Bark Beetle Outbreaks Will Spread as Forests Adapt to Climate Change

Mountain pine bark beetle infestation has brought devastation throughout the forests of the American West in recent years. In the face of a changing climate, especially in the high mountain forests of the Sierra, Rocky, and Cascade mountain ranges, the pine beetle has killed large swaths of Whitebark Pine as warmer winters allow the beetle to survive and multiply, leaving the trees virtually defenseless to attack and affecting entire ecosystems.

According to recent reports, Colorado and Wyoming have lost 3.5 million acres of mountain forest to the bark beetle, with up to 100,000 trees on average falling every day, prompting the U.S. Forest Service to take aggressive action to clear out thousands of dead trees in an effort to keep roads and trails clear.

As bad as the problem is, it looks to get even worse, says a new study by scientists with the U.S. Forest Service. Published in the September issue of the journal BioScience, the report cautions that outbreaks of spruce and and mountain pine beetles will rise significantly in coming decades, as coniferous forest from Mexico to Alaska adjust to climate change.

Global Warming is a “Good Thing”

Especially for bark beetles.

Bark beetles are “influenced directly by shifts in temperature,” says Chris Fettig, a research entomologist and a co-author of the study.

“…climatic changes on the order of what is expected would increase the population success of both spruce beetle and mountain pine beetle throughout much of their range,” he added.

The Forest Service hopes that this latest research will assist with ongoing efforts to sustainably manage forests and respond to the effects of changing climate by providing a clear assessment of the trajectory forest ecosystems are headed.

The research comes as Congress grapples with legislation intended to deal with the impact of bark beetle outbreaks in western North America. The Forest Ecosystem Recovery and Protection Act was introduced in the House last spring Wyoming Representative Cynthia Lummis. Govtracks summarizes the bill:

To require the Secretary of Agriculture to designate national forests or portions of national forests in western States as locations for demonstration projects to prevent or mitigate the effect of pine beetle infestations and conduct forest restoration activities, to authorize the emergency removal of dead and dying trees to address public safety risks in western States, to make permanent the stewards hip contracting authorities available to the Forest Service, and for other purposes.

The bill sits in Congress (where, it seems of late, little gets done), and faces opposition from the Obama administration, saying the legislation is “flawed.”

Ray Jensen, the Department of Agriculture undersecretary for Natural Resources and Environment, has said  the Administration “does not believe the bill is the best approach.” Jensen cites as untenable the bill’s requirement for the Agriculture Department to set up projects demonstrating ways to prevent bark beetle outbreaks since there are no known measures to stop the bark beetle.

He has also complained about provisions in the bill exempting private utilities with rights-of-way through national forests from the cost of repairing damage from felled trees in areas affected by bark beetle infestations. Jensen expresses concerns that taxpayers will thus be saddled with the costs related to how effectively a private utility manages land for which they are responsible.

Lummis counters that Jensen “misunderstands or mischaracterizes”  the bill.

But the bark beetle does not wait for Congress. Some studies indicate that more the 17.5 million acres of forest in the west are now infected. Whatever solutions may be found to curb the destruction of forests in western North America, it is clear that climate change is rapidly altering mountain and forest ecosystems.

Image credit: Al_HikesAZ, courtesy Flickr

Thomas Schueneman
Thomas Schueneman
Tom is the founder and managing editor of and the PlanetWatch Group. His work appears in Triple Pundit, Slate, Cleantechnia, Planetsave, Earth911, and several other sustainability-focused publications. Tom is a member of the Society of Environmental Journalists.

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