Intentional Forest Fires Shaped Forests in the USA More than Climate Change

Intentional Forest Fires Shaped Forests in the USA More than Climate Change

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New research suggests that the Eastern United States’ forests have been transformed more by Native American intentional forest fires in the past than by current climate change. But the ‘fire-adapted’ tree species that increased alongside the deliberate burnings are now in decline.

Native Americans' use of fire to manage vegetation in what is now the Eastern United States was more profound than previously believed, according to a Penn State researcher who determined that forest composition change in the region was caused more by land use than climate change .

"I believe Native Americans were excellent vegetation managers and we can learn a lot from them about how to best manage forests of the U.S.," said Marc Abrams, professor of forest ecology and physiology in the College of Agricultural Sciences. "Native Americans knew that to regenerate plant species that they wanted for food, and to feed game animals they relied on, they needed to burn the forest understory regularly."

‘Indian by Firelight’ by Eanger Irving Couse. "Native Americans knew that to regenerate plant species that they wanted for food, and to feed game animals they relied on, they needed to burn the forest understory regularly."

Intentional Forest Fires and Fire-Adapted Trees

Over the last 2,000 years at least, according to Abrams -- who for three decades has been studying past and present qualities of eastern U.S. forests -- frequent and widespread human-caused fire resulted in the predominance of fire-adapted tree species. And in the time since burning has been curtailed, forests are changing, with species such as oak, hickory and pine losing ground.

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"The debate about whether forest composition has been largely determined by land use or climate continues, but a new study strongly suggests anthropogenic fire has been the major driver of forest change in the East," said Abrams. "That is important to know because climate change is taking on an ever larger proportion of scientific endeavor."

A forest fire. ( Pixabay License )

Differences in Forests and Climate Change Across the Country

But this phenomenon does not apply to other regions, Abrams noted. In the western U.S., for example, climate change has been much more pronounced than in the East. That region has received much more warming and much more drought, he explained.

"Here in the East, we have had a slight increase in precipitation that has ameliorated the warming," said Abrams.

To learn the drivers of forest change, researchers used a novel approach, analyzing both pollen and charcoal fossil records along with tree-census studies to compare historic and modern tree composition in the forests of eastern North America. They looked at seven forest types in the north and central regions of the eastern United States. Those forest types encompass two distinct floristic zones -- conifer-northern hardwood and sub-boreal to the north, and oak-pine to the south.

Pollen and tree survey map. ( Marc Abrams / Penn State )

The researchers found that in the northernmost forests, present-day pollen and tree-survey data revealed significant declines in beech, pine, hemlock and larches, and increases in maple, poplar, ash, oak and fir. In forests to the south, both witness tree and pollen records pointed to historic oak and pine domination, with declines in oak and chestnut and increases in maple and birch, based on present-day data.

"Modern forests are dominated by tree species that are increasingly cool-adapted, shade-tolerant, drought-intolerant pyrophobes - trees that are reduced when exposed to repeated forest burning," Abrams said. "Species such as oak are largely promoted by low-to moderate-level forest fires. Furthermore, this change in forest composition is making eastern forests more vulnerable to future fire and drought."

“Oak trees are largely promoted by low-to moderate-level forest fires.” ( CC0)

Population Impacted Intentional Forest Fires

Researchers also included human population data for the region, going back 2,000 years, to bolster their findings, which recently were published in the Annals of Forest Science . After hundreds of years of fairly stable levels of forest fires caused by relatively low numbers of Native Americans in the region, they report, the most significant escalation in burning followed the dramatic increase in human population associated with European settlement prior to the early 20th century. Moreover, it appears that low numbers of Native Americans were capable of burning large areas of the eastern U.S. and did so repeatedly.

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After 1940, they found, fire suppression was an ecologically transformative event in all forests.

"Our analysis identifies multiple instances in which fire and vegetation changes were likely driven by shifts in human population and land use beyond those expected from climate alone," Abrams said. "After Smokey Bear came on the scene, fire was mostly shut down throughout the U.S. and we have been paying a big price for that in terms of forest change. We went from a moderate amount of fire to too much fire to near zero fire - and we need to get back to that middle ground in terms of our vegetation management."

Smokey the bear.

Also involved in the research was Gregory J. Nowacki, with the Eastern Regional Office, U.S. Department of Agriculture Forest Service. The Agricultural Experiment Station of Penn State funded this research.

Indiana’s Future Forests: A Report from the Indiana Climate Change Impacts Assessment

Over the next century, rising temperatures and changing precipitation patterns across the Midwest will likely have widespread consequences for Indiana's forests. Expected changes include shifts in the distributions and abundances of trees, understory plants and wildlife, as well as changes in the environmental, economic and cultural benefits these forests provide.

