Sometime last year, I wrote a couple posts about wildfire and/or bark beetles and forest health, so it was really cool to find another article recently explaining how the “devastation” brought by the beetles may actually help prevent more extreme fires in the future. From “Insect outbreaks help forests survive wildfires” (which mentions the spruce budworm, a moth, as well as bark beetles):
…conventional knowledge holds that insect outbreaks increase the risk of and damage from wildfires. The logic is that these insects increase the amount of fuel for a fire because they kill so many trees. The 2014 US Farm Bill even designated $200 million each year for wildfire prevention measures across 18 million hectares (100 hectares = 1 square kilometer) based upon this assumption. There’s just one problem: that assumption may not rest upon a foundation of solid science.
“Recent studies indicate that insect outbreaks generally do not increase wildfire likelihood, [and] key uncertainties remain regarding the influence of insect outbreaks on subsequent wildfire severity,” writes Garrett W. Meigs of Oregon State University’s College of Forestry.
By comparing wildfire activity with insect outbreaks, the team found evidence that directly contradicted the prevailing wisdom. Rather than exacerbating wildfires, insect outbreaks might actually reduce their damage.
What’s not yet clear is how insect outbreaks reduce the severity of wildfires, but the researchers have at least one guess. In killing or defoliating the trees, the insects are moving the fuel along both horizontal and vertical gradients, both by thinning the forests and by moving biomass from the canopies to the ground. This movement may alter forest connectivity enough that fires could have a harder time spreading.
I’d like to think that the various governmental agencies that have an impact on logging practices, especially those done with the claim that they will reduce forest fires, will take these facts into stronger consideration than the pressures they undoubtedly get to keep logging (or “thinning,” or whatever cover-up phrase they use to make it sound like a good idea).