Reply from Cal Wettstein on Bark Beetles and Fire
Cal is retiring fro the Forest Service; currently his is the Acting Deputy Forest Supervisor on the White River, so you might want to send your greetings to him.. Here’s an article about him, when he was bark beetle incident commander (you may have to answer some strange questions to get to the content).
On the BB fire thing, first, I won’t miss the political arguments over it….. but really, I looked at the NASA clip and the naysayers (ie Veblen, Kulakowski, etal) continue to miss the big picture. We’ve been very clear that in pure lodgepole pine, during the red-needle stage ignition is easier and we can get flashy crown fires, but they only last one burn period—there’re no heavy fuels to carry fire for very long. The BB fire connection is several decades out. The dead trees fall over 15-20 years (hopefully they’re not disputing the effects of gravity), creating a heavy fuelbed of 60-80 tons per acre. The next forest grows up through that fuelbed and the combination of heavy down fuels, residual mature trees that weren’t killed by bugs, and regeneration that will serve as ladder fuels, set the stage for intense large scale fires—not over the next few months or years as implied by the NASA piece, but over decades—40-50 years. I know the intent of these ongoing arguments is to keep management in check in the short term—so we don’t overdo the knee-jerk reaction to red trees, but the work we’ve been focusing on in the WUI is aimed at much longer term. Andy needs to look at the longer term. Bottom line is, despite high-priced NASA landsat analyses or convoluted GIS exercises, we know from real-life fire experience that a fuel model with 60-80 tons of heavy fuel per acre is going to be problematic when it eventually burns—especially in and around homes and infrastructure.
Well, I could go on and on but I’d be wasting breath…. So I’ll just say that I would never assert that BB’s cause large scale intense fires—BB’s are just one integral part of numerous extremely complex systems that also include fire.
Note: what Cal says is not very different from what I’ve been saying and what we told the local Colorado scientists at various meetings. So possibly some folks didn’t listen to what we said, or they didn’t believe us, or other places are very different from Colorado. Each possibility raises a variety of intriguing questions, IMHO.