This report from the Indiana Climate Change Impacts Assessment (IN CCIA) examines the direct and indirect impacts that climate change is expected to have on Indiana's forests. The report specifically addresses forest regeneration, forest composition, tree growth and harvest, wildlife habitat and forest products. The findings presented here are based primarily on the IN CCIA Forest Ecosystem Working Group technical report (Phillips et al., in review) and the IN CCIA report Indiana's Past and Future Climate (Widhalm et al., 2018).

Predicting the future of a complex ecosystem with hundreds of interacting species is challenging, even under stable conditions. But conditions are not stable. Indiana's forests are living through simultaneous changes in climate, the concentration of carbon dioxide (CO2) in the atmosphere, exposure to atmospheric pollutants that can damage or fertilize trees, management practices and other factors. Even a single change, such as an increase in temperature, has consequences that ripple through the system. Because both forests and the changes in climate and atmosphere are complex, the results described in this assessment are necessarily more qualitative than quantitative.


Increasing forest fuel aridity with climate change may be expanding mid-to-high-elevation forests' vulnerability to large, severe, and frequent wildfire. Long-lasting changes in forests' structure and composition may occur if dominant tree species are poorly adapted to shifting wildfire patterns. We hypothesized that altered fire activity may lower existing forest resilience and disrupt the recovery of upper-montane and subalpine conifer forest types. We empirically tested this hypothesis by quantifying post-fire forest structure and conifer tree regeneration after spatially large, severe, and rapidly repeated wildfires (<12-yr interval) in the Central Cascade Range in the U.S. Pacific Northwest. Post-fire conifer regeneration was generally very poor among plots that experienced either a single high-severity fire or rapid reburn, driven primarily by lack of proximate seed source. Pre-fire dominant, shade-tolerant species' abundance was highly negatively correlated with increasing seed source distances and dry, exposed post-fire environmental conditions. In rapidly reburned plots, the order of burn severity was critical and promoted establishment of all conifer species, if low-then-high severity, or primarily fire-adapted pines, if high-then-low severity. Our findings suggest that these forests, affected by expansive high-severity and/or short-interval wildfire, may transition into a patchy, low-density, pine-dominated forest state under future warming trends. These emerging, early seral ecosystems will incorporate more fire-adapted tree species, lower tree densities, and more non-forest patches than prior forests, likely expanding their resilience to anticipated increases in fire frequency. If future larger, more severe, and more frequent wildfire patterns manifest as expected in the Cascade Range, previously denser, moist mid-to-high-elevation forests may begin resembling their drier, lower-elevation mixed-conifer counterparts in structure and composition.

A shared appreciation

The third episode of the series recently premiered at the National Museum of African American History and Culture. The crowd of about 350 people included several environmental lawmakers.

"The three episodes currently airing — Colorado, Oregon and South Carolina — have been widely acclaimed by conservationists, the wood products community, re-creationists and government agencies," says Ward, who is also founder and President of Choose Outdoors. He shares executive producing duties with Kate Raisz, an award-winning filmmaker who has decades of experience making television programs for PBS and other networks.

"We hope viewers will come to understand the considerable progress has been in developing collaboration amongst the many forest stakeholders."

Stop Blaming Climate Change For California’s Fires. Many Forests, Including The Redwoods, Need Them.

Forests, including the redwoods, need periodic fires to create new life.

Fires have burned 1.3 million acres of California’s forests over the last month. That’s one million acres more than burned last year, and is an unusually high number for this early in the fire season.

California political leaders including Governor Gavin Newsom and Senator Kamala Harris, the Democratic vice presidential candidate, blame climate change.

“If you are in denial about climate change, come to California,” Governor Gavin Newsom told the Democratic National Convention. “11,000 dry lightning strikes we had over a 72 hour period [led] to this unprecedented challenge with these wildfires.”

The New York Times NYT , CBS News, and other news outlets have reported that the wildfires destroyed a forest of ancient redwood trees in Big Basin state park.

“Hundreds of trees burned at Big Basin Redwoods State Park,” reported Shawn Hubler and Kellen Browning for The New York Times. “Park officials closed it on Wednesday, another casualty of the wildfires that have wracked the state with a vengeance that has grown more apocalyptic every year.”

“The protected trees, some 2,500 years old, were nearly wiped out by loggers in the 1800s,” claimed CBS News’ Jonathan Vigliotti. “Now human-caused climate change has damaged or destroyed many of these ancient giants.”

