The influence of soil communities on the temperature sensitivity of soil respiration

Soil respiration represents a major carbon flux between terrestrial ecosystems and the atmosphere, and is expected to accelerate under climate warming. Despite its importance in climate change forecasts, however, our understanding of the effects of temperature on soil respiration (R_S) is incomplete. Using a metabolic ecology approach we link soil biota metabolism, community composition and heterotrophic activity to predict R_S rates across five biomes. We find that accounting for the ecological mechanisms underpinning decomposition processes predicts climatological R_S variations observed in an independent dataset (n = 312). The importance of community composition is evident because without it R_S is substantially underestimated. With increasing temperature, we predict a latitudinal increase in R_S temperature sensitivity, with Q₁₀ values ranging between 2.33 ± 0.01 in tropical forests to 2.72 ± 0.03 in tundra. This global trend has been widely observed, but has not previously been linked to soil communities.