
Many factors make Antarctic ecosystems ideal for biological research.
Their simplicity, for instance. Conditions are so harsh that few
life forms survive above the ice. A simple, land-based ecosystem
is easier to study. There are fewer variables to consider, so conclusions
are easier to draw.The dry valley region, just a few miles from
McMurdo, has an extremely basic ecosystem.
The Dry
Valley Ecosystem
|
All aspects of the Dry Valleys are studied,
from the seasonal flow of glacial streams to microscopic worms,
called nematodes, that live in the gravelly, dry soil.
Researchers can focus on specific aspects
of an ecosystem - microscopic animals or geologic processes
- in relative isolation.
As scientists begin to understand how
these basic ecosystems work, they can apply this knowledge
to systems that are more complex.
|
Under the ice, though,
ocean life is rich, complex, and abundant. The
Southern Ocean with its pack ice zone is a most unusual and highly
specialized habitat, with ecosystems of great intrinsic scientific
interest and resources of commercial value, such as krill, squid
and fish. Past exploitation of these resources, particularly the
baleen whales, has caused perturbations that provide a unique large-scale
experiment.
Virtually all life native to Antarctica
is supported by the food-rich sea surrounding the continent.
All are dependent upon each other as
parts of a continuing food chain, beginning with phytoplankton
(algae, particularly diatoms) and zooplankton (including krill)
and extending through the fishes, squid, octopus, sea
birds (including
penguins), and the large marine mammals (whales,
porpoises, and seals).
|
In addition, the Antarctic
region has relatively young terrestrial and inland water ecosystems,
in which single species are often very abundant. These systems offer
scientists a wealth of information about species adaptation and
reproduction. What's more, the coastal region is ideal for the study
of dispersal and colonization across great expanses of ice and ocean.
The unusual environmental
conditions found on Antarctica, such as extreme cold and extreme
seasonal and daily light cycles, offer unique opportunities for
the study of evolutionary processes.
Biologists are interested
in how these features affect adaptation and survival strategies
in a wide variety of organisms not only within single generations
but also over thousands of years.
Finally,
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. Therefore any biological research must take
into account the effects of climate
change, specifically global warming, on species' long term prospects.
Life in
the Interior
|
- Except for a few tiny insects, algae,
lichens, mosses, and microscopic life forms, the Antarctic
interior is too barren and has too harsh an environment
to support significant plant and animal life.
- The climate is too cold, dry, and windy,
and the winter nights too long to encourage any but the
most hardy organic growth.
|
|