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“Big Basin Redwoods State Park has burned through,” reported New York Magazine’s David Wallace-Wells, pointing to climate change as the cause. “Some, older than Muhammad, had stood for a thousand years by the time Europeans set foot in North America. The youngest are older than the Black Death."

But every school child who has visited one of California’s redwood parks knows from reading the signs at the visitor’s center and in front of the trailheads that old-growth redwood forests need fire to survive and thrive.

Heat from fire is required for the release and germination of redwood seeds, and to burn up the woody debris on the forest floor. The thick bark on old-growth redwood trees provides evidence of many past fires.

And, indeed, video footage taken by two San Jose Mercury News reporters, who hiked into Big Basin after the fire, shows the vast majority of trees still standing. What was burned up was the visitor’s center and other park infrastructure.

Video footage shows the vast majority of trees in Big Basin are still standing.

Nor is it the case that California’s fires have “grown more apocalyptic every year,” as The New York Times reported. In fact, 2019 saw a remarkably small amount of acreage burn, just 280,000 acres compared to 1.3 million and 1.6 million in 2017 and 2018, respectively.

What about this year’s fires? “I see [the current California fires] as a normal event, just not one that happens every year,” Jon Keeley, a leading forest scientist, told me.

“On July 30, 2008, we had massive fires throughout northern California due to a series of lightning fires in the middle of the summer,” he said. “It’s not an annual event, but it’s not an unusual event.”

California’s fires should indeed serve as a warning to the public, but not that climate change is causing the apocalypse. Rather, it should serve as a warning that mainstream news reporters and California’s politicians cannot be trusted to tell the truth about climate change and fires.

The area that burns annually in California has declined over 80% since the arrival of Europeans, and . [+] that's not necessarily a good thing

It’s Not About The Climate

Nobody denies climate change is occurring and playing a role in warmer temperatures and heatwaves. Keeley notes that, since 1960, the variation in spring and summer temperatures explain 50% of the variation in fire frequency and intensity from one year to the next.

But the half-century since 1960 is the same period in which the U.S. government promoted, mostly out of ignorance, the suppression of regular fires which most forests need to allow for new growth.

For much of the 20th Century, U.S. agencies and private landowners suppressed fires as a matter of policy. The results were disastrous: the accumulation of wood fuel resulting in fires that burn so hot they sometimes kill the forest, turning it into shrubland.

The US government started to allow forests in national parks to burn more in the 1960s, and allowed a wider set of forests on public lands to burn starting in the 1990s.

“When I hear climate change discussed it’s suggested that it’s a major reason and it’s not,” Scott Stevens of the University of California, Berkeley, told me.

Redwood forests before Europeans arrived burned every 6 to 25 years. The evidence comes from fire scars on barks and the bases of massive ancient trees, hollowed out by fire, like the one depicted in The New York Times photograph.

“There was severe heat before the lightning that dried-out [wood] fuel,” noted Stevens. “But in Big Basin [redwood park], where fire burned every seven to ten years, there is a high-density of fuel build-up, especially in the forests.”

In 1904, three large fires burned Big Basin for 20 days, scorching the crowns of many trees, just as the 2020 fire did.

Reporters for The New York Times were apparently as pyrophobic 116 years ago as they are today, reporting that year that Big Basin, “seems doomed for destruction.”

But redwood forests regularly burn. A 2003 fire in Humboldt Redwoods State Park burned 13,774. Forest in 2008 burned over 165,000 acres. And a 2016 fire burned 130,000 acres.

Climate activists who in the winter excoriate those, like Senator James Inhofe, for pointing to snow as proof that global warming isn’t happening, turn around and point to summer fires as proof that it is.

“In my [five years] as a Californian,” wrote Leah Stokes in The Atlantic. “I’ve seen a years-long drought. I’ve evacuated my home as a wildfire closed in. I’ve lived through unprecedented heat waves…. that climate is no more.”

Environmental scholars scoff at this ahistorical view. “The idea that fire is somehow new,” said geographer Paul Robbins of the University of Wisconsin, “a product solely of climate change, and part of a moral crusade for the soul of the nation, borders on the insane.”

Fire Does Not A Hell Make

The amount of California that burns year to year is not uniform, Keeley emphasizes. “It was a mistake for the politicians in 2017 and 2018 to say ‘This is the new normal’ because 2019 was totally abnormal compared to 2017 and 2018.”

Is that amount abnormal? Not historically speaking. Scientists calculate that, before Europeans arrived, 4.4 million acres of California burned annually, which is 16 times larger than the amount that burned in 2019.

