Moreover, both warmed and control treatments exhibited a similar temperature response of soil respiration, indicating that adaptation in terms of temperature sensitivity was absent. Carbon dioxide concentration measurements within the profiles are supporting these findings.

The increased soil respiration occurred although vegetation productivity in the warmed treatment was not higher than in the control plots. These findings strongly contrast with current soil carbon modeling concepts, where carbon pools decay according to first-order kinetics, and thus a depletion of labile soil carbon pools leads to an apparent down-regulation of microbial respiration (Knorr et al 2005 Nature 433 298–301).

Consequently, the potential for positive climate carbon cycle feedback may be larger than represented in current models of soil carbon turnover.

This forms the abstract of an article published in Environmental Research Letters. The full article is available here.