COLUMBUS , Ohio -- Small insects that inhabit some of the most remote parts of the United States are sending a strong message about climate change. New research suggests that changes in midge communities in some of these areas provide additional evidence that the globe is indeed getting warmer.
Researchers created a history of changing midge communities for six remote mountain lakes in the western United States. Midges, which resemble mosquitoes but usually don't bite, can live nearly anywhere in the world where there is fresh water.
The insect remains revealed a dramatic shift in the types of midges inhabiting these lakes in the last three decades, said David Porinchu, the study's lead author and an assistant professor of geography at Ohio State University.
"Climate change has had an overriding influence on the composition of the midge communities within these lakes," he said. "The data suggest that the rate of warming seen in the last two decades is greater than any other time in the previous century."
The data suggest that, starting around 25 years ago, warmer-water midges began to edge out cooler-water midge species around these remote lakes.
"People would like to believe that these mountainous environments may be immune to climate change, but these are some of the first areas to feel the impact of warmer temperatures," Porinchu said.
He and his colleagues presented their findings December 15 in San Francisco at the annual meeting of the American Geophysical Union.
The researchers gathered sediment from six small lakes in the Great Basin of the western United States a vast watershed bounded roughly by the Sierra Nevada and Rocky Mountain ranges. Since the lakes are accessible only by foot trail, the researchers carried in an inflatable raft during the summer months in order to collect sediment samples from the middle of the lakes. The lakes range from 8.2 feet (2.5 meters) to 34.5 feet (10
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Contact: David Porinchu
Porinchu.1@osu.edu
614-247-2614
Ohio State University
11-Dec-2006