“Of the hundreds of persons who visit the Pacific slope of California every summer to see the mountains,” reported a U.S. government scientist in 1898, who had surveyed the region, “few see more than the immediate foreground and a haze of smoke.”

Even if 1.5 million acres of burned area per year indeed ends up being the “new normal” for a decade, it will still be one-third of the pre-industrial, pre-European average.

Why do activist journalists and politicians get California’s fires so wrong?

Part of the reason is their determination to blame climate change for everything.

“If all you have is a hammer everything looks like a nail,” noted Keeley. “If all you study is climate change than everything looks like it is caused by climate change. Every climate change research center finds climate is a problem. They are trying to find climate as the explanation.”

Climate bias is compounded by partisan bias. For example, journalists ridiculed President Donald Trump for suggesting that California’s fires were due to the state’s failure to remove undergrowth from its forests, even though scientists agree that the build-up of wood fuel through fire suppression is a massive problem.

Part of the problem is that many environmental journalists are so disconnected from the natural environment.

“I’m not an environmentalist,” confessed Wallace-Wells in his 2019 book, The Uninhabitable Earth, “and don’t even think of myself as a nature person. I’ve lived my whole life in cities. I’ve never gone camping, not willingly anyway…”

But if Wallace-Wells had been more of a “nature person” he might have known that fires are part of the cycle of life for redwood and many other forests.

The New York Times and other news media published a photo of a large, ancient redwood tree whose inner trunk is on fire. Many readers might have reasonably assumed the tree was dead, but that’s not necessarily the case.

In 1911, a reporter for the Santa Cruz Sentinel stood inside one of the trees hollowed out by the 1904 fire and noticed that it was still growing.

“To stand in the trunk of this tree and look up through the charred interior to the patch of blue sky far above, interlaced there with green branches, emphasizes the work of nature when producing the strange and awe-inspiring.”

The picture that Wallace-Wells and other activist journalists paint has more to do with religious depictions of a burning underworld than scientific descriptions of burning underbrush. “Looking from the vantage of today,” Wallace-Wells said last year, “we see that world and can think of it basically as a hell.”

Facts seem unlikely to get in the way of his desire to tell a good story. “Fires are among the best and more horrifying propagandists for climate change,” he notes, “terrifying and immediate, no matter how far from a fire zone you live.”

Forest Thinning Effects on Fire

Figure 1 Fire in unthinned forest. © Erica Simek Sloniker

Figure 2 Fire in forest that has been thinned. © Erica Simek Sloniker

Montana Forest Thinning Crews thinning Montana forests to reduce wildfire risks and help forests thrive. © Mike Schaedel/TNC

Fire Smart Canada – helps people understand the potential of wildland fire affecting homes and communities. It includes a risk reduction program for forestry companies.

Forest Change Toolkit – a list of tools and resources for climate change adaptation

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Richards, F. J. A flexible growth function for empirical use. J. Exp. Bot. 10, 290–301 (1959).

Kuhn, M. et al. Caret: 6.0-71., Classification and Regression Training. R package version. (2016).

R Development Core Team. R: A Language and Environment for Statistical Computing. (2020).

Strobl, C., Boulesteix, A. L., Zeileis, A. & Hothorn, T. Bias in random forest variable importance measures: Illustrations, sources and a solution. BMC Bioinformatics 8, 25 (2007).

Strobl, C., Boulesteix, A. L., Kneib, T., Augustin, T. & Zeileis, A. Conditional variable importance for random forests. BMC Bioinformatics 9, 1–11 (2008).

Strobl, C., Hothorn, T. & Zeileis, A. Party on! A new, conditional variable importance measure available in the party package. R J. 1, 14–17 (2009).

Behnamian, A. et al. A systematic approach for variable selection with random forests: achieving stable variable importance values. IEEE Geosci. Remote Sens. Lett. 14, 1988–1992 (2017).

Congalton Russell, G. & Green, K. Assessing the Accuracy of Remotely Sensed Data: Principles and Practices. vol. 25 (CRC Press, 2009).

Heinrich, V. et al. Data from paper: Large carbon sink potential of Secondary Forests in Brazilian Amazon to mitigate climate change. Zenodo (2021).

Heinrich, V. et al. Code from paper: Large carbon sink potential of Secondary Forests in the Brazilian Amazon to mitigate climate change. GitHub (2021).

Breathing Fire: Fighting fire with fire: Should California burn its forests to protect against catastrophe?

