Before I slipped away for vacation last week, I was able to write this (sub. req.):
New Mexico's massive piñon die-off of 2002 and 2003 might be a harbinger of life here in a warming world, new research suggests.High elevation forests that had survived previous droughts saw as much as 90 percent piñon mortality, a team of researchers led by University of Arizona ecologist Dave Breshears reported Monday in the Proceedings of the National Academy of Sciences.
"Across a whole landscape, this system got whacked," Breshears said in a telephone interview.
Drought weakened the trees enough that bark beetles could kill them, but warmer temperatures appear to have played a key role, the scientists found.
The temperature difference— 1 to 2 degrees Fahrenheit above the long-term average— might not sound like much. But the scientists say it made the difference, leading to tree death in areas relatively unaffected by the drier drought of the 1950s.
"This is a different kind of response than we saw following the 1950s drought," said Breshears, who has been studying piñon woodlands since the 1980s. "This drought was hotter."
Breshears, in an interview, was careful not to blame the 2002 die-off on human-caused global warming, saying no one event can be unequivocally linked to the planet's long-term rising temperature trend.
But he said the dramatic drought-induced changes in the Southwest's landscape since the turn of the 21st century are consistent with global climate change projections.
"We're more likely to get more frequent, more intense droughts," Breshears said.