by Kimi Eisele
It’s been a hot summer in the United States. Literally. As of this writing, 110 large, still-active fires have burned 2.2 million acres, mostly in the American West.
Given that fire can devastate landscapes, lives, and livelihoods, it’s hard to think of it as “good.” But fire ecologists and historians say there is good fire and bad fire. Understanding the difference might be its own kind of folklore.
“We think of wildfire, we think ‘dangerous’,’ said Stephen Pyne, a fire historian at Arizona State University and the author of over 30 books, most of them about fire. “But is there anything more homey, literally, than a hearth, where the family and the familial gods gather? That’s where you gather around to tell stories. That’s where culture gets passed along.”
Fire is fundamental to who we are and how we express ourselves, Pyne said. “Fire regimes are as much an expression of who we are as novels, architecture, or our choice of technology.
More than that, though, he says, “Fire is not a thing, it’s a reaction.”
And how we react to that reaction says as much about us as any other of our cultural expressions.
“We have to make choices about fire, because we will always live with it,” Pyne said. “What we choose is an expression of our society and values. Are we going to work with it or eliminate it?”
Fire as Relationship or Resource
Beyond the hearth, fire has long been used across the globe as a way to boost soil nutrients and promote the growth of preferred plants in the landscape. Known as slash-and-burn or swidden agriculture, this form of land management and agriculture is still used today in many parts of the world. In the United States, indigenous people similarly used fire to support agriculture and manage landscapes.
But in early modern European societies, fire was viewed as a form of chaos and disorder, associated with peasant classes who used such fire-fallow practices, as Pyne has noted. (The word “curfew” comes from the French couvre feu, to cover or douse a fire.)
As European settlers colonized America, they took control of indigenous lands, viewing timber as an economic resource to be extracted and fire something to be eliminated, a notion that has dominated forest management practices through much of U.S. history.
“We’ve developed this notion of fire as dangerous or bad,” said Tyson Swetnam, a former wildland firefighter and fire management specialist, and now a data scientist at the University of Arizona. “Especially in the Southwest.”
In other areas of the country, such as the South, this is less the case. “The longleaf pine, for example, is adapted to a regular burn cycle and needs fire to thrive. The landscape is wet, so the fires there are not raging,” he said.
Many people in the South are accustomed to the practice of burning, Pyne said. “They’ll tell you things like, ‘I went out with my granddad and he showed me how to burn this off.’ It was built into the folklife.”
California, too, has a fire folklife. “There you hear stories about going out with dad or granddad, but it’s about putting fires out,” Pyne said.
A Century of Fire Suppression
In the summer of 1910, a series of large fires swept across Idaho, Montana, and Wyoming. Drought conditions and high winds fueled the fires. The “Big Blowup,” as it was called, collectively burned over 3 million acres of land, killing 78 people.
To avoid a repeat catastrophe, Congress doubled the budget of the U.S. Forest Service in 1911, only six years after it was founded, and it initiated an aggressive fire prevention and suppression policy to ensure the protection of public and private land, timber, and human lives.
“They called it the 10 a.m. policy,” says Thomas Swetnam, a fire ecologist and professor emeritus at the University of Arizona Laboratory of Tree-Ring Research (and Tyson’s father). “They would do everything they could to put fire out by 10 a.m. the next day, or 10 a.m. the following day.”
The effort succeeded in reducing the amount of acres burned each year and protected lives and property, said Lincoln Bramwell, chief historian for the U.S. Forest Service. But it had other consequences.
For one thing, the culture of fire suppression brought significant changes to the American landscape.
“By the 1930s you start to have hundreds and hundreds of men in the woods building fire cabins and lookout towers and infrastructure to put fires out,” Thomas said.
In the years after World War II, surplus military aircraft found their way to the U.S. Forest Service, which began to use helicopters and slurry bombers for fighting fire, he said.
But the lack of burning over decades resulted in forests filled with “fuel,” meaning understory shrubs, dead trees, and younger trees that ignite easily.
“Today you see ‘dog hair’ thickets where there’s 10,000 small stem trees, where there would have been 10 or 20 large old growth trees in the past,” Tyson said.
