EAPSI: Searching for links between protozoan communities and changes in nutrient availability over time in Antarctic Dry Valley soils

Thompson Andrew R, Provo UT

Investigators

Abstract

Many protozoa have been shown to play a major role in regulating metabolism in bacteria, which is central to nutrient cycling in virtually all ecosystems on Earth. All organisms depend on these cycling processes, and thus protozoa are integral to the continual existence of life on earth. Understanding which species of protozoa play which role in nutrient cycling will result in more accurate environmental models, a greater ability to manipulate microbial communities in bioreactors, an improved understanding of ecosystem engineering, and aid projects aimed at increasing agricultural productivity. Because the ecology of microbial communities is usually highly complex, this project will use soils from the relatively simple ecosystems of the McMurdo Dry Valleys (MDV) in Antarctica to explore the relationship between protozoan communities and nutrient cycling. Dr. Craig Cary at the University of Waikato in Hamilton, New Zealand is accomplished at characterizing microbial communities in Antarctic environments and has access to unique microcosms that will be essential for this project. Antarctic soil will be incubated in artificial soil microcosms for an extended period of time to capture the dynamics of a community in nature. Changes in protozoan and bacterial community structure will be subsampled and sequenced at prescribed intervals. Soil geochemistry and nutrient concentration will be analyzed to link nutrient availability to community composition. To provide context for the incubation experiment, environmental DNA from diverse locations and a range of soil chemistries will also be target-sequenced. Significance of bacterial and protozoan species correlation will be inferred using multidimensional scaling (MDS). These data will elucidate habitat suitability models for MDV protozoa, clarifying which elements of the community are driven by abiotic or biotic constraints, respectively. This NSF EAPSI award is funded in collaboration with Royal Society of New Zealand.