Forests after fire
The ashen earth will eventually return to manzanita, snow brush and tall conifers as part of a cycle integral to the Sierra Nevada since long before humans arrived.
That recovery is not only important for the natural beauty that brings people to the Truckee-Tahoe area, but also affects future fires and other natural disasters.
But how the forests return to their former state has become a matter of heated debate.
Foresters, such as those with the U.S. Forest Service, draw from a long-standing tradition of carefully cultivating forests to quickly regenerate timber ready for logging, as well as using those techniques to now accelerate forest recovery to a resilient state.
“Back when the Forest Service took large cuts of trees they would go back and plant, then in a couple years go back and spray with herbicides and the trees would release,” says Scott Conway, east side forester on the Tahoe National Forest. “We realized we could use the same techniques after fires in our ecological approach.”
Bringing forests back to health faster makes them more resistant to future fires, pests and drought, he said.
On the other hand, there are biologists, ecologists and conservation groups that question the need for man to meddle in the natural recovery of a forest after the flames. The human hand, they argue, hinders biodiversity and forest health.
“The Forest Service system is 100 percent for getting commercial timber as soon as possible. It’s not an ecological approach,” says Chad Hanson, director of the John Muir Project.
The opposing views often find the two parties on opposite sides of legal battles.
But despite these seemingly incompatible approaches, both sides really want the same thing ” a healthy forest after the fire.
Tahoe Donner’s Forester Bill Houdyschell has mopped up after forest fires since 1993 in the Truckee subdivision, working both before and after burns to reduce future fire risk to 6,000 homes.
And with the Aug. 22 Interchange Fire, Houdyschell is preparing to do it all over again.
“The first thing is to not let time go by before you start doing something. If you do, the brush will compete with the seedlings,” Houdyschell says, planning to get into the recent burn in the spring.
“We’re going to masticate the dead brush, cut down most of the dead trees, but we’ll leave some for wildlife, and put the chips down for erosion,” Houdyschell explains.
In the spring of 2009, Houdyschell says his forestry department will plant seedlings then follow up with herbicides to keep the chaparral down.
“What we like to see is a mature ” like 100 years old ” forest, with a canopy that shades out the competing brush,” Houdyschell says. “What we’re doing is accelerating that process. I’d guess we can return the forest in half the time of nature, if not faster.”
On a larger scale, the U.S. Forest service employs many of the same techniques.
“In the wake of the recent fires things have been so fuels-driven, but what we are really going for are resilient forests ” resilient to fire, to bug infestations, to droughts and other catastrophes,” says the Forest Service’s Conway.
One of the blazes that sparked the change in the Forest Service’s attitude was the Cottonwood Fire, which burned 49,000 acres near Loyalton north of Truckee in 1994, Conway said.
Work after the Cottonwood Fire started with salvage logging ” taking out standing burnt trees, which Conway says makes it safer and easier to start re-planting saplings.
Then, it’s a matter of keeping brush under control, he says.
“The brush grows a lot faster than the seedlings and out-competes them for sunlight and moisture,” Conway says. “It’s my job to make sure those trees survive.”
This means cutting the brush down by hand, going through with a mastication machine and in some cases using herbicide.
“With hand-cutting and mastication the root structure remains, so the brush can just re-sprout,” explains Conway. “So it’s manually intensive and quite a bit more expensive, but not as successful as herbicides.”
This is where conflict erupts. The Forest Service’s chemical-based approach on the Cottonwood burn conflicts with the views of regional conservation groups, which resulted in a lawsuit in 2000.
“We feel the forest is recovering fine on its own,” says Don Rivenes, acting executive director of the Forest Issues Group, one of the groups that brought suit against the Tahoe National Forest.
Rivenes said that herbicides, no matter the type, pose a risk to streams and native species.
Conway says even he was leery of using chemicals at first, but was convinced after doing some research.
He says the herbicides used, which are basically the same as Roundup that can be bought at any gardening store, bind to the soil keeping them from transporting into ground water. Then they become inert after four to six weeks, Conway says.
