TEMPERATURE-DEPENDENCE OF ORGANIC-MATTER DECOMPOSITION - A CRITICAL-REVIEW USING LITERATURE DATA ANALYZED WITH DIFFERENT MODELS

The literature was reviewed regarding laboratory incubation studies wh ere C mineralization was measured. Experiments were select-ed in which the same substrate was incubated at least at two different temperatur es and where time-series were available with at least four measurement s for each substrate and temperature. A first-order one-component mode l and a parallel first-order two-component model were fitted to the CO 2-C evolution data in each experiment using a least-squares procedure. After normalising for a reference temperature, the temperature coeffi cient (Q(10)) function and three other temperature response functions were fitted to the estimated rate constants. The two-component model c ould describe the dynamics of the 25 experiments much more adequately than the one-component model (higher R-2, adjusted for the number of p arameters), even when the rate constants for both were assumed to be e qually affected by temperature. The goodness-of-fit did not differ bet ween the temperature response models, but was affected by the choice o f the reference temperature. For the whole data set, a Q(10) of 2 was found to be adequate for describing the temperature dependence of deco mposition in the intermediate temperature range (about 5-35 degrees C) . However, for individual experiments, Q(10) values deviated greatly f rom 2. At least at temperatures below 5 degrees C, functions not based on Q(10) are probably more adequate. However, due to the paucity of d ata from low-temperature incubations, this conclusion is only tentativ e, and more experimental work is called for.