By Maya Miller (Climate Central), Ryan Sabalow (The Sacramento Bee) and Dale Kasler (The Sacramento Bee)

This story was produced through a partnership between Climate Central and the The Sacramento Bee.

It seemed like a good day for a fire &mdash the kind that could safely thin out an overgrown forest, eliminate combustible underbrush and reduce the risk from an out-of-control wildfire like the ones that have devastated California communities in recent years.

This story is part of Breathing Fire, an ongoing Climate Central series of research briefs and journalism projects dealing with wildfires and their causes, impacts, and solutions.

But when a lightning strike ignited a small fire May 10 in the Tahoe National Forest, on a relatively cool day in an area still green from winter rains, federal firefighters did what they almost always do: They raced to snuff it out. The Sugar Fire in the foothills east of Sacramento was fully contained within two days, before it could spread beyond 65 acres.

Seven months after the Camp Fire killed 85 people and destroyed much of Paradise, and with another potentially catastrophic wildfire season getting underway, a growing body of experts say California is neglecting a major tool in its battle against mega-fires: the practice of fighting fire with fire.

The June 7, 2019 KQED story "Town Unites Against Federal Mismanagement to Save Forest," cites Climate Central's data analysis.

These experts say state and federal firefighting agencies should allow more fires that don&rsquot threaten the public to run their natural course. What&rsquos more, they say fire agencies should conduct more &ldquoprescribed&rdquo burns &mdash fires that are deliberately set, under carefully controlled conditions, to reduce the fuels that can feed a disaster.

&ldquoNothing affects fire like fire,&rdquo said Timothy Ingalsbee, executive director of Firefighters United for Safety, Ethics & Ecology in Eugene, Ore. &ldquoIf we don&rsquot start applying a lot more fire now, while conditions are still somewhat amenable to fire control, years ahead &mdash given climate change &mdash it&rsquos just going to be really an untenable situation.&rdquo

The Sugar Fire this month, an unplanned fire that ignited soon after a wet winter, was &ldquodoing good ecological work for free,&rdquo said Ingalsbee, a former firefighter with the U.S. Forest Service and National Park Service. &ldquoLater on, they&rsquoll have to put another fire out at big expense.&rdquo

KQED interviews Climate Central science reporter Maya Miller

In California, the debate over prescribed burns is complicated by a deadly history with wildfires that have grown quickly out of control, the state&rsquos stringent environmental regulations, fear of liability lawsuits and infringement on property rights, and the huge swaths of federal forestland with their own management rules and oversight.

Added to the mix is antagonism between California officials and President Donald Trump, who claimed there was &ldquono reason&rdquo for costly and deadly wildfires here, &ldquoexcept that forest management is so poor.&rdquo Trump has repeatedly threatened to cut off federal fire assistance to the state, failing to acknowledge that his own administration manages more than half the forests in California.

Most recently, the Forest Service said it was cutting millions in aid for California fire departments, accusing the state of over-billing the feds under a contract agreement.

For their part, the Tahoe National Forest&rsquos managers say they understand the ecological value of allowing fires such as the Sugar to burn when conditions are safe. But while the agency has loosened the rules on letting fires burn on some national forests, managers of the Tahoe are still required to extinguish any fire that ignites in the woods as quickly as possible.

That may soon change. Tahoe forest officials are beginning the process of updating their quarter-century-old management policy to give fire managers, such as Shelly Allen, more discretion to allow fires to burn if there&rsquos little risk to people, infrastructure or private property.

Last week, standing in boots on charred pine and fir needles the Sugar Fire scorched, Allen said that if the updated policy had been in place the Sugar Fire would likely have been allowed to burn a larger area. Although the fire burned near a reservoir that had to be protected, the fire could have burned longer in the opposite direction without doing any harm.

&ldquoSo it (would do) this natural thinning process that we&rsquore trying to do with our prescribed fires,&rdquo Allen said. &ldquoThese fires come in and they really clean up our ground fuels, so when a fire comes in here next time, you&rsquore going to have less of an impact.&rdquo

Shelly Allen, a fire management officer for the U.S. Forest Service, tours a 65-acre area on Friday, May 24, 2019, that was burned in May after a lightning strike started the Sugar Fire in the Tahoe National Forest. Paul Kitagaki Jr. ([email protected])


Data collected by McClatchy and Climate Central, a nonprofit research and news organization based in New Jersey, show that California is barely making a dent in using fire to reduce the staggering amounts of fuels choking the state&rsquos forests.

