should further quantify the spatiotemporal variability of SOC decomposition temperature sensitivity and its drivers, and explicitly incorporate microbially mediated processes into terrestrial carbon cycle models, in order to improve predictions of soil carbon-climate feedbacks and provide a stronger scientific basis for achieving carbon neutrality targets.