Does the temperature sensitivity of decomposition vary with soil organic matter quality?
1Laboratory of Forest Ecology, Universitá della Tuscia, I-01100 Viterbo, Italy
2Potsdam Inst. for Climate Impact Research, Telegrafenberg C4, D-14473 Potsdam, Germany
3Soil Fertility and Plant Nutrition, SLU, Department of Soil Sciences, P.O.Box 7014, 75007 Uppsala, Sweden
4Lab. des Sciences du Climat et de l’Environnement, LSCE, 91191, Gif sur Yvette, France
5Max-Planck Institut für Biogeochemie, PO Box 100164, 07701 Jena, Germany
Abstract. Knorr et al. (2005) concluded that soil organic carbon pools with longer turnover times are more sensitive to temperature. We show that this conclusion is equivocal, largely dependent on their specific selection of data and does not persist when the data set of Kätterer et al. (1998) is analysed in a more appropriate way. Further, we analyse how statistical properties of the model parameters may interfere with correlative analyses that relate the Q10 of soil respiration with the basal rate, where the latter is taken as a proxy for soil organic matter quality. We demonstrate that negative parameter correlations between Q10-values and base respiration rates are statistically expected and not necessarily provide evidence for a higher temperature sensitivity of low quality soil organic matter. Consequently, we reckon it is premature to conclude that stable soil carbon is more sensitive to temperature than labile carbon.