Metamicrobiome-driven homeostasis of nutrient recycling

Carbon and nutrient recycling by free-living microbial decomposers and fire - two key recycling pathways - are highly sensitive to climatic variation. However, mutualistic associations of microbiomes with plants and animals cause previously underestimated environmental buffering effects. This close cooperation between small and large organisms solves a fundamental allometric trade-off between mass-specific metabolic capacity (decreasing with body size) and homeostatic capacity (environmental buffering; increasing with body size), allowing the combination of the best of both worlds along the body mass spectrum from microbes to elephants. A diverse metamicrobiome, where plant- and animal-associated microbiomes complement the free-living microbiome, consequently increases ecosystem homeostasis of recycling rates in a variable environment. We argue for better integration of this fundamental ecological process in predicting the consequences of current accelerated environmental change.