Keystone Whitebark Pine Foundering; 95% Of Large Trees In Greater Yellowstone Already Dead
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At a scientific conference Tuesday at Mammoth Hot Springs, near Yellowstone's northern boundary, biologists cited climate change as a major driver. From the 1980s to today, temperatures have only gone one direction: Up. The death is a major concern for conservationists, biologists and public land managers, for the whitebark pine supports the entire ecosystem. Bears, jays and other forest creatures depend heavily on pine seeds for their diet.
Without the seeds, biologists fear what's called a "trophic cascade," where the entire food chain shifts as a primary producer drops out. "The whitebark pine is both a foundation and a keystone species," said Jesse Logan, a retired U.S. Forest Service entomologist. "The health of the whitebark pine is very closely related to the health of the entire ecosystem."
The greater Yellowstone ecosystem, an area the size of South Carolina sprawling for 31,000 square miles across Montana, Wyoming and Idaho, has been hit particularly hard by beetle outbreak. Since 2009, more than 95 percent of the large trees in the region have succumbed to pine beetles.
"We view this as the stage-setting event that has allowed more beetle events," said David Thoma, a National Park Service ecologist studying factors behind the beetle outbreak. "Temperature is the primary driver." Warmer temperatures allow the beetles to overwinter. Until the late 1990s, winter temperatures in the high country were inhospitable. Thirty years' of warming has left whitebark pines exposed to a threat they rarely saw.
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http://www.dailyclimate.org/tdc-newsroom/2014/10/whitebark-pine-yellowstone