Kirschbaum, M.U.F.
(2006). The temperature dependence of organic-matter decomposition – still a
topic of debate. Soil Biology and Biochemistry 38: 2510-2518.
Abstract.
The temperature dependence of organic matter decomposition is of
considerable ecophysiological importance, especially in the context of possible
climate-change feedback effects. It effectively controls whether, or how much,
carbon will be released with global warming, and to what extent that release of
carbon constitutes a dangerous positive feedback effect that leads to further
warming.
The present paper is an invited contribution in a
series of Citation Classics based on a review paper of the temperature dependence
of organic matter decomposition that was published in 1995. It discusses the
context and main findings of the 1995 study, the progress has been made since
then and what issues still remain unresolved.
Despite the continuation of much further experimental
work and repeated publication of summary articles, there is still no scientific
consensus on the temperature dependence of organic matter decomposition. It is
likely that this lack of consensus is largely due to different studies
referring to different experimental conditions where confounding factors play a
greater or lesser role. Substrate availability is particularly important. If it
changes during the course of measurements, it can greatly confound the derived
apparent temperature dependence. This confounding effect is illustrated through
simulations and examples of experimental work drawn from the literature. The
paper speculates that much of the current disagreement between studies might
disappear if different studies would ensure that they are all studying the same
system attributes, and if confounding factors were always considered and, if
possible, eliminated.
Keywords: carbon; climate change; soil respiration; substrate; temperature sensitivity.