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McMurdo Dry Valleys, Long-Term Ecological Research Network Office

Service Provider Description
The McMurdo Dry Valleys LTER project is an interdisciplinary study of
the aquatic and terrestrial ecosystems in a cold desert region of
Antarctica. In 1992 this area was selected as a study site within the
National Science Foundation's Long-term Ecological Research (LTER)
Program. Details about the research can be reviewed through the
original 1992 research proposal to the National Science Foundation, or
the more recent 1998 proposal, resulting in funding for another 6
years. The McMurdo LTER project is one of 21 sites comprising the LTER
Network and is conducting long-term ecological research in a broad
array of ecosystems. Each site within the LTER Network shares a common
commitment to create a legacy of well-designed and well-documented
long-term field experiments and observations for use by future
generations to improve understanding of basic properties of ecosystems
as well as factors causing widespread changes in the world's
ecosystem. Sites are also required to synthesize research efforts,
such as response to natural and anthropogenic disturbances, and to
extrapolate from local scales to continental and global scales.

The McMurdo Dry Valleys are located on the western coast of McMurdo
Sound (77?00'S 162?52'E) and form the largest relatively ice-free area
(approximately 4800 square kilometers) on the Antarctic
continent. These ice-free areas of Antarctica display a sharp contrast
to most other ecosystems in the world, which exist under far more
moderate environmental conditions. The perennially ice-covered lakes,
ephemeral streams and extensive areas of exposed soil within the
McMurdo Dry Valleys are subject to low temperatures, limited
precipitation and salt accumulation. Thus, the dry valleys represent a
region where life approaches its environmental limits, and is an
"end-member" in the spectrum of environments included in the LTER
Network. The dry valleys, unlike most other ecosystems, are dominated
by microorganisms, mosses, lichens, and relatively few groups of
invertebrates; higher forms of life are virtually non-existent. The
overall objectives of the McMurdo LTER are to understand the influence
of physical and biological constraints on the structure and function
of dry valley ecosystems and to understand the modifying effects of
material transport on these ecosystems. The McMurdo Dry Valley
ecosystems are driven by the same basic processes, such as microbial
utilization and re-mineralization of nutrients found in all
ecosystems, but they lack many confounding variables, such as higher
plants and animals, found in other ecosystems. McMurdo LTER research
contributes to general ecological understanding through studies of
processes that are readily resolved in these ecosystems. To
successfully accomplish these studies, scientists must be present in
the field--the McMurdo Dry Valleys. Samples and measurements cannot be
obtained remotely and experiments must be conducted in situ if they
are to have any relevance to the environment.

Why is it necessary to conduct long-term ecological research on the
McMurdo Dry Valleys of Antarctica? To summarize from the McMurdo LTER
Site Review Committee's January 1997 report, "the McMurdo LTER project
is working on an incredible system for ecological study. It is not
just a unique area, but more importantly, it exists at one end of the
arid and cold spectra of terrestrial ecosystems." All ecosystems are
dependent upon liquid water and shaped to varying degrees by climate
and material transport, but nowhere is this more apparent than in the
McMurdo Dry Valleys. In very few places on this planet are there
environments where minor changes in climate so dramatically affect the
capabilities of organisms to grow and reproduce. Indeed, the data
being collected by the LTER indicate that the dry valleys are very
sensitive to small variations in solar radiation and temperature and
that this site may well be an important natural regional-scale
laboratory for studying responses to human alterations of
climate. While the Antarctic ice sheets respond to climate change on
the order of thousands of years, the glaciers, streams and ice-covered
lakes in the McMurdo Dry Valleys respond to change almost
immediately. Thus, it is in the McMurdo Dry Valleys that the first
effects of climate change in Antarctica should be observed.


[Summary provided by McMurdo Dry Valleys LTER.]
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