Perilous Times and Climate Change
Climate change killing off Alaskan spruce forests
by Staff Writers
Fairbanks, Alaska (UPI) Aug 25, 2010
Alaskan forests of white spruce and other trees are suffering from the
effects of climate change and rises in temperature, researchers say.
Experts say stands of white spruce, which a recent study found contain
half of the genetic diversity of all white spruce in North America, are
suffering, ScientificAmerican.com reported Wednesday.
"A biome shift is now occurring," University of Alaska, Fairbanks,
forest ecologist Glenn Juday said. "You don't have to wait for the
effects. They're happening."
North America's white spruce require at least 11 inches of rain each
year, a number that rises if mean summer temperatures are higher than
around 60 degrees F.
When temperatures hit a mean of just below 70 degrees F, the trees
can't survive.
In Fairbanks, conditions are hovering right on that edge. July
temperatures have exceeded 70 F several times in the last 20 years,
Juday said.
As a result, white spruce growing around Fairbanks are "probably not
viable on a long-term basis under such conditions," Juday said. "With
each additional degree of warming, their growth goes down."