The researchers spoke Friday at a conference in Aspen.
Jim Worrall, a U.S. Forest Service plant pathologist, says overwhelming circumstantial evidence indicates climate change has left aspens stressed and vulnerable. About 845 square miles of aspens died in 2008.
The Aspen Times reports Worrall predicted that by 2060, aspens will lose more than 68 percent of their current habitat because of changing conditions.
University of Montana professor Diana Six says white pines, which dominate forests in Montana and parts of Wyoming, have begun to fall victim to bark beetles because warmer temperatures have allowed the bugs to move north.
(Copyright 2011 by The Associated Press. All Rights Reserved.)