"For centuries, the mountain peaks in and around Yellowstone National Park were a healthy, frigid environment for the whitebark pine tree.

But as global warming snakes its way into higher altitudes, a less-welcome resident in taking up space in this fragile ecosystem: the mountain pine beetle.

The last few decades have seen warmer temperatures and forests ravaged by the beetle, the reach of which effects wildlife from woodpeckers who live in the whitebark pine to grizzly bears that eat its cones."

Elizabeth Shogren reports for NPR December 26, 2010. [2]