He adds that the Forest Service goes through an environmental review, which requires herbicide use to stay away from streams and other bodies of water.
“We were allowed to do a few one-acre test plots, and the trees where herbicide was used on brush were that much bigger ” that much wider,” Conway says. “Our counts even showed more biodiversity.”
He says surveys of the test plots counted 20 to 25 species, compared to two to three species in untreated brush.
But both the Forest Service and the Tahoe Donner foresters acknowledge the need for some remaining chaparral brush for certain species.
“We want to leave some areas for wildlife, leave some brush fields as well,” says Houdyschell.
But if the forest does grow back on its own, Conway says it would be dominated by white fir instead of pine, which is less resistant to fire.
Either way, Conway says he will continue to try to re-establish pine forest, whether by hand, with machine or possibly even with goat herds.
In the end, the Forest Service’s goal is not to eliminate fire altogether from the local forests ” a mistake from early forest management still being paid for with overly dense forest ” but to keep blazes smaller and lower intensity, Conway says.
“This is a fire-adapted area, but we are seeing fires not natural in human history ” past suppression has virtually eliminated low intensity fires,” Conway says. “Trees that should still be standing after the Cottonwood Fire are gone.”
“They thought they needed herbicides for conifers to out-grow shrubs, but the conifers have done that,” Rivenes of the Forest Issues Group says. “They said they need to grow faster, but we thought the shrubs provided nitrogen to help the trees grow.”
While the Forest Service says that the brush fields that naturally follow high-intensity fires are the greater future fire hazard, Rivenes argues that the seedling plantations put in by the Forest Service are actually more dangerous in their first 20 years.
The John Muir Project’s Hanson, who has a Ph.D. in ecology, says it isn’t just a few local conservation groups that take issue with the Forest Service’s methodology.
“Over 600 scientists have signed a letter asking the Forest Service to stop,” Hanson says. “It’s rare to see that kind of consensus.”
Hanson disputes not only the agency’s techniques of salvage logging and the use of herbicides after the fire, but also takes issue with the concept that high-intensity fires should be stopped.
“A lot of people proceed with the assumption that a high-intensity fire is a destroyed area, but in fact it’s one of the two highest diversity areas along with old-growth forests,” Hanson says.
He points to a study that found a reduction in fire in the Tahoe Basin has caused a 62 percent decrease in brush fields, endangering certain species that depend on that habitat.
Brush and conifers don’t compete to the trees’ detriment either, Hanson says, and actually work together to re-introduce nitrogen into the soil, a nutrient depleted during a fire.
While the Forest Service points to more high-intensity fires in recent history than before, Hanson says that’s missing the point.
Twenty to 30 percent of fires are now high-severity in the Sierra, compared to historical numbers of 10 to 15 percent, but historically more acreage burned than today, he says.
For Hanson, it boils down to perception ” the Forest Service’s perception of the need to re-grow trees for timber, and the public’s “Smoky the Bear” perception of fire as a disaster, he says.
“The basic problem is differentiating safety and ecology,” Hanson says. “People think about a fire like they think about a house burning ” a tragedy. They think the same must apply to a forest, but it’s actually the complete opposite.”
In the end, however, Hanson said he isn’t arguing against forest management for safety.
After the initial emergency repairs and treatments to the Angora Fire, the Lake Tahoe Basin Management Unit has begun planning its next steps for the burn site, said Rex Norman, the unit’s spokesperson.
“In the Tahoe Basin we are looking for an ecosystem approach,” Norman said. “We’re not asking how we can get timber production back, we’re asking what do we want the area to look like in 100 to 150 years.”
Initial efforts include road a trail repairs to prevent erosion, and identification of hazards near urban zones, he said.
Longer-term plans for restoration are underway, and a series of options should be available for public comment by the end of fall or sometime in the Winter, Norman said.
“We will look at alternatives from doing nothing to complex solutions,” Norman said.
The restoration work itself will come after the planning process, which could take years for environmental review, Norman said.
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