Collaborative Research: MO: Forces Driving Microbial Community Diversity and Composition in Humic Lakes

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

Microbes are responsible for most of the carbon and nutrient cycling in freshwater lakes, and influence both local water quality and global carbon budgets. However, it is not currently possible to predict which types of microbes will be found in a particular lake at a particular time, or to predict how a microbial community would respond to environmental change. Microbial biologists need to learn more about how microbes in lakes assemble into communities, the role of drivers such as competition, predation, resource availability, disturbance, and natural selection in shaping these assemblages. This project addresses the following overarching question: What forces organize microbial communities in humic lakes? Microbes and their communities respond to many forces acting at different spatial and temporal scales, and the effect of these forces can be observed at the level of both communities and populations. An interdisciplinary team of microbiologists, ecologists, engineers, and limnologists will use a suite of molecular tools and genomics to investigate (1) Interactions between bacteria and phytoplankton in the surface layers of lakes; (2) Changes in microbial communities resulting from water column disturbances such as thermal stratification and seasonal mixing and (3) The role of evolutionary processes in shaping individual microbial populations within and among lakes. The results of this work will allow us to better explain and ultimately predict the composition and dynamics of microbial communities and populations in freshwater lakes. This project will not only advance our understanding of the microbial ecology of humic lakes, but of microbial ecology and biodiversity in a broader context. The research approach is structured within an ecological framework and reflect urgent questions in the field of microbial biology. To enhance the broader impacts of the work, the investigators will engage in outreach activities coordinated with the following organizations; the NTL-LTER SchoolYard Science program which promotes inquiry-based learning through workshops for high-school teachers; the Center for Biology Education which is developing a virtual professional development resource for middle and high school science and mathematics teachers; the UW-Madison PEOPLE program which organizes summer courses for underrepresented high-school students; the NSF-funded Center for the Integration of Teaching, Research, and Learning which promotes professional development of graduate students, post-docs, and faculty. The research team will continue to leverage these existing programs to show the general public how freshwater microbes are key components of lake ecosystems, impacting water quality and nutrient cycling in profound ways.