Already Wall's team has observed the impact of an 8-year-long cooling trend in the Dry Valleys. To the scientists' surprise, populations of all three nematode species have decreased.
"These worms are tough, and we thought they would thrive if it got colder," Wall says.
All three species of nematode survive the nine-month winter by dehydrating themselves and triggering a state of suspended animation called anhydrobiosis. With summer and rising moisture the worms wriggle back to life.
"Just add water and these things start kicking again," says Adams.
Greenhouse Effects in the "Worm Farms"
The researchers suspect that the cooler temperatures do not provide enough opportunities to reanimate and reproduce. If the cooling trends continue, all the species of worm could be susceptible to extinction, says Adams.
In their "freeze-dried" state the nematodes may literally blow away. Some of these windblown nematodes may land in wetter, more hospitable soil near lakes and streams—and survive the colder temperatures.
To help determine how temperature and other factors affect the worms of the Taylor Valley, Wall has set up more than 100 open cones, or "chambers," housing different experiments in areas dubbed "worm farms." Some 32 chambers have operated since 1993. Each cone creates a greenhouse effect, raising the temperature of the soil about 1 to 2 degrees Fahrenheit (2 degrees Celsius).
So far the warmer temperatures in the cones have also led to a decline in nematode populations.
"The heat dries the soil, acting like a wick and pulling up all the moisture," says Wall.
Warmer global temperatures could threaten nematodes and other microscopic players in the soil food web—ultimately changing the chemistry and nutrient content of the soil, according to Wall. "So far, though, our results are inconclusive," she says.
During the next 50 to 100 years, global surface temperatures will rise by an average of about 5 degrees Fahrenheit (3 degrees Celsius), according to the International Panel on Climate Change, established by the World Meteorological Organization and the United Nations Environment Program.
The most important players in the future of climate are much more sophisticated creatures than the Antarctic worms.
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