Local forest officials say they are not surprised by a recent study downplaying the impact spruce beetle infestation has on severe wildfires.
Researchers at the University of Colorado Boulder last month published findings that infestations may not be to blame for increased severity of wildfires. The study was published in the journal Ecological Applications.
Researchers examined five subalpine fire zones in the San Juan Mountains of Southwest Colorado. Factors such as topography and weather conditions play a larger role than beetle kill in determining the severity of Colorado’s subalpine wildfires, according to the study.
Lary Floyd, assistant fire management officer for the U.S. Forest Service’s Rio Grande National Forest, said the study lines up with his office’s own observations of the forest.
“The report ... was not shocking and it actually kind of supported, in a different way, some thoughts that a couple of us here locally had come to,” Floyd said. “We’re not saying that the bugs aren’t affecting fire behavior, but perhaps not to the degree that many would propose.”
There have been reports of beetle kill above Vallecito Reservoir, on the west side of La Plata County near Mancos and in the Shenandoah region.
While the forests of La Plata County likely won’t experience the same devastation as the mountains around Wolf Creek, it is a forest health issue that experts are closely watching.
Beetles have infested more than 1.2 million acres of Engelmann spruce and subalpine fir forests across Colorado. With several large wildfires occurring across the state over the past decade, some fire officials opined that the beetle’s destructive spread may be a contributing factor.
Dr. John Griffiths, a Durango resident and retired firefighter, raised concerns with downplaying the impact beetle infestation has on wildfires.
“I have seen the damage the spruce bark beetle has done,” Griffiths said. “(The report didn’t have) anything to say about the fire hazard that hundreds of thousands of acres of dead trees represent. When those dead trees burn, you will admit, the spruce bark beetle will have had an awful impact on the severity and extent of those fires.”
Forest officials are careful to point out that intensity and severity of wildfires are different. The study focused only on severity.
There’s also not much to infer from the study about the nature of fuels, officials said. Spruce fir forests are always heavily loaded with fuel, whether dead or alive.
“A lot of us approach it as that forest was going to burn with the conditions of the weather, etc.,” Floyd said. “The difference the bugs make would be that instead of an 80,000-acre fire, it would have been a 60,000-acre fire, or instead of 150-foot flames, it had 120-foot flames.”
Kent Grant, district forester for the Durango District of the Colorado State Forest Service, agreed that beetle infestation is only one part.
“CU has a good point, but you have to balance it with what conditions are like at the time,” Grant said.
Forest officials say they are focused on salvaging dead trees for commercial value and also dealing with safety issues, such as dead trees falling down. The timber industry is a way to salvage the dead trees.
“We’re finding out that they can really help us in managing the forest for forest health, which includes insect and disease problems and wildfire concerns,” Grant said. “It’s just another tool in the bag that forest managers can use.”
Floyd said the recent study probably won’t change management practices.
“Once we’ve identified a value that we’re protecting ... we are going to treat that anyway,” he said. “The fact that it’s beetle kill, it might go up in priority a bit ... but in extreme conditions, it wouldn’t matter anyway whether it’s dead or alive.”