Wednesday, July 14, 2010

Tropical butterflies join polar bear on climate threat list

Liz Kalaugher in Environmental Research Web: Species in tropical regions could suffer as much impact from climate change as those at higher latitudes. That's according to scientists at Stanford University, US, who looked at how well animals and plants have evolved to cope with variations in temperature and rainfall.

"Polar bears have become an icon for species threatened by climate change, and justifiably so; at the high latitudes of their home, climate-change projections show very large changes in temperature relative to lower latitudes," Tim Bonebrake of Stanford University, US, told environmentalresearchweb. "Our study demonstrates how incorporating other critical variables (e.g. precipitation and adaptation to climatic variability) indicates that polar bears may not be the only species threatened by climate change; lower latitude and tropical species could face equally significant challenges under future climatic regimes."

…"We applied the adaptive evolutionary model to global climate data to quantify the effects of variability in both temperature and precipitation for species throughout tropical and temperate ecosystems," said Bonebrake. "In other words, if a species is adapted to seasons of wet and dry vs. hot and cold, how will that affect its ability to respond to climatic changes?"

The results indicated that warming caused the greatest change in fitness at the tropics because of tropical organisms' reduced ability to cope with a broad range of temperatures. Precipitation changes tended to have the most impact in high-latitude northern regions and the smallest effect in high-latitude southern regions. Northern high latitudes experience relatively constant precipitation year-round while climate change is projected to bring large effects on rain and snowfall....

Detail of a Ulysses butterfly wing. Taken in the Melbourne Zoo, November 2006, shot by Fir0002,, Wikimedia Commons, under the terms of the GNU Free Documentation License, Version 1.2 only as published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.

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