Decoupling of soil carbon mineralization and microbial community composition across a climate gradient on the Tibetan Plateau

•Microbial community diversity and composition are sensitive to temperature.•Instantaneous microbial community is a poor predictor of SOC mineralization.•Microbial community is a proxy of substrate quality and availability.•Substate quality and availability are predominant regulators of SOC mineralization. Soil microbes drive soil organic carbon (SOC) mineralization. Because microbial groups differ in metabolic efficiency and respond differently to temperature variation, it is reasonable to expect a close association of SOC mineralization and its temperature sensitivity (Q10 which is defined as the factor of the change of soil carbon mineralization induced by 10 °C temperature increase) with microbial community diversity and composition. However, these relations have rarely been tested. Here, we conducted an incubation experiment to assess the temperature responses of microbial α diversity and the relative abundance of microbial r- and K-strategists in soils from a wide range of ecosystems across a climate gradient in the southeast Tibet. The results indicated that the instantaneous α diversity and the relative abundance of r- and K-strategists are significantly (P