Global Signal Roundworms

How fast are humans changing the global environment? Environmental Studies Chair Ross Virginia thinks an answer is in the dirt. For the past three years he has been measuring the environment where it is at its harshest: the Dry Valleys of Antarctica, a climate so tough that organisms grow better inside rocks and underground than anywhere else on the continent. Virginia studies nematodes, simple microscopic round-worms found in soils all over the world.

Though nematodes are extremely simple animals, they are closely linked with the complex chemistry of the soils they inhabit. Checking up on nematodes is a quick way of studying more complex changes in the soil, which are caused by larger issues like global warming. Virginia plans to use nematodes in the Antarctic as a sort of canary in the coal mine, a potential indicator species of global environmental quality. The average rainfall in most of the dry valleys is comparable to the Sahara Desert; what little water there is, is usually frozen. The ice-free rocks can heat up above the ambient temperature and support life within their pores.

Nematodes are the most complex life form that can survive the extreme cold and drought found in these peculiar ice-free areas. During a short window of time around Christmas, the weather is warm enough to melt the sparse snow and heat the Antarctic soils enough for the nematodes to come out of their dormant state. In his research in other warmer and more complex deserts, Virginia said it was difficult to isolate the effects of plants and humans on the soil, and to distinguish plant and animal effects from those of nematodes. In the Dry Valleys of Antarctica, there are no higher plants or animals to disturb the soils.

The National Science Foundation has funded a six-year Long Term Ecological Research project for the Dry Valley areas, which includes Virginia's project. He expects the ecological research will continue even longer than that. "We're there for three or four weeks [during the austral summer] and then we're gone," he said, "It's going to take a lot of persistence to really understand how these systems are put together."

Ross Virginia encounters curious penguinswhile sampling soil ina Cape Byrd rookery.Right, magnified viewof a nematode.