Busier Season for Prescribed Burns Should Mean Less-Busy Wildfire Seasons
Pisgah National Forest is ramping up its controlled burn program to restore natural landscapes and limit the spread of potentially destructive wildfires.
PISGAH NATIONAL FOREST — If its source had been a wildfire, the blue-gray column of smoke that Helen Mohr pointed out from a Blue Ridge Parkway overlook Tuesday might have been described as “alarming.”
“Ominous,” could have fit or, considering the mounting devastation of out-of-control blazes across the warming globe, so could, even, “terrifying.”
But because Mohr was looking at the product of a prescribed burn, she was able to speak in the calm, appreciative terms of a connoisseur.
“We’ve been watching it all day and it kind of started as a little bit of a blob,” she said. As the fire built heat and momentum, its smoke began to rise straight and fast, said Mohr, Pisgah National Forest’s Restoration Initiative Coordinator, and “that is a really beautiful smoke plume right there in front of us.”
In fact, she could point to three pillars of smoke clearly visible against the otherwise flawless blue sky.
The column on her far right came from a prescribed fire on federal land west of Lake Jocassee. The handsome, rave-inspiring plume in the center rose from a burn at DuPont State Recreational Forest. A growing cloud a few miles to her left emerged from the fire she was monitoring, which would spread across 1,300 acres of Pisgah anchored by Pilot Mountain.
As all this activity indicated, last Tuesday was an ideal day for controlled burns — clear, light breeze, soil moistened by recent rains, branches still bare of fire-vulnerable leaves and buds. Because such conditions are common this time of year, late winter is the busiest burn season.
And thanks to the initiative that Mohr is coordinating — and that includes plans for about 15,000 acres of prescribed fire in the Forest annually — it’s getting far busier.
As it should, fire researchers say.
A restored forest is not only a healthier forest, more welcoming of oaks and other species crucial to supporting wildlife. It is also more resistant to wildfires such as the ones that consumed about 74,000 acres in North Carolina last fall, blazes that are likely to grow far more common and severe with climate change.
By the end of the century, wildfires could consume three times as much federal land annually as they typically do now, according to a 2022 US Forest Service study.
Controlled burns can’t eliminate this threat, but they are one of the Service’s best tools to contain it, which leaves the public with a choice.
It’s a choice between beneficial fire set intentionally in ideal conditions and the opportunistic, out-of-control variety that destroys stands of timber, homes and even large swaths of medium-sized cities.
And it is a choice illustrated by columns of smoke that on Tuesday not only rose rapidly, but dissipated in the breeze far above Brevard.
“If this was a wildfire, we might be dealing with smoke on the fire’s terms for 30 days,” Mohr said. “When we can do a prescribed burn, we’re dealing with smoke on our own terms.”
Targeting Favorite Plants
Just as foresters have an expert appreciation of smoke, their take on widely beloved plant species is informed by the history of forest fires.
Data harvested from the rings of ancient trees shows Southern Appalachian forests formerly burned about once every decade, Mohr said. Moist, low-lying forests burned less often than that, and higher ground — especially sunny, south-facing slopes — more frequently.
The Forest Service’s long-standing policy of aggressively fighting all wildfires — still necessary in natural land near developed areas — allowed the spread of fire-vulnerable vegetation from its natural creekside environment towards mountain ridges.
Those plants include flowering mountain laurels and rhododendron, towering tulip poplars, red maples with their distinctive burgundy blossoms. These are the targets of burns, often spoken of as enemies of healthy forests — not because they don’t have their place, but because, depending on the species, their upward advance can either crowd out fire-adapted oaks and pines or fuel damaging wildfire.
“A lot of times to describe our forests, we say they are a little bit out of whack,” Mohr said.
The cones of the scrubby table mountain pine, a hallmark of Appalachian ridge tops, need intense heat and light to open, which means the tree needs fire for a fighting chance to hold its ground. Shortleaf pine, which is adapted to sprout from burned stumps, “is another species that thrives very well with fire,” Mohr said.
