Understanding the mountain pine beetle: Seven facts you need to know

June 17, 2009 By Greg Aplet, Ph.D.

Beetle kill in Rocky Mountain National Park, Colorado

Credit: Tim Wilson, Courtesy Flickr

I’m looking out my window right now and savoring a magnificent view of the Rockies — it’s just one of the perks of living in Colorado. Recently, though, many Coloradoans have been seeing the familiar hilltops and mountainsides turn from green to red, as the mountain pine beetle continues its spread throughout the West.

As more people become aware of the challenges raised by the pine beetle outbreak it is vital that citizens and policymakers understand the ecology behind the outbreak.

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- Related CBS news story

That’s what I shared with reporters in a recent teleconference we conducted in advance of a U.S. House of Representatives hearing June 16. I reiterated the scientific consensus on the nature of the lodgepole pine ecosystem with respect to beetles and fire.

This consensus can be summarized in seven points.

1. The scale and intensity of the ongoing mountain pine beetle epidemic is unlike any outbreak that has been observed before, but that does not mean the end of lodgepole pine in the Rockies.
2. These forests have undergone dramatic change in the past, and they are resilient to mountain pine beetle and other disturbances.
3. Even in the existing forest, variability in age, density, and species composition ensures that there will be different responses to the beetle outbreak in different places.
4. Once an outbreak gets going, there are no known treatments that can influence its spread.
5. Infrequent, large fires are the norm in lodgepole pine forests, and they are likely to be in the future — with or without beetles. There is general agreement that as the dead needles fall from the trees, the probability of crown fire will diminish, but the probability of surface fire may increase.
6. Because mountain pine beetle outbreaks do not disturb the soil, they are not likely to cause increased erosion, though they may increase water yield.
7. Changes like we are observing in the current mountain pine beetle outbreak are not unlike the changes we should expect from climate change in the decades ahead.

Although the three of us on the panel combined probably only spoke for about 10 minutes, the dozen or so journalists kept us on the line for 45 more, bringing up one insightful question after another. I hope that Congress will be as interested and attentive in the science behind the bark beetle at their hearing on Tuesday as these reporters were during our conference. After all, it is only with a clear understanding of the scientific and ecological factors shaping the beetle outbreak that we can craft smart policies at local, state, and federal levels.

Editor's Note: Greg Aplet appeared in a CBS news segment explaining that forests that have been attacked by bark beetles will eventually bounce back with more diversity in the ages and species of trees. Watch the clip:

photo: Beetle kill in Rocky Mountain National Park, Colorado. Photo by Tim Wilson, Courtesy Flickr.