Cutting the Gordian knot of climate control on decomposition

Strong recent challenges of the long-standing paradigm that macroclimate predominantly controls decomposition questions the accuracy of climate change predictions. With a novel approach combining three experiments at continental scale, using 104 litter types in 194 plots in six major European forests, we show that the confusion around the macroclimate control on decomposition is mostly an experimental artefact. The relative role of decomposition drivers was incorrect when disrupting the natural context of locally-produced litter decomposing locally, with either a focus on litter characteristics neglecting microenvironmental context, or on environmental drivers neglecting local litter characteristics. Our data reaffirm macroclimate and its interaction with litter characteristics as predominant decomposition drivers. Conversely, standard litter types overrated microenvironmental control and failed to predict local decomposition of plot-specific litter. Our findings provide support for a strong macroclimate component in predictive decomposition models and call for cautious interpretation of data from experiments using standard litter types.