Juday and co-authors at Woods Hole Research Center in Massachusetts and the University of Paris compared growth rings from trees across boreal Alaska with satellite-based estimates of forest productivity. Their study was published in the April edition of the journal Ecology Letters.
They concluded a biome shift is already underway in Alaska as higher temperatures limit forest productivity in Interior Alaska. Meanwhile in Western Alaska, where temperatures previously had been marginal for tree survival, tree growth is up, they found.
The pattern, Juday said, is "one of the first conclusively demonstrated examples of a biome shift" in response to climate change.
"It's just collapsing where it exists now and a new place exists where it can thrive," added.
The problem, he cautioned, is that the new region is much smaller than the old.
DailyClimate.org is a nonprofit news service covering climate change.
On the web:
Study of Russian boreal forest in Global Change Biology:
Study of Alaska's boreal forest in Ecology Letters:
Pew Environment Group Boreal Conservation Campaign:
TDC story on Canada's efforts to save the boreal (July 19, 2010)