Temperature sensitivity of soil organic carbon mineralization in different ecosystems

Soil organic carbon (SOC) mineralization is one of the important processes of carbon cycle in terrestrial ecosystems, and its response to global climate change is closely related to the source or sink issue of soil carbon dioxide emissions.Understanding the mechanism of SOC mineralization affected by temperature change in different ecosystems is essential for predicting green-house gas emission and SOC balance management.The SOC content and quality significantly vary under different ecological systems, which further influence the soil microbial community composition.These coupling effects directly or indirectly control the temperature sensitivity (Q₁₀) of SOC mineralization by biochemical processes; however, the results of these researches are not consistent.A positive correlation between soil organic carbon content and temperature sensitivity exists in different ecosystems, which indicates that the change of SOC content has the same trend with Q₁₀; while SOC quality and Q₁₀ are negatively correlated in different ecosystems, following the "carbon mass-temperature" hypothesis.Distinguishing the contribution of exogenous C decomposition and SOC mineralization to Q₁₀ would more accurately explain the changes of Q₁₀ at a certain extent.The response of temperature sensitivity to microbial characteristics is mainly in the changes of microbial community structure, and the change of dominant community often drives the change of Q₁₀.The SOC mineralization and its Q₁₀ are influenced by coupling effect of multiple factors rather than a unique factor.To clarify the interaction of the various factors involved in the carbon cycle and the effect on Q₁₀ values change among different ecological systems can provide a reference for the "carbon neutral".