Abstract
How do microbial communities shape soils, oceans, and food webs? Current methods allow us to describe their diversity and abundance and to identify networks of interactions. However, they struggle to determine the mechanisms and functions that link these microorganisms to ecosystems. Soils illustrate this complexity: bacteria, archaea, fungi, protists, animals, and plant roots form extremely diverse communities there, whose interactions contribute to the functioning and stability of the whole. Yet our experimental approaches often remain reductionist and limited to interactions between two partners. The challenge now is to go beyond simply determining who is there, and instead understand who is with whom, how, and for what purpose. What a vast undertaking!
