Future of forests in U.S. West unclear

CORVALLIS, Ore., Nov. 3 (UPI) -- Climate change and other factors are causing massive movements of tree species across the U.S. West, researchers say.

With global warming, insect attack, diseases and fire, many tree species are projected to decline or die out in regions where they have been present for centuries while others move in and replace them, researchers at Oregon State University said.

Once-common species such as lodgepole pine may be replaced by other trees, perhaps a range expansion of ponderosa pine or Douglas fir, while other areas may see a shift completely out of forest into grass savannah or sagebrush desert, the said.

In central California, researchers concluded more than half of the species now present would not be expected to persist in the climate conditions of the future.

"Some of these changes are already happening, pretty fast and in some huge areas," OSU Richard Waring, lead author of the study, said in a university release Thursday.

"In some cases the mechanism of change is fire or insect attack, in others it's simply drought.

"We can't predict exactly which tree (species) will die or which one will take its place, but we can see the long-term trends and probabilities," Waring said.

"The forests of our future are going to look quite different."