Frontiers in biogeochemistry: from microbes to ecosystems to Earth

Microorganisms influence the composition of the atmosphere, the cycling of elements within and through ecosystems, the functioning of agricultural ecosystems on which humans depend, and human health. Microorganisms are also the most metabolically flexible, and the most taxonomically and evolutionarily diverse organisms on Earth. Yet deciphering how that diversity imprints on the processes they influence at larger scales has proven challenging, because of the overwhelming complexity of microbial communities, and because of the difficulty of quantifying how microbial taxa assimilate and transform elements in the environment. In this talk, I will discuss new approaches that blend traditions from microbial ecology and biogeochemistry to explore how the diversity and physiology of microorganisms could shape ecosystem biogeochemistry and how it responds to global environmental change. The talk will focus on soil microbial ecology, but will also touch on microbial ecology in agriculture and in human health. Historically, the diversity, complexity, and intractability of microbial ecosystems has relegated their study to either a reductionist descriptive tradition in microbial ecology or to a simplistically quantitative one in biogeochemistry. Yet, new ideas and tools are poised to push microbial ecology forward to a point where it can more meaningfully integrate with ecological fields at larger scales, from ecosystems to the globe.