By some estimates, many of the state&rsquos forests have up to 100 times the amount of small trees and underbrush than what grew prior to white settlement. Meanwhile, researchers estimate that prior to 1800, some 4.5 million acres of the state&rsquos forests burned in a typical year &mdash more than the 1.9 million acres that burned in 2018, the most in modern history.

Yet in a state with more than 30 million acres of forest, only about 87,000 acres of California land were treated with prescribed burns last year to reduce undergrowth prior to the state&rsquos deadly fire season, according to data from Cal Fire, the U.S. Forest Service and the U.S. Bureau of Land Management.

Prescribed fire treats far more land in other parts of the country. In Florida, more than 2 million acres was subjected to prescribed burns in 2017, the last year for which data was available, according to Climate Central. Over the past 20 years, the Southeast has been responsible for 70 percent of the acres in the United States with prescribed burns, according to just-published research in the academic journal Fire.

&ldquoThe Southeast has figured out a way to get a lot of fire on the ground,&rdquo said Crystal Kolden, a specialist at the University of Idaho who authored the study published in Fire. &ldquoThe key thing the West can learn is that this has to be a process that has to have a lot of community engagement and buy-in. It has to be a collaborative effort with the citizens of the regions who understand that doing a prescribed fire can help prevent Paradise-like devastation and destruction.&rdquo

But federal officials in California, who manage more than half of the state&rsquos forested lands, say California has a number of challenges that aren&rsquot present in the Southeast.

The federal and state agencies responsible for prescribed burns find themselves hemmed in by California&rsquos tinder-dry Mediterranean summer and fall months, strict air quality rules, rugged terrain, and a checkerboard pattern of landownership that often puts private property uncomfortably close to public lands.

&ldquoGiven the parameters in California, the complexity of having 39 million people in the state, (we&rsquore doing) a lot of burning, a lot of prescribed burning,&rdquo said Stanton Florea, a spokesman for the Forest Service.

There&rsquos also a long-standing, deep-seated fear of fire in the heavily wooded West that can make agencies think twice before starting a deliberate fire or letting a natural fire run its course. It&rsquos a philosophy that&rsquos been around for about a century, when the federal government adopted a strict practice of suppressing fires as quickly as possible, and has only begun to loosen in the past couple of decades.

&ldquoIt&rsquos just the culture around fire in the West. We really have a fire-suppression culture,&rdquo said Lenya Quinn-Davidson, a UC Cooperative Extension forestry expert and director of the Northern California Prescribed Fire Council. &ldquoThere is widespread recognition that we are not doing enough in the West.&rdquo

State and federal officials in California, however, say they&rsquore making strides in reducing what they call the &ldquofire deficit&rdquo by conducting more prescribed burns than in years past. The Forest Service&rsquos Florea said the agency deliberately burned almost 63,000 acres of California land in the 2017-18 fiscal year &mdash the most ever, and a 40 percent increase from the year before. Cal Fire burned more than 19,000 acres in the 2017-18 fiscal year, a 50 percent increase from the year before.

&ldquoIt&rsquos ramped up it&rsquos five times the pace we were doing before,&rdquo said Len Nielson, a Cal Fire fuels crew supervisor.

State leaders are pushing for more. In SB 901, signed last year by former Gov. Jerry Brown, the Legislature earmarked $175 million over five years for additional prescribed burns on state and privately owned lands. Nielson said Gov. Gavin Newsom&rsquos proposed budget would fund four new Cal Fire &ldquofuels crews,&rdquo which would thin forested lands with a combination of chainsaws and prescribed fires. Cal Fire currently has six of those crews, he said.

But cutting through the red tape to carry out a prescribed fire can be tedious and time-consuming.

In some national forests, the undergrowth has grown so thick, fire managers need to hire contractors to go in first and cut and haul away the dense brush and small trees before they light the match. If they don&rsquot, they say, a burn could climb from the tall underbrush to the tops of the big, hardy trees the foresters want to survive.

That sort of pre-thinning requires its own regulatory approval, a process that can take years. Foresters then need to create a &ldquoburn plan,&rdquo which can take up to two years before it&rsquos approved, officials say.

&ldquoSometimes from start of the project to final implementation, it can take 15 years,&rdquo said Brian Crawford, a fuels technician with the Tahoe National Forest. &ldquoIn some people&rsquos career, they barely see the start to the finish. We should be putting fire in these ecosystems at a greater rate than that.&rdquo

Prescribed burns remain controversial among some environmentalists, who aren&rsquot afraid to file a legal challenge to kill a burn in court.

