Effects of temperature on soil organic carbon mineralization rate and enzyme kinetic parameters in temperate and subtropical forests.

We examined the effects of temperature on SOC mineralization rate (C_min) and enzyme kinetic parameters in soils of two different latitudinal forests, i.e., broad-leaved Korean pine forest in Changbai Mountain at higher latitude and evergreen broad leaved forest in Dinghu Mountain at lower latitude. The results showed that the soil C_min increased with temperature, and the C_min and ...) of the Changbai Mountain forest soil were higher than those of the Dinghu Mountain forest soil. The maximal rates of velocity (V_max) and the half saturation constant (K_m) of the Changbai Mountain forest soil were higher relative to the Dinghu Mountain soil for both soil β glucosidase (βG) and N-acetyl-β-D-glucosaminidase (NAG), but being opposite for catalytic efficiency (V_max/K_m). Both V_max and V_max/K_m of βG and NAG increased with the increase of incubation temperature, while K_m decreased, i.e., the affinity of enzymes to the substrate were increased. Inconsistent with the soil...), ...) and Q₁₀(K_m) of the soil βG were higher in Dinghu Mountain forest soil than those in the Changbai Mountain forest soil. The mechanisms underlying the effects of temperate variation on C_min and the enzyme kinetic parameters were different, and thus the temperature sensitivity of C_min and enzyme kinetic parameters should be considered differentially in the models of soil biochemical process. [ABSTRACT FROM AUTHOR]