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Research Objectives:
Much of what is known about such extreme polar deserts has been discovered by work conducted in Antarctica because few comparable systems exist elsewhere. Much of our knowledge about the structure and function of these polar desert ecosystems has been discovered only recently resulting, in large part, from the first phase of the McMurdo Long-Term Ecological Research program (MCM-I) from 1993 to 99. In MCM-I, researchers explored the physical constraints controlling the structure and function of this polar desert. They discovered that subtle changes in temperature, precipitation, and albedo have profound effects on the hydrologic cycle, biogeochemistry, productivity and biodiversity within the valleys. Moreover, local effects are modified by landscape position and topography.
The Dry Valleys ecosystem is sensitive to very small variations in climate because the change between solid and liquid phase of water is delicately poised in this environment. Thus, small changes in temperature and radiant energy regimes are amplified by large, non-linear changes in hydrologic budgets that can ramify throughout the system. The presence of liquid water remains the primary limiting condition for life in Antarctica, so the relationship of energy balance to liquid water availability, ecological function and biological diversity will continue to be a major emphasis of the McMurdo Dry Valley LTER program.
This project is the lake pelagic and benthic productivity and microbial food webs component of McMurdo LTER. The group will continue measurements of biological, chemical, and physical limnological properties of Dry Valley lakes, with special emphasis on LTER core research areas. They will also measure other parameters relevant to modeling the Taylor Valley Lake Ecosystems.
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