Such thickets pose fire threats to otherwise healthy forests. Which is why using controlled fires, or prescribed burns—“good fire”—to eliminate these fuels can make forests less susceptible to larger fires.
“Part of why today’s fires are so out of control is because we are also afraid of using fire as a tool,” Tyson said.
He recalls an example from his time as a firefighter working in the Rincon Mountains of Saguaro National Park, east of Tucson, in the early 2000s. One fall, they did a prescribed fire on the mountain, but excluded an area of old growth Douglas fir and ponderosa pine where there was Mexican spotted owl nesting habitat. The next summer lightning started a wildfire on the forested slope below the owls’ grove. The first night the fire burned 50 acres, and the firefighters were unable to contain it. “When it hit the owl PAC [Protected Activity Center] the next day, it nuked it. When it hit the prescribed fire area, it dropped to the ground as a surface fire,” Tyson said. Fortunately, the owls survived the fire, he added.
Opposition to prescribed burning comes from all sides of the political spectrum, Tyson said, as well as from government budget offices. In order to thin forests, managers need an approved plan, which goes through an environmental impact assessment. If endangered species are present in areas where thinning trees is necessary, lawsuits can happen. On the other side, people don’t want to lose the resource, the timber, Tyson said. “So there are a lot of gray areas.”
Also, fighting fires is expensive. “Fire can cost upwards of $100 million to suppress. Never mind property losses. So when foresters go back for money for treatment or thinning, they often don’t get it.”
The policy of suppression also caught the Forest Service in a bind, Bramwell said.
“The Forest Service strives to serve the public even when it knows it cannot keep reducing the amount of acres burned or the number of structures lost each year, as more and more Americans move their residences into historic fire regimes. The issue is more cultural and political than it is scientific,” he said.
Fire in the Southwest
While fire was absent from Western landscapes for over a century, this wasn’t always the case. For hundreds of years, significant burns happened frequently, once or twice per decade in some pine forests, fire ecologists and historians say.
In studies funded by U.S. Forest Service and National Park Service, Thomas and colleagues have used tree-ring data—the science of dendrochronology—to piece together a long history of fire events in the Southwest borderlands, particularly in the sky islands (isolated mountains within lowland deserts of northwestern Mexico and the southwestern United States).
“These were low intensity fires, burning just through the understory, and widespread in most mountain ranges,” Thomas said.
Ponderosa pine trees are well adapted to fire, as they can incur injuries at their base and then heal over completely. “So we’re looking for fire scars left in trees, old veteran ponderosas that withstood many fires in the past. We found 10 or 20 different fires recorded in a tree,” Thomas said.
Jesse Minor, a geographer at the University of Maine at Farmington has used tree ring samples from the Chiricahua Mountains of southern Arizona to piece together a narrative of fire use by indigenous people.
While there’s evidence of fire before 1690, Minor said, indicating early indigenous peoples used it, “There’s an uptick in fires with the Apache.”
Ethnographic records suggest Apache people used fire to promote edible and medicinal plants. And while their structures, made of branches and brush, were flammable, “Apaches were really good at fire control,” Minor said.
The Apache also used fire as a wartime tactic, Minor said, burning ground around natural springs to deplete forage for Spanish horses. This was a tactic the Spanish also used. “They would burn up-canyon to flush the Apaches out,” he said.
The widespread evidence of fire in this time period suggests a healthy relationship with it, Minor said. “When Europeans got to the continent, they arrived to a landscape crafted and maintained by indigenous people. These anthropogenic ignitions helped maintain the forests.”
While lightning explains some of the fire prevalence, evidence of burning occurs in spring and fall months as well. “No doubt the Apache people were manipulating fuel with fire also,” Thomas said.
But by the early part of the 20th century, the tree-ring data shows that the frequent fires suddenly stop.
Intensive grazing by introduced sheep and goats eliminated fine grassy fuels and created firebreaks with trails and roads. At the same time, the Apache were forced off the land by the U.S. military. “It was a combination of the removal of native people and the introduction of livestock that meant a sudden decline of burning. The frequency goes almost to zero,” Thomas said.
