Discoveries in microbial ecology
We are witnessing a new era in microbial ecology, spurred to a large extent by support from Bill Robertson and the Mellon Foundation. Just 15 years ago, researchers were emphasizing the need to confront the microbial “black box” in ecosystems. We knew that important ecosystem-level functions occurred within the black box, but we lacked knowledge of the mechanisms or microbial species involved. In fact, so many details were unknown, and the microbial community was considered so intractably complex, that research in this area was labeled very high risk. Thus, it was difficult to obtain funding. Fortunately, Mr. Robertson prioritized support of high-risk high-reward studies of the development of new techniques in this area. For example, the Mellon Foundation facilitated the application of high-throughput DNA sequencing to identify the diverse microbial species in the environment, isotope-based assessments of nutrient use by individual microbes in situ, nucleotide analog labeling to link microbial identity to function, and the adoption of nanotechnological techniques to trace the transformation of specific compounds within soil.
These approaches have revolutionized the field of microbial ecology. Now, instead of a black box, we know many of the microbial species in ecosystems, and how they respond to environmental conditions. We have a much better idea of the timescale over which they sequester and transform nutrients. We have established that microbial species vary widely in their functions in ecosystems, including which compounds they target during decomposition. Perhaps most promisingly, we are able to integrate this knowledge to predict how the various functional groups of microbes are likely to respond to environmental change, with consequences for ecosystem dynamics. These discoveries have led to the development of trait-based ecosystem models that incorporate microbial mechanisms and community dynamics, moving us beyond the black-boxed models of the past.