Fig. 3. The effects of different global change drivers (biodiversity and climate change) on plant litter decomposition in forest biomes.

a Comparison of the diversity effects (diversifying from mono- to multiple litter species) with the climatic effects based on annual mean temperature; b based on mean temperature of the wettest quarter; c precipitation of based on the driest quarter. The climatic effects were estimated using the dataset of a full reciprocal transplant experiment⁵⁰, which made it possible to remove the influences of plant litter traits and decomposers on decomposition rate; the effect size of the diversity effects (species-mixing effects) was estimated for the dataset of the present meta-analysis (for 57 forest studies that used leaf litter) and, based on temperature/precipitation required to change the effect size to the same magnitude as the diversity effects, the climate-equivalency of the diversity effects was estimated (turquoise bars). The two future projections (in 2070s) of climate changes (based on the CMIP5 RCP 2.6 and 8.5 scenario; means and standard deviations are shown as thick red bars and thin black error bars, respectively) are shown for the study locations of the present meta-analysis. See Table S1 for additional analyses using different subsets of the data.