After World War I, the wool market collapsed and the livestock industry lost footing in the Southwest until the rise of cattle ranching. By then the policy of active fire suppression by the U.S. government was in full swing.
Not so in Mexico. Thomas said the borderlands offer a key site for comparative studies of fire policy. Unlike in the United States, fires continued to burn in northern Mexico well into the 20th century, particularly in remote mountain ranges, as a result of ongoing interactions between people, fuels, and climate. There, a livestock industry didn’t take hold until later and there was no fire suppression policy.
“If you go 100 miles south of border, you can find pine forest fires that have continued to burn without interruption. In more remote areas of Sierra Madre, you can still find frequent fire regimes,” Thomas said.
“Holocaust” Fires and the End of Forests
Ecology, fire research, and fire history helped land managers understand the benefits of fire in the landscape.
By 1968, the National Park Service began using prescribed fire and allowing fires caused naturally to run their course, if not threatening human settlements. The Forest Service followed suit in 1978, said Bramwell. “Despite the plans of fire policy on paper, the Forest Service is still bound to serve the public and its representatives in Congress who both demand fire protection in the form of suppression,” he added.
For more than 120 years, there was a deficit of fire in the landscape of the American West. “Until now, when we see enormous holocaust fires wiping out whole forests,” Thomas said. “The intensity is off the charts.”
Today’s massive fires in California are driven in part by conditions in the antecedent year (which, if wet, can result in excessive vegetation), current conditions, and an extreme weather event, usually a high- or low-pressure system, which can bring high winds.
“You can have hundreds of small fires burning across a region, and then a major weather event surfaces and they’ll all grow and suddenly you’ll have complexes of fires all expanding, sometimes burning together into single large fires,” Tyson says.
Before 1985, a large fire in the Southwest was 10,000 acres. “After 1990 and 2000, a 10,000-acre fire is nothing. We started to see 400- and 500,000-acre fires. Despite all the technology, those kind of fires are very hard to fight,” Thomas said.
With predicted hotter and drier temperatures due to climate change, it’s likely to only get worse, he said.
“Is it fuels or climate change? It’s both,” Thomas said. “Forests have increased in density and fuels. Add onto that extraordinary hot drought, you get a combination where you can’t control these fires.”
And that might mean the end of forests as we know them.
With such large areas burning, there’s often not a seed source for trees to reestablish. Increasing temperatures make life harder for trees in open patches. And repeated high-severity fires within a landscape means the trees can’t recover.
“It does seem to be the trajectory that forests are changing in a way they won’t recover back. Many places may not go back to forest at all,” Thomas said.
His son agrees. “We’re in a position where we could lose all of our forests in the west. You’ll have a complete reorganization of those ecosystems,” Tyson said.
Some stands of trees will become shrub fields or grasslands. Others could “migrate.” “Forests you expect at certain elevations, such as Subalpine Fir (Corkbark fir), will slowly die off and emerge on north aspects, or 5000 meters higher up in elevation. They’ll move up until they run out of mountain,” Tyson said.
Watersheds will also be impacted. As forests burn, they leave landscapes open to flooding and debris flows. Severe floods can erode canyons and hillsides, with lasting repercussions for communities and agriculture.
And how do a former firefighter and a forest researcher feel about these changes?
“On one level it’s a sadness because I love old trees and ancient forests,” Thomas said. “The landscape will change, and there’s a lot to like about those new landscapes. There are lots of bird species in grasslands, for example. But it depends on human perspectives. What do you want? What do you value?”
“It’s hard to express,” Tyson said. “Nobody mourns mammoths or ground sloths. My children aren’t going to know there were trees the size of this table here. They’re going to see young aspen, 20 to 30 feet tall and they’re going to be beautiful every fall. But that’s very different than seeing a stand of 150- to 200-foot-tall old growth trees.”
Stephen J. Pyne. 1997. World Fire: The Culture of Fire on Earth. University of Washington Press.
Stephen J. Pyne. 2015. Between Two Fires: A Fire History of Contemporary America. University of Arizona Press.
Jesse Minor & Geoffrey Boyce. 2018. “Smokey Bear and the pyropolitics of United States forest governance.” Political Geography 62, 79e93.
by Kimi Eisele