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Can 'active forest management' really reduce wildfire risk?

by AMANDA EGGERT Montana Free Press
| September 1, 2021 2:20 PM

With two active disaster declarations underway — one for drought issued on July 1 and another for wildfire on July 14 — Gov. Greg Gianforte is in the thick of a crisis response that's expected to continue for at least another month, maybe two, according to the most recent wildfire forecast.

Along the way, he's had ample opportunity to stump for "active forest management" to mitigate wildfire risk and reduce carbon dioxide emissions entering the atmosphere through wildfires. Those emissions are considerable: According to the Global Fire Emissions Database, California's 2020 wildfire season produced an estimated 91 million metric tons of carbon dioxide, which exceeds the state's annual CO2 emissions from power production by about 30 million metric tons.

Active forest management has been a cornerstone of Gianforte's response to wildfire, and something he highlights as part of his approach to climate change. On June 9, Gianforte directed the state Department of Natural Resources and Conservation to double the number of acres treated with some mix of logging, thinning or prescribed burning. On July 14 he announced that the state has approved 14 such projects under the Montana Forest Action Plan.

"The reality is, if you thin a forest, everybody wins," Gianforte told the Montana Free Press in a late-July conversation about climate change. "We get more habitat, there's more wildlife, there's more recreation. The forest becomes more resilient to wildfire. … it doesn't burn as hot and it doesn't burn in the crown."

As with conversations about natural resource management more broadly, public discourse about whether forests can be managed to effectively reduce wildfire risk is incredibly heated. Like Gianforte, U.S. Sen. Steve Daines frequently calls for active forest management and reform of the environmental review process to address "catastrophic" and "deadly" wildfires. During a recent wildfire briefing hosted by Gianforte, Daines said "frivolous litigation" has tied up thinning projects in courts and caused the U.S. Forest Service to fall short of its timber harvest targets in Montana.

Conservation groups like Alliance for the Wild Rockies, on the other hand, say such rhetoric is designed to play into public fear of wildfire, and that the real motivation behind elected officials' calls for active forest management is more complicated. AWR Executive Director Mike Garrity told the Free Press politicians "have lots of different excuses to manage forests in the backcountry," but what they really want is to "subsidize the timber industry."

Consensus among scientists who study the intersection of forest management and wildfire for a living can be hard to find. Some advocate aggressive forest management to deprive wildfires of fuel. Others call for targeted thinning and burning to mimic the role fires historically played on the landscapes of the American West. Still others say wildfire is a natural process, and argue for less human intervention in forested landscapes.

Researchers with the Forest Service and the University of Washington recently released a review of research on the question in the journal Ecological Applications, arguing that thinning and prescribed burning can effectively mitigate wildfire risk, and that such treatments are necessary to reduce fuel loads that have accumulated after a century of land management that heavily favored suppression.

"Due to altered stand conditions, restoring an active fire regime and reducing climate vulnerability often requires either a managed wildfire that significantly thins forests, consumes fuels, and favors fire-resistant, larger trees, or coupled mechanical thinning and prescribed or cultural burning treatment followed by regular maintenance burning," the study's authors argue.

Other scientists, including ecologist George Wuerthner, who's written two books on wildfire ecology and policy, say it's misguided to hyper-focus on the fuel piece of the wildfire equation without acknowledging the role short-term weather events and long-term climate trends play. Wuerthner, who splits his time between Livingston and Bend, Oregon, argues that if fuel were the most important factor driving wildfires, North America's fecund coastal forests, which boast some of the densest biomass on the planet, would be seeing frequent, high-severity fire. But he said that generally hasn't been the case.

After visiting a number of headline-making wildfires over the past three decades, Wuerthner said, he's seen over and over how certain blazes are able to burn right through areas that have been treated with logging, thinning or prescribed fire. When the right mix of wind and hot, dry air saps moisture out of grasses, brush and trees, fires blow right through clearcuts, even.

