Canadian scientists say much of their nation's northern tundra is rapidly disappearing, being replaced by trees and shrubs, forcing wildlife from the region.
A University of Alberta study shows the climate shift is occurring at a rate much faster than scientists had predicted, adding to a growing body of evidence concerning effects of global climate change.
The boundary, or tree line, between forest and tundra ecosystems is a prominent landscape feature in both Arctic and mountain environments. As global temperatures continue to increase, the tree line is expected to advance, but the new research shows the shift will not always be a gradual one.
"The conventional thinking on tree line dynamics has been that advances are very slow," said Ryan Danby, of the university's department of biological sciences. "But what our data indicate is that there was an upslope surge of trees in response to warmer temperatures. It's like it waited until conditions were just right and then it decided to get up and run, not just walk."
The research by Danby and David Hik, also from the school's faculty of science, is detailed in the Journal of Ecology.
Copyright 2007 by United Press International
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