Most oaks are also fire-resistant, and containing the spread of maples, poplars and mid-story shrubs opens up ground to allow their acorns to sprout and to ultimately produce many more acorns — a major component of the annual supply of nuts and fruit known as “mast.”
“Mast is a huge thing,” Mohr said. “Our mast crop supports our large mammals, our bear and our deer.”
Mountain laurels, meanwhile, are “highly flammable,” she said, and act as a “ladder fuel” along with rhododendrons, a robust stand of which flanked not only the overlook’s parking lot but an adjacent stand of conifers.
“That’s a good visual of a ladder fuel right there,” she said. “It could easily spark the taller trees. It’s kind of a ladder putting fire into the overstory.”
Repeating Fire History
At Gloucester Gap, on the eastern edge of Tuesday’s burn zone, Forest Service workers stood on guard as a line of ground-hugging flames moved slowly through dead leaves towards a gravel road that served as a built-in fire break.
This “black-lining” fire, ignited by handheld drip torches, created a charred buffer between the road and the soon-to-be advancing main fire, which had been set by a crew in a helicopter dropping chemical-filled plastic balls that ignited on impact.
“We make the fire line wider, so when the (main) fire hits there’s no more fuel left to burn,” Mohr said of the black line. “It’s a safeguard.”
Meanwhile, in the core of the 1,300-acre “burn unit,” the fire did what intermittent blazes used to do — move with significant speed and heat at high elevations, including the top of Pilot Mountain, where bursts of flame could clearly be seen from the Parkway, Mohr said.
Ignition slowed or fizzled out altogether, on the other hand, as it hit the banks of the several small streams in the unit, meaning thriving stands of those cherished, fire-sensitive shrubs and trees would emerge from this burn just fine — as long as they grew in their natural territory.
“That’s exactly how a fire would have burned across the landscape historically, with native people burning and with lightning,” she said of the prescribed fire.
Is More Burning Enough Burning?
There’s no doubt that such burns can impede potentially destructive wildfires, and Mohr pointed to a dramatic example of just such an occurrence east of Asheville, in Pisgah’s Grandfather Ranger District.
In June of 2015, a lightning strike ignited a fire there during drought conditions and in remote, mountainous terrain that hampered the work of fire crews, according to a Forest Service report on the blaze. But when flames encountered the “Lake James prescribed burn area, treated most recently in January 2015,” the report said, the fire was held “from any spread east of the ridge top.”
But can controlled burns be conducted widely enough and often enough to contain wildfires such as those that, the following year, consumed a total of 231 square miles in the southern Appalachians and killed 14 people in communities near Great Smoky Mountains National Park?
Robert Scheller, a professor of Forestry and Environmental Resources at North Carolina State University, has called 2016 a “watermark year for wildfire,” a reminder that the Southeast is vulnerable to the kind of devastating blazes usually associated with the West.
It’s also a likely preview of the future, according to a study he co-authored that predicted that at the end of the century nearly one-third more land in the Southern Appalachians will burn in the average fire year than in 2016.
Extensive controlled burning in this region, he said, is hampered by mountainous terrain, the small size of its natural areas compared to those in the West, and the crowding of development in the so-called wild-urban interface, or WUI (WOO-ee).
“In order for any prescribed fire to be effective against wildfire, it has to be done on a pretty large scale and pretty frequently,” Scheller said last week.
“Is it realistic that we can ever scale up prescribed burning to substantially reduce wildfire?” he asked rhetorically. “That’s a good question.”
The Rebirth of Forests
It’s a question the Forest Service can begin to answer in Pisgah with the work of the Collaborative Forest Landscape Restoration Program (CFLRP).
The Program, previously established in the Grandfather Ranger District, was extended to the Forest’s two other districts starting last year, and will make about $1 million available annually for burns and other restoration work — including the control of invasive plants — