This is an interesting story because it’s in Grist, and there are some great photos. It’s interesting to reflect on different researchers and what they use as evidence to support their conclusions, and how broadly they think they apply
“We have overwhelming evidence that when we treat forests by removing fuels, it generally — not always, you can never say always, but generally — moderates fire behavior,” said Maureen Kennedy, a professor who studies forest fires at the University of Washington, Tacoma.
Kennedy studied a similar situation as the one unfolding in the Sycan Marsh, following the 2011 Wallow Fire in Arizona. She looked closely at the places where people had thinned the forest around two small towns, Alpine and Greer, preparation that probably saved them. Forest treatments like this work by spacing out fuel, Kennedy said. When there is a continuous ladder of branches and small trees from the ground to the canopy, it allows fire to rise up into the treetops. And when trees are close together, fires move from one to the next, growing hotter and hotter. Trees that are farther apart, however, encourage fires to fall to the ground. It makes sense, intuitively, but it’s still surprising when a wall of flame settles down and begins creeping across the forest floor, Kennedy said.
“No matter how many times I study it, no matter how much sense it makes in theory, it’s still amazing,” she said. “When you look at photographs from the Wallow Fire, that landscape was nuked, it was burning so hot that there were only blackened sticks that used to be trees left behind. Then, as you move into the treatment area the trees are brown, and then further in, they are green.”
You can see the same thing in a photo (below) taken after the 2020 North Complex Fire, near Quincy, California. There, too, the fire mellowed when it reached the area where workers had removed fuels, said Hannah Hepner, program manager for the Plumas County Fire Safe Council.
”That aerial photo is pretty incredible, and that is precisely where the fuels treatment took place,” Hepner said. But, she cautioned, these images shouldn’t set expectations too high: Fire behavior is unpredictable, and some areas always burn more severely than others. Just across the street from that photo, she said, the fire continued to blacken trees — though even there, previous forest management allowed firefighters to get down a narrow road and save a wood shingled building.