Paper No. 9
Presentation Time: 9:00 AM-6:00 PM


RYTEL, Alex L., 1574 Worthington St, Columbus, OH 43201, HERBEI, Radu, Department of Statistics, The Ohio State University, Columbus, OH 43210, LYONS, W. Berry, Byrd Polar Research Center and School of Earth Sciences, The Ohio State University, Columbus, OH 43210, PRISCU, John C., Department of Land Resources and Environmental Sciences, Montana State University, P.O. Box 173120, Bozeman, MT 59717-3120 and MCKNIGHT, Diane M., Institute for Arctic and Alpine Research, University of Colorado, 1560 30th Street, Boulder, CO 80309,

The McMurdo Dry Valleys of Antarctica constitute a large and significantly ice free area of Antarctica at 78 degrees south latitude. The area is under desert conditions and contains several lakes fed by glacial melt water 1 to 4 months out of the year. Over the past 19 years data have been gathered on the lakes located in Taylor Valley, Antarctica as part of the McMurdo Valley Long-Term Ecological Research program (MCM-LTER). This study is part of a larger study that seeks to understand the impact of climate on the biological processes in all the ecosystems within Taylor Valley, including the lakes. These lakes are stratified, closed-basin systems and are permanently covered with ice. Each lake plays host to a variety of planktonic and benthic organisms that live on the edge of survival in this extreme environment.

In this ecosystem subtle changes in physical properties can result in large fluctuations in biological activity. The work presented here focuses on one of the three large lakes in Taylor Valley, Lake Fryxell, which is fed by 13 streams. Previous work has demonstrated that biological activity in the lakes is primarily driven by ice thickness and the input of photosynthetically active radiation (PAR). Stream input of nutrients is also thought to be a significant factor in lake productivity. We use a statistical approach to link the physical, chemical, and biological processes within the lake and the streams that feed it. In our statistical approach we use light, phosphorus, nitrogen, and other lake parameters as explanatory variables for biological production and biomass profiles, and attempt to link the physiochemical properties of the lake to biological changes within the lake.