Diversity, stability and functioning of the soil microbiome

A major challenge for advancing our understanding of the functional role of highly complex soil microbial communities is to systematically link changes in their structure and functioning to biogeochemical cycles under realistic scenarios of global change. This is a formidable challenge: not only does it require a step change in our understanding of the factors that shape soil microbial communities and their functioning, but also it requires new knowledge of the ecological and genetic mechanisms that underpin its stability, or ability to resist and recover from abiotic perturbations associated with global change. By embracing technological and theoretical developments in microbial ecology, SoilResist will make a major step forward in our understanding of the mechanisms that underpin the resistance and resilience of soil microbial communities and their functioning to natural and anthropogenic perturbations. Specifically, I seek to develop a novel mechanistic understanding of the factors that underpin the resistance and resilience of complex soil microbial communities and their functioning to different types of anthropogenic perturbations, and, for the first time, identity critical thresholds for abrupt transitions of microbial communities to alternative states and consequences for soil functioning. My overarching hypothesis is that the stability of microbial functions, in terms of their capacity to resist and recover from a pulse perturbation caused by climate extremes, is determined by microbial functional diversity, based on range and relative abundance of microbial traits. I also hypothesize that shifts in microbial functional diversity resulting from press perturbations erode the capacity of soil microbial communities to buffer climate-related pulse perturbations, rendering them more vulnerable to an abrupt transition to alternative taxonomic and functional state with negative consequences for soil functioning.