Global Warming Hurting Trees & Grizzly Bears in Yellowstone

"Whitebark pine is a rugged, tough, resilient, beautiful tree that inhabits the high country of the Northern Rockies. Whitebark pine is typically the last tree one sees before going above timberline. Whitebark pine seeds - or pine nuts - feed Clark's nutcrackers, red squirrels, and grizzly bears.

"In the Greater Yellowstone Ecosystem (GYE), whitebark pine seeds are the primary food source for grizzly bears during late summer and fall when the bears are trying to fatten up for their winter hibernation. Bears in Alaska have salmon, bears in Glacier National Park have berries, and bears in the GYE have whitebark pine seeds.

"But the whitebark pine population is being rapidly decimated by global warming.

"The main killer is the mountain pine beetles mountain pine beetle, which bores through the tree's bark, cuts off its supply of water and nutrients, and starves it to death. A second killer is blister rust, a fungus accidentally introduced from Europe in the late 1800s.

"While mountain pine beetle are native to the West, the high-altitude environment that whitebark pine trees inhabit has typically been too cold and harsh for the beetles to do any damage. Prolonged cold snaps (i.e., 40 below zero for several days) in whitebark country previously prevented major beetle infestations.

"But global warming has changed that..."

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