The Temper atur e Sensitivity of Soil Respir ation
土壤呼吸的温度敏感性

A growing body of literature sheds new light on the importance of the temperature sensitivity(Q10) of soil respiration for understanding terrestrial carbon cycling.It has been well known that small changes in Q10 value will have great influence on soil CO2 efflux,due to its nonlinear response to temperature.Because most of large-scale carbon cycle models are based on the temperature sensitivity,the accurate determination of Q10 value is essential in estimating carbon efflux in terrestrial ecosystems and predicting future climate change.Unfortunately,this value remains uncertain yet.A fixed Q10 of 2.0 has been widely used in modeling leaf-to ecosystem-scale respiration responses to temperature,until several recent studies suggest that Q10 value is not constant during a year,but tends to decrease with increasing temperature and decreasing soil moisture.A fixed Q10 used in empirical or processes-based models,therefore,can result in a greatly over-or under-estimated soil respiration,due to the variability of Q10 value.More insight information in the relationship between Q10 and controlling factors is vital for accurately estimating soil respiration and for developing management strategies to improve soil fertility and to increase C sequestration in soil. In this paper,we reviewed recent advances and hotspots in Q10 research,especially focused on the responses of resistant and labile carbon to temperature.We further reviewed why Q10 value is so variable and explained this phenomenon based on the Michaelis-Menten kinetics.In addition,we reviewed how soil temperature and moisture influence substrate availability and enzymes activity and hence influence temperature sensitivity of soil respiration.