Wildfire season in the Northwest started early this year. Crews recently subdued the 5,345-acre Buckskin fire near southern Oregon’s Illinois Valley.
The Buckskin fire is called a “reburn” because it’s on land that was scorched by wildfire in the recent past. These reburns are a positive indication that the forests are recovering from decades of fire suppression.
The old footprint, or scar, of the Biscuit Fire is still visible from several points, including high about the Illinois River. The landscape here is a mix of healthy-looking stands of trees, clumps of standing dead trees called snags, and low brushy places where the forest is beginning to come back.
Way off in the distance, a barely audible speck on the horizon, a helicopter flies towards the Buckskin Fire, the largest wildfire in Oregon and Washington so far this year. It’s burning right on top where the Biscuit burned 13 years ago.”
Even those working at the Buckskin Incident Command Post near Selma, Oregon sometimes conflate the two.
Jim Hampton, a fire behavior analyst with the Forest Service, said that generally where fire has previously burned, the fuels are reduced. The exception can be large unburned logs left behind.
"When you put a log on a fire, you usually put the biggest logs on right before you go to bed at night because it burns long," Hampton said. "It doesn’t spread as fast, but it creates a lot of intensity on site where it’s fallen."
There’s also the chance that the snags may fall and injure firefighters in the field. On the Buckskin, crews have been brought in to remove swaths of these dead trees.
Ecologically, those snags are important for habitat and soil nutrients. They help feed the regeneration that happens after fire moves through an area. It’s a natural process that profoundly shaped the evolution of forests in the Northwest.
The aroma of pine from shelves of wood samples permeates the air at the wildfire lab at Oregon State University.
Forestry Professor John Bailey pulls out a large oblong tree cross-section. Every ten to 20 years, part of a growth ring is blackened, likely evidence of a wildfire.
The 13-year gap between the Biscuit and Buckskin fires is about right for the forests in Southern Oregon. In that time, fuels wouldn’t have built up enough to create a serious hazard, he said.
“Now with the Buckskin, fuels aren’t too bad, weather’s not too bad," Bailey said. "We know it’s going to burn. So even from a fire management perspective, it may be time to burn the burn – rather than automatically default into suppression.”
But there are other factors that complicate Bailey’s analysis, and many have to do with what humans do to the land between burns.
Salvage logging, or cutting recently burned trees, is one of the most controversial.
Research on the Biscuit Fire shows that areas that were salvage-logged and replanted after a wildfire often burned more intensely than areas where snags were allowed to remain. This counters long-standing claims that salvage logging made wildfires easier to fight.
Bailey said there are valid arguments for salvage logging, but those have less to do with fire control and forest health. "All the compelling reasons to salvage are economic and societal.:
After decades of human suppression of wildfire, the forests in the Northwest are beginning to behave naturally once again - burning often, but with less severity.
And relatively minor blazes like the Buckskin, burning on fire scars of the past, are an excellent indication that in some places, we’re already there.
Copyright 2015 EarthFix
