USA — Not enough is known about the mountain pine beetle infestation of Colorados forests, and similar infestations in other forests around the world, to say for sure whether the phenomenon will contribute heavily to global warming in the coming decades.
Thats according to scientists, government bureaucrats, community activists and elected officials who gathered this week at The Aspen Institute to discuss a broad array of topics relating to the beetles. A local organization, For The Forest, convened the meeting.
In fact, experts cannot entirely agree on exactly how much of Colorados lodgepole pine forest will be decimated by the ravenous beetles.
The infestation already has killed huge numbers of trees over much of the western United States, including Summit and Grand counties in Colorado, and is now threatening the hillsides and mountaintops around Aspen and the Roaring Fork Valley. But according to one expert, Jeff Hicke of the University of Idaho, current research suggests that even in areas hardest hit by the beetles, not all the trees will die. And as the forest regenerates, several scientists argued, the trees will be able to undo any damage done to the atmosphere by their dying off in the first place.
Colorados forests have been under siege by the mountain pine bark beetle, also known as the mountain pine beetle, for several years.
The current wave of infestations of Rocky Mountain forests began in Canada, where it has killed off as much as 50,000 square miles of forest, and is rapidly spreading south. Some experts believe the infestation eventually will get as far as Florida. The beetles attack primarily lodgepole and ponderosa pines, but they have been known to jump to other species when neither of their favorites is available.
Thursdays meeting in Aspen began with remarks by a dozen of the attendees, who described different aspects of the beetle problem, as well as other factors contributing to global warming, as viewed from their respective specialties.
Dr. Mike Ryan, a forest ecologist from the U.S. Forest Service, said a critical aspect of the infestation is that the trees, once dead, no longer absorb carbon dioxide (C02).
The C02 absorbed throughout a trees life, he explained, is considered to be stored in the tree. As millions of trees die, according to Ryan and others, that carbon can be released either through fire or decomposition and adds to the greenhouse gas effect that is causing the earths average ambient temperature to rise.
Beetle depredations are particularly a problem if the affected forest fails to regenerate as a forest, and instead becomes a meadow, which is far less carbon-absorbent, Ryan said.
A Canadian study released earlier this year maintained that, in killing off huge swaths of forest, the infestation is on pace to release 270 megatons of C02 into the atmosphere by 2020.
That is the same amount of greenhouse gas emissions that Canada is committed to reducing by 2012 under the Kyoto Protocol, and would effectively doom that effort to failure, the study says, according to an article in a Canadian environmental journal, TerraDaily.
Some commentators have suggested that, as the trees die and release carbon dioxide into the atmosphere, that will in turn trigger further trouble for the worlds forests, including disease and insect infestations, in a compounding effect that will in turn worsen global warming.
But Dr. Jeff Hicke of the University of Idaho, among others, said there is not enough evidence to support that argument.
Its highly likely that the forest will come back … in probably less than 50 years, said Ryan, adding that in that case the evidence indicates that the forest, once regenerated, will be able to reabsorb all the carbon it lost through the beetle kill.
The beetle symposium continues Friday with discussion of a recent stand survey of the forest in Hunter Creek and Smuggler Mountain, options for coming up with money to deal with the beetle problem, and a look at what strategies exist to combat the bug. Former Aspen Mayor John Bennett, head of For The Forest, noted that the topic at hand is a small problem at the moment for the Roaring Fork drainage, but it has potential to pose a serious threat, if only for the forest fire hazards represented by the dying trees.
Other topics discussed during Thursdays meeting included a talk by Dr. Jessica Clement of Leadville about what a community can do to prevent being destroyed by a catastrophic forest fire; and ideas from research entomologist Nancy Gillette and Dr. Ingrid Aguayo of the Colorado State Forest Service on what landowners can do to treat trees threatened by the mountain pine beetle.