Brian Crawford of the U.S. Forest Service shows map of a 427-acre prescribed burn in the Foresthill area to help fire suppression on Friday, May 24, 2019 in the Tahoe National Forest. Paul Kitagaki Jr. ([email protected])

The Chaparral Institute, an environmental group in Escondido, said deliberately setting fires to chaparral can leave the lowland forests in worse shape than before, as the grasses are typically replaced by non-native weeds that are more combustible.

As fuels for wildfires have built up in forests, the effects of climate change have also increased the risk of wildfires. Rising temperatures are causing snowpack to melt earlier and drying out landscapes at a faster rate. In the past two decades, climate change caused twice as much Western forestland to burn in wildfires, compared with what would otherwise have been expected, University of Idaho and Columbia University researchers have concluded.

&ldquoYou&rsquove got a more flammable, ignitable environment,&rdquo said the institute&rsquos Richard Halsey.


Air quality is one of the biggest barriers to prescribed fire in California, which has the strictest pollution standards in the nation.

The California Air Resources Board or one of the big regional air-pollution agencies, such as the San Joaquin Valley Air Pollution Control District, must agree to let the firefighting agency conduct a burn on a particular plot of land. Then the local air district or fire marshal gives the final approval, sometimes just hours before the burn is scheduled to begin.

&ldquoIt&rsquos challenging to work through the permitting process,&rdquo said Quinn-Davidson, the UC forestry specialist.

She said the air districts have limits on how much air pollution they&rsquoll allow in a given area on a given day. As a result, &ldquoprescribed burning is competing with industry, or automobile emissions, for the same air space,&rdquo she said.

In some ways, she said, the firefighters and air-quality regulators are working at cross purposes. Air regulators prefer the burns to occur on fairly windy days, so the smoke will blow away from the population. But firefighters want to set fires when winds are calm &ldquobecause it helps us keep things under control,&rdquo she said.

Planning a burn means gauging wind patterns, humidity, vegetation types and other factors. Last-minute changes in the weather can force cancellations of scheduled burns that have taken years of study and the planning.

&ldquoYou&rsquove got everything lined up, you&rsquove got your people lined up and you&rsquore ready to go and then you don&rsquot get the green light,&rdquo said Jim Branham, recently-retired chief of the Sierra Nevada Conservancy, a state agency that promotes forestry management projects.

State officials say the relationship between air regulators and firefighters is improving. &ldquoWe work collaboratively now, way more than we did five or 10 years ago,&rdquo said Nielson. In an action plan issued in February, Cal Fire pledged to work with state and federal environmental agencies &ldquoto increase the scale of prescribed burns while protecting air quality.&rdquo

John DaMassa, chief of modeling and meteorology at the Air Resources Board, said his agency is committed to allowing more prescribed burns.

&ldquoWe&rsquore a public health agency we recognize that prescribed fire produces smoke,&rdquo he said. &ldquoBut we believe it&rsquos much more palatable compared to the extreme fire events we&rsquove seen recently.&rdquo


Further complicating matters is how land is divvied up in and around much of California&rsquos forested regions.

Joe Flannery, a spokesman for the Tahoe National Forest, said much of the forest is carved into a checkerboard of public land interspersed with private property, including homesteads and the holdings of big lumber companies such as Sierra Pacific Industries. Unless private owners agree to burn their lands as well, that makes it difficult to conduct prescribed fires across a vast landscape. And a prescribed fire burning on public property could easily jump to land in private hands, creating legal and financial headaches.

The risk of something going haywire is far from theoretical.

Brian Crawford of the U.S. Forest Service walks on fire barrier between the prescribed burn on Tahoe National Forest land and private property in Foresthill area on Friday, May 24, 2019. Paul Kitagaki Jr. ([email protected])

In July 1999, a fire set outside of Redding by the U.S. Bureau of Land Management, intended to eliminate 100 acres of noxious weeds called the star thistle, quickly exploded into a 2,000-acre fire that destroyed 23 homes over five days. The agency&rsquos post-mortem report on the Lowden Ranch Fire concluded that &ldquoan unqualified person prepared the burn plan&rdquo and failed to recognize the &ldquoextreme fire danger conditions&rdquo that existed when the fire was lit.

One of the nation&rsquos worst &ldquocontrolled&rdquo burns that wasn&rsquot came a year later, when a prescribed fire in the Bandelier National Monument in New Mexico escaped containment. The fire burned 75 square miles, destroyed more than 200 homes and damaged the legendary Los Alamos nuclear weapons laboratory.

Blasting the planning behind the fire as badly flawed, then-Interior Secretary Bruce Babbitt and Agriculture Secretary Dan Glickman ordered a 30-day suspension of all prescribed fires in the western half of the United States so a stricter approval process could be implemented.

