When the Rim Fire blackened about 400 square miles of rugged, wild county at the west entrance to Yosemite National Park last year—including some of the park itself—the predictions for the aftermath were mostly dire.
The fire was one of the largest in recorded California history and pundits and the media predicted massive erosion, a loss of animal habitat, and fouled rivers and streams.
Not so fast, said ecologist Dr. Chad Hanson, who spoke Tuesday at the Sierra Nevada Aquatic Research Laboratory’s Green Church before a packed house.
One at a time, the UC Davis doctoral graduate and former law school graduate dispelled what he said were old and outdated ideas regarding the impacts of fire.
Before he was done, he had thrown much of the conventional wisdom regarding big fires on its head.
First and foremost, he said, the Rim Fire did not burn enough acreage, hot enough, to do the kind of damage most people think. Instead, much of the acreage reported to be hit by “high severity” fire was not, due to the fact that aerial mapping used to make the measurements did not show all of the on-the-ground reality.
“Of the 257,000 acres that were burned, only about 49 percent was conifer forest and of this, about one third of it burned at a high intensity,” he said, noting he and other researchers had walked much of the area the fire burned.
Hanson said he uses the word “high intensity” instead of the more common term, “high severity.”
High intensity is defined as a forest where “most or all” of the trees are dead, he said.
“What we found was that much of the foliage said to be dead was not,” he said.
“In fact, right now, we are seeing many trees that have been counted as being dead, ‘flushing,’ or putting forth new needles. It’s happening to an extraordinary degree on the Rim Fire. I was shocked.”
The trees survived, even with most of their needles brown and dead-looking, because enough of the “terminal buds” at the apex of the tree survived the fire. The new growth is coming from these terminal buds, he said.
Another common belief in the fire world is that the interior of a big fire cannot re-seed itself and thus regenerate, because the interior is so far from the outside boundaries of the fire. Wind and animals that normally carry unburned seeds from outside of the fire perimeter cannot surmount the large distances to the interior of the fire, many believe.
That too, was not true in many cases in the Rim Fire, Hanson said.
“Wind is only one way to get seeds in. Birds are another and we found that the interior of the fire is being re-seeded in many places.”
Third, much of the forested area burned in the Rim Fire occurred in what Hanson calls the “montane chaparral” type of forest—characterized by shrubs such as white thorn and trees such pines. This kind of forest includes what Hanson said is one of the richest and most diverse forest ecosystems in the state, often matching or surpassing the biodiversity of old growth forests, which are often considered to be the most diverse and species-dense kind of forest.
“When this forest burns, it creates what we call a ‘snag forest’ habitat,” he said. “In many cases, the biodiversity in these areas grows every year for decades after a fire and the research shows it can have the biodiversity of an old growth forest, or even more biodiversity.”
The problem is, this kind of forest has almost no protection of any kind, he said.
Despite these factors, the Stanislaus National Forest, which manages most of the acreage burned by the Rim Fire, plans to expedite clear-cut logging (for profit) on much of the burned, forested areas of the Rim Fire beginning this spring, he said.
If the main priority is to get the fire salvage funds from logging the Rim Fire into forest coffers, a clear-cut makes sense.
If biodiversity and ecosystem recovery—saving imperiled species such as the black-backed woodpecker and others common to the snag forest—is the top priority, logging is the last thing that should occur, he said.
The logging will be done by heavy machinery, not aerially, and the new roads needed and the forest’s plans to replant the area for commercial timber harvesting in the future will contribute to the very erosion and other negative effects that the forest and media ascribe to the fire itself, Hanson said.
On top of that, the plans to log the Rim Fire are imminent.”
“The 30-day comment period on this started this week and there are no appeals allowed on this kind of decision,” he said.
The forest made its decision despite a letter sent to Congress written by Hanson and signed by more than 250 scientists protesting the premises of “post-fire” logging in places like the Rim Fire.
The May 13, 2014 Rim Fire Recovery update can be found here.
The draft Environmental Impact Statement can be found here.