He said he's seen that in the deadly Camp Fire that leveled Paradise, California, in 2018, and closer to home at the Jocko Lakes Fire that burned more than 36,000 acres outside of Seeley Lake in 2007. This year's examples include central Oregon's Bootleg Fire and California's Dixie Fire, which have burned a combined total of more than 1.1 million acres. The Bootleg Fire burned more than 413,000 acres before it was contained earlier this month. Some conservationists say extensive logging and thinning inside the fire's perimeter, far from slowing its spread, helped fuel its advance to become the third-largest wildfire in Oregon's history. Wuerthner makes similar claims about the Dixie Fire, which as of Aug. 27 has burned more than 750,000 acres west of Chico, California, and is 46% contained.

"We have all these examples all around the West where active forest management didn't work, but we keep hearing that it did," Wuerthner said. "At what point do you maybe question your assumption?"

Wuerthner said Montana would be better served making its communities more fire-adapted by focusing mitigation efforts in areas immediately around the built environment. Those efforts start with people being more selective about where they build — a prospect that's taken on urgency as development in what fire managers call the Northern Rockies' Wildland-Urban Interface, or WUI, continues to expand.

Best practices for reducing wildfire impacts to communities

Mitigating wildfire impacts by reducing home losses is one area where scientists and politicians find common ground. Programs like FireWise USA, which helps individuals and communities protect against structure loss by assessing ignition potential and working with property owners to decrease it, enjoy widespread support in both policy and research circles. But when it comes to active forest management, the farther from a community a proposed logging, thinning or burning project is, the more controversial it becomes.

University of Washington-Tacoma professor Maureen Kennedy, who develops computer models to understand the efficacy of fuel reduction treatments, says frontcountry treatments stand to lose some of their benefit if backcountry management isn't also part of the discussion. A fire that starts in a thickly forested area can gather a head of steam that it carries into a treated landscape, weakening the buffering effect of the fuel reduction, she said. She also argues that the coming decades might require more human intervention — more thinning and prescribed fire — to address accumulated fuel-loading, but that at some point those landscapes could become self-sustaining if land managers and the public develop a greater tolerance for letting backcountry fires burn and intentionally introducing prescribed fire under the right conditions.

She said the best solution is "often fire itself," and given the right mix of tailored fuel treatments and fire, the hope is that even forests with lots of accumulated fuel "could maintain themselves eventually."

That approach is positioned to receive a significant injection of federal cash if the infrastructure deal the U.S. Senate passed earlier this month becomes law. Montana U.S. Sen. Jon Tester said the plan designates $3.37 billion for wildfire risk reduction nationally, which includes $500 million for forest thinning and another $500 million for prescribed burning.

But to Wuerthner's view, removing fuel in a forest to prevent wildfire carries the risk of increasing the flammability of remaining fuels by exposing them to the drying effects of sunlight and wind.

"The wind can go through a thinned forest much more easily than a dense forest," he said, adding that an increase in wind speed can exponentially increase a fire's rate of spread.

Wuerthner also argues that there's a scale issue presented by approaches that favor widespread logging or thinning, given the sheer size of the forested landscape and the random nature of lightning-ignited fires, which account for 46% of fire starts on national forests, according to the Forest Service.

A 2017 paper published in the Proceedings of the National Academy of Sciences reviewed the amount of federal land that received mechanical fuel treatments — projects that involve heavy machinery like feller bunchers — and compared it with the number of acres that burned in the following 10-year period. Ten percent of the acreage that was mechanically treated actually burned during that period. The authors concluded that "forested areas considerably exceed the area treated, so it is relatively rare that treatments encounter wildfire," and that given the limited time for which a treatment retains its effectiveness — generally 10 to 20 years without maintenance — "most treatments have little influence on wildfire."

Authors of that study argue for an "adaptive resilience" approach that involves a shift away from all-out fire suppression in favor of a strategy that includes public education demonstrating "the inevitability of living with increasing fire in the West" and prescribed fire and managed wildfire.

Building fire-adapted communities and engaging in efforts to "harden" homes to wildfire is a strategy researchers have been advocating for decades. Such efforts involve removing or replacing potential fuel sources in the area directly around a house — anything from propane tanks and wooden decks to cedar-shake roofs and flammable landscaping. It also means reducing the likelihood that a burning ember could become sucked into a home through an unscreened attic vent or a dog door.

