WASHINGTON (AP) - While global warming is expected to be strongest at the
poles, it may be an even greater threat to species living in the tropics,
scientists say.
Tropical species are accustomed to living in a small temperature range and
thus may be unable to cope with changes of even a few degrees, according to an
analysis in Tuesday's edition of Proceedings of the National Academy of
Sciences.
"There's a strong relationship between your physiology and the climate you
live in. In the tropics many species appear to be living at or near their
thermal optimum, a temperature that lets them thrive. But once temperature gets
above the thermal optimum, fitness levels most likely decline quickly and there
may not be much they can do about it," Joshua J. Tewksbury said in a statement.
The research was led by Tewksbury, an assistant professor of biology at the
University of Washington, and Curtis A. Deutsch, an assistant professor of
atmospheric and oceanic sciences at the University of California, Los Angeles.
Concern over global warming has largely focused on arctic species like the
polar bear. But such animals may be accustomed to living in a wide range of
temperatures, while there tends to be little change in the tropics, so there has
been no need for species there to adapt.
"The direct effects of climate change on the organisms we studied appear to
depend a lot more on the organisms' flexibility than on the amount of warming
predicted for where they live," Tewksbury said. "The tropical species in our
data were mostly thermal specialists, meaning that their current climate is
nearly ideal and any temperature increases will spell trouble for them."
Copyright 2008 Associated Press. All rights reserved. This material may not be
published, broadcast, rewritten, or redistributed.
|