Prescribed fire planning and implementation has improved since then, advocates say, but they acknowledge there&rsquos no way to completely reduce the risks. (It&rsquos why foresters don&rsquot use the term &ldquocontrolled burn&rdquo anymore). Some fire managers worry so much about being sued from an escaped burn they buy personal liability insurance.

Last month, while standing at the site of a 2018 prescribed fire she approved outside Missoula, Mont., Jennifer Hensiek, a district ranger in the Lolo National Forest, said she bought an insurance plan when she started approving prescribed fire plans about seven years earlier.

She said she needed the extra protection. After all, she signs her name to the bottom of a lengthy document that spells out every risk and contingency, prior to anyone lighting a flame torch &mdash and that makes her a target for a savvy civil attorney if the fire jumped its lines and burned someone&rsquos home.

&ldquoHow people would interpret negligence or not, that&rsquos the piece that concerns me,&rdquo she said.

&lsquoA BIG SHIFT&rsquo

Natural wildfire was long a part of California&rsquos history. The millions of acres that once burned every year before white settlement &mdash either set by lightning strikes or intentionally ignited by Native Americans as a land-management tool &mdash rid the forests of excess brush and small trees while enhancing the soils, spurring healthier eco-systems and improving the habitat for the game on which the native peoples relied.

But a series of massive wildfires in the West in the late 1800s and early 1900s ushered in an Little Hoover Commission said in a 2018 report.

This approach didn&rsquot begin to change until the 1960s, though states in the Southeast had been utilizing the practice against the Forest Service&rsquos orders for decades. Inspired in part by Harold Biswell, a forestry expert at UC Berkeley and Davis, fire agencies became more willing to let natural fires burn and conduct prescribed fires.&rdquo

A vehicle drives by down Foresthill Road on Friday, May 24, 2019, passing a sign that warns the U.S. Forest Service has performed a prescribed burn in the area to help fire suppression in the Tahoe National Forest. Paul Kitagaki Jr. ([email protected])

Change comes slowly, though. Ingalsbee, of the firefighters&rsquo group in Oregon, said the Forest Service maintains a no-tolerance policy in several of its national forests when a fire breaks out naturally.

He said the strategy is known as the &ldquo10 a.m. policy,&rdquo meaning the goal is to extinguish a new fire by the next morning. &ldquoIt&rsquos not legacy,&rdquo he said. &ldquoIt&rsquos the current reality.&rdquo

The Forest Service disputes that. Bob Baird, regional director of fire and aviation management, said his agency has become far more flexible about allowing naturally occurring fires to burn when there&rsquos &ldquoa low risk to the public or watersheds or smoke impacts.&rdquo He said the agency wants to &ldquominimize destructive wildfire and create healthy fire.&rdquo

In 2015 the Forest Service and Cal Fire signed a landmark memorandum of understanding in which each pledged to &ldquosupport the expanded use of fire to improve ecological conditions and more effectively undertake fire management across the landscape.&rdquo The document was also signed by several environmental groups, such as the Sierra Club and the Nature Conservancy about a year later, the agencies that regulate air pollution in Placer, El Dorado and Butte counties also signed it.

Although the memo is nonbinding, experts such as Quinn-Davidson see the document as a transformation in how agencies such as the Forest Service view prescribed burns.

&ldquoHistorically they did not want to see more fire on the ground,&rdquo she said. &ldquoI think we&rsquore seeing a big shift. People are ready to embrace it, and use this tool.&rdquo

The managers of the Tahoe National Forest hope to use fire more than they do. Last year, the forest used fire to treat just 5,581 of its 850,000 acres. Tahoe forest officials said they&rsquod eventually like to see managed fire on at least 10 percent of the woods each year. But, for now, they&rsquore chipping away.

The signs telling the public not to call 911 still stood last week on the busy road outside Foresthill where earlier this month crews burned about 427 acres along the roadway &mdash just a couple of miles from where the lightning bolt started the Sugar Fire.

Crawford, the fuels technician for the Tahoe National Forest, said the local residents and the regional air quality officials have embraced fire too, and were quick to throw their support behind the burn.

&ldquoThey understand the pros of us getting fire on the ground during spring and fall conditions where it&rsquos in our favor far outweigh a fire in the summer,&rdquo he said.

Maya Miller is a reporter with Climate Central. McClatchy&rsquos reporting was supported by the Institute for Journalism & Natural Resources.

One contribution of 24 to a discussion meeting issue ‘The interaction of fire and mankind’.

Published by the Royal Society. All rights reserved.


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