Calorespirometry: A novel tool to assess the effect of temperature on soil organic matter decomposition

Abstract The temperature sensitivity of soil carbon decomposition is a subject receiving much attention, but is still limited by insufficient methodologies. It is important to provide new methods and alternative indices connecting soil carbon mineralization with temperature. Calorespirometry constitutes an alternative, but its usefulness and sensitivity for these studies has not yet been tested. We present some preliminary results showing how calorespirometry detects the response of soil biodegradation to increasing temperature directly and in real time. Results show an immediate response of rates to increasing temperature from 18 to 35 °C. The evolution of heat and CO 2 rates followed the Arrhenius model. The method permitted determination of Q 10 values and activation energies. The calculation of the calorespirometric ratios showed respiration of carbohydrates was the main component of the soil microbial basal metabolism along the entire temperature scan.