Moorhead, Daryl L. and John C. Priscu. The McMurdo Dry Valleys comprise one of the coldest and driest ecosystems on our planet. Despite these extremes, a variety of life exists in their soils, streams, lakes, glacial and lake ice meltwater pools, and rocks. The biota generally are dominated by prokaryotes, with eukaryotes restricted to the less stressful sites.
Key conditions limiting life are liquid water and energy.
In the presence of liquid water, radiant energy drives photoautotrophic production that provides heterotrophic communities with a carbon and energy supply. Spatio-temporal linkages between landscape components augment productivity of some communities and permit others to exist in places and at times that otherwise would be impossible. For example, organic matter supporting some soil food webs originates in lakes and streams. Owing to tight spatio-temporal linkages, which we believe are necessary for the existence of life in extreme environments, ecological research in the McMurdo Dry Valleys must extend beyond isolated communities and focus on integrating system components. Herein we summarize existing knowledge of the McMurdo Dry Valley ecosystem emphasizing results from other papers in this volume.