Creating what's known in the field as a "defensible space" around a home is also part of the picture. That means removing some or all flammable vegetation — bushes, young trees, low-hanging branches, etc. — in the "home ignition zone" 100 to 200 feet beyond the home.

Dominick DellaSala, who studies forest and fire ecology for conservation nonprofit Wild Heritage, said forest thinning can effectively mitigate wildfire risk to homes, but "we need to be surgical about it." That means focusing treatment in the areas with structures you're trying to protect and leaving more mature, fire-resistant trees standing for canopy cover. He also notes that such treatment doesn't double as a money-making venture, because the smaller trees removed in those sorts of projects typically don't appeal to lumber mills.

Following a thinning treatment with prescribed fire markedly increases its efficacy and also happens to be one of the more cost-effective tools at land managers' disposal, according to Phil Higuera, a fire ecologist at the University of Montana's W.A. Franke College of Forestry and Conservation.

Higuera also said it's important to acknowledge that thinning isn't effective under all conditions, and that policy makers should be candid about what the public can expect from them. He likens a thinning project to a levee built for a particular set of circumstances. It might prevent flooding most of the time, but it doesn't guarantee indefinite protection.

Seeing the forest for the trees

Another complexity that's often overlooked in political discourse about wildfire is that thinning is better suited to some landscapes, like the dry ponderosa pine forests of western Montana, than to others, like higher-elevation mixed conifer forests densely populated with species like subalpine fir and lodgepole pine. The former have adapted to more frequent lower-severity fires, whereas the latter are typically wetter, and evolved with less-frequent, higher-severity fires that take off when conditions are primed for it — historically at century rather than decade intervals.

The Yellowstone fires of 1988 provide a good example of high-severity fire in a high-elevation forest. When wildfire comes through those systems, in those conditions, it's often a "stand replacing" event, meaning many trees won't survive the fire and the forest will probably look considerably different for some time. Fire ecologists have come to understand that stand-replacing wildfires aren't any less integral to those ecosystems than lower-severity fire, and are in fact a rich driver of biodiversity, DellaSala said. Humans are just less accustomed to them because of the time scale involved.

Managing wildfire risk in high-elevation forests is a more complicated prospect than managing in lower, drier forests, Higuera said. Restoring the ecological role of fire in high-elevation forests requires developing a tolerance for higher-severity fire, which generally means nearby residents must tangle with both smoke and the possibility of flames encroaching well into the WUI.

Managing for the alternative — less fire in the landscape via fuel reduction — also involves tough choices. That might mean cutting down all of the trees in a big swath around a community, as is done in some communities surrounded by boreal forest in Canada.

"It's almost an all-or-nothing situation there," Higuera said. "You can't remove 20% of those lodgepole pine trees and then walk away and say, 'there won't be a high-severity fire here.'"

A common theme in conversations with researchers is that blanket statements and monolithic strategies shouldn't be driving forest management and wildfire response in Montana.

"(With) fuels in forest management, it really is a question of place," Kennedy said. "Every place tells its own story. We really need to understand different places to do effective management."

"None of these things are black-and-white. There's nuance, there's a lot of variability," said Mathew Hurteau, a University of New Mexico biology professor and one of the authors of the University of Washington and Forest Service study that examined research on the efficacy of fuel treatments. "If you have a political megaphone, it's in part your responsibility to learn about (the nuances) and help your constituents understand the choices that we face and the risks that we face."

Another common theme espoused by researchers is that curbing greenhouse gas emissions to address the factors driving the increasing size and severity of wildfires should be a foundational piece of policy makers' response, because drought, wildfire and climate change are connected. It's not coincidental that Montana is in the midst of an especially active fire season — to date, 2,130 fires have burned more than 826,000 acres, the most since 2017 — at the same time that 98.7% of Montana is in severe drought.

Policy makers have to address the wildfire issue at the "level of root causality," DellaSala said. "It's getting off fossil fuels and storing more carbon in (ecosystems). It's treating our atmosphere holistically, instead of as a dumping ground for emissions."

Even with immediate, aggressive action, it will take generations to level out the carbon in the atmosphere and restore the climate to the conditions humans prospered under for the past 10,000 years, he said.

"We don't get out of this overnight, but we've got to start getting out of it now," he said. "Or it's going to get a heck of a lot worse."