Ecosystem Dynamics in a Polar Desert – The McMurdo Dry Valleys, Antarctica v72

Published by the American Geophysical Union as part of the Antarctic Research Series, Volume 72.

The McMurdo Dry Valleys of southern Victoria Land comprise the largest ice?]free expanse (about 4000 km2) on the Antarctic continent. Research in this region began during British expeditions of the early 1900's and has yielded much information on specific physical, chemical and biological features of the area. Only recently have scientists begun to view the region as an integrated system which includes dynamic interactions among biotic and abiotic components of the environment. The McMurdo Dry Valleys represents the coldest and driest desert on this planet. Photoautotrophic and heterotrophic microorganisms that are intimately linked with the presence of liquid water and nutrients dominate the biological assemblages. Owing to the low average temperature (-20 Degrees C) in the region, liquid water is a rare commodity that often exists for a short period only and occurs in many inconspicuous places. It is now clear that the presence of liquid water produces a cascade of tightly coupled events that ultimately leads to the biological production and cycling of organic carbon and related elements. It also is clear that an integrated knowledge of biological, chemical, and physical factors is required to understand biogeochemical dynamics within the cold desert ecosystem of the McMurdo Dry Valleys. While various aspects of this ecosystem have formed the basis of several excellent publications, the compendium of manuscripts published within this volume represents a first attempt to compile complementary information on the abiotic and biotic components of the McMurdo Dry Valleys and link them in a final synthesis chapter.