Bark Beetles, Wildfires, and Global Warming

My NRDC colleagues and I have written a lot about the tragic demise of whitebark pine trees in the Northern Rockies, primarily caused by mountain pine beetles, which are thriving with a warming climate, and the catastrophic effects the loss of whitebark pine seeds will have on Greater Yellowstone Ecosystem grizzly bears, who rely heavily on whitebark pine seeds as a food source.  (As we like to say, bears in Alaska have salmon, bears in Glacier have berries, and bears in the GYE have whitebark pine seeds.)

On this subject, published this past weekend was an interesting (and severely depressing) Associated Press article about the twin plagues of beetles and fire, which are ravaging the forests of the western United States and Canada.  Scientists say such devastation, because of climate change, is a preview of the future.

The article describes the destructive paths of both the spruce beetle in the boreal forests of Canada and the mountain pine beetle in the Rockies -- both of which, thanks to warming temperatures, are wreaking havoc on coniferous forests and leaving millions of acres of dead trees in their wake. 

Also discussed is scientists' concern that mountain pine beetles will spread farther north outside their native range (again, thanks to warming temps and fewer deep freezes in the winter) and attack the Yukon's pine trees, which did not co-evolve with the beetles and likely have no natural defenses. 

That worst-case scenario is already unfolding with whitebark pines in the GYE.  Because whitebark pines inhabit the high country of the Rockies, where the winters are harsher, they did not co-evolve with the beetles, as prolonged winter cold snaps generally prevented the beetles from flourishing in whitebark country.  Warming temperatures are enabling beetles to survive at ever higher elevations.  As a result, whitebark pines, without natural defenses developed over time, are being slaughtered by beetles across the Northern Rockies. 

(On the contrary, lodgepole pine in the Rockies, a lower-elevation tree, are also being hit hard by mountain pine beetles, but lodgepole and the beetles co-evolved, so lodgepole have some natural physical and chemical defenses.  Such beetle-kill outbreaks are more of a natural occurrence for them.)

And the preliminary reports from the Whitebark Pine Aerial Assessment Team, who have finished flying the GYE and are currently compiling and digesting a staggering amount of data, are bad -- really bad -- with the Team finding that a massive amount of whitebark pines in the GYE are dead or dying. 

The ever-worsening cycle of warming temperatures, beetle kills, dead trees, fires, more greenhouses gases, warming temperatures, beetle kills . . . is frightening -- and another reason the Senate must pass meaningful climate legislation this fall.

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