New research could help inform forest management
By Bob Berwyn
SUMMIT COUNTY — While many forest managers and politicians are still broad-brushing the wildfire danger associated with beetle-killed forests, a new report once again suggests that the fire hazard linked with beetle-kill has been overstated.
After reviewing some of the latest research, the authors of the paper concluded that, “To date, the majority of studies have found no increase in fire occurrence, extent, or severity following outbreaks of spruce beetle … and mountain pine beetle … in Colorado, Wyoming, and other areas.”
Instead, there’s more and more evidence that climate — specifically global warming — is the main factor.
“The main message is that, if we want to understand fire dynamics, we need to understand the ultimate cause and effect,” said CSU professor Barry Noon, one of the coauthors. “The real drivers are drought conditions, temperatures and precipitation. That highlights the human factor in the equation,” Noon said, referring to global warming driven by greenhouse gas emissions. “That may make us uncomfortable, but the evidence just keeps accumulating all the time,” he said.
“The studies pretty clearly show that fires and bark beetles linked to the same thing; drought, warming and climate change,” said coauthor Scott Black, of the Xerces Society for Invertebrate Conservation.
“We’ve looked at studies from fire experts, geographers … there is no evidence to show that there are more fires when the trees are dead,” Black said. “It’s really all about the climate. If you have drought, the trees are stressed and you have larger bark beetle outbreaks.”
The paper is partly framed in the context of the persistent pressure “to do something” about bark beetle outbreaks, as land managers and politicians push for more funding to do landscape-level mechanical treatments.
Nobody disputes the need to try and reduce potential wildfire damage right around homes and other developments, but there is still a debate about whether large-scale treatments could help reduce the chance for catastrophic crown fires.
But the BioOne paper concludes that active crown fires happen when forests are dry, and not by variations in stand structure.like those resulting from beetle infestations. Thinning may help prevent small outbreaks, but probably won’t reduce susceptibility to large, landscape-scale epidemics.
There just aren’t any studies out there showing that there are more wildfires in beetle-killed forests, Black said.
“I think what’s important about this is, I really understand how you get this visceral reaction when the trees turn brown. That’s been the situation the past decade. We want to take action, but that action is not as easy or as clear as one might think. Because climate is driving bark beetle and fires, logging may not get us anywhere.”