Current Research

- Studies of deep ice cores from the Arctic and Antarctic
- Environmental Biofilms
- Dissolved organic matter (DOM) dynamics

My research interests revolve around the organization of microbial communities in relation to their physical environment and the processing of nutrients and organic matter. The permanently ice covered lakes, streams and glaciers of the McMurdo Dry Valleys provide a unique setting in which to study microbial interactions. Our research on these lakes has examined the impact of thermodynamics on a variety of ecologically important redox reactions and how humic substances act as acceptors and shuttles in electron transport reactions. We have also conducted the first studies of biofilm communities in these lakes, showing them to be hotspots of activity.

Life exists in the liquid water phases of ice, and is dependent upon dissolved nutrients and carbon sources. DOM provides the major energy supply to heterotrophic microorganisms. The contribution of DOM to global carbon budgets, including potential storage in ice, and how this stored DOM responds to enhanced UV and climate change is only beginning to be addressed. The connection between ice-bound DOM and climate change is important because frozen environments comprise 25% of the Earths surface and the carbon reservoir in ice is equivalent to that in all of the Earth’s freshwaters.

Once believed to be devoid of life, closer observations of glacial ice have revealed microhabitats teeming with life. Cryoconite holes are essentially biofilm communities entombed in ice on the glacier surface. We believe that our work will contribute to the understanding of how life survived through proposed global-glaciation events on our planet. Cryoconite holes provide a modern day analog of a possible refuge for microbial life during these “Snowball Earth” events. In addition, our studies set the stage for future investigations of life on other icy planets and moons.

Recent Publications

J. Priscu and C. M. Foreman (2009). Lakes of Antarctica. In Encyclopedia of Inland Waters. G. Likens (ed.) pp. 555-566. Tranter, M., L. Bagshaw, A. Fountain and C. M. Foreman. (2009). Glaciers. In Astrobiological Analogues: Life in Antarctic Deserts and other Cold Dry Environments. P. Doran, B. Lyons and D. McKnight (eds.). Christner, B. C., C. E. Morris, C. M. Foreman, R. Cai, and D. C. Sands (2008), Ubiquity of Biological Ice Nucleators in Snowfall, Science, 319, 1214. Christner, B.C., Cai, R., Morris, C.E., McCarter, K.S., Foreman, C.M., Skidmore, M.L., Montross, S.N., Sands, D.C. (2008), Geographic, seasonal, and precipitation chemistry influence on the abundance and activity of biological ice nucleators in rain and snow, Proceedings of the National Academy of Science, 2008, 105(48):18854-18859. Christner, B. C., M.L. Skidmore, J. C. Priscu, M. Tranter and C. Foreman (2008). Bacteria in Subglacial Environments. In Psychrophiles: From Biodiversity to Biotechnology. R. Margesin, F. Schinner, J-C Marx and C. Gerday (eds.). Springer-Verlag. pp. 51-71. Priscu, J. C., S. Tulaczyk, M. Studinger, M. C. Kennicutt II, B. C. Christner, and C. Foreman (2008). Antarctic Subglacial Water: Origin, Evolution and Ecology. In Polar Lakes and Rivers, W. Vincent and J. Laybourn-Parry (eds.), Oxford Press. pp. 119-136. Foreman, C. M., B. Sattler, J. A. Mikucki, D. L. Porazinska and J. C. Priscu (2007). Metabolic Activity and Diversity of Cryoconites in the Taylor Valley, Antarctica. J. Geophys. Res. Biogeosciences, 112, G04S32, doi:10.1029/2006JG000358.