Scientists: Warming may greatest threat to tropical species
AP
Posted: 2008-05-05 17:16:00
WA****NGTON (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 relation****p 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 Wa****ngton 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."
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05/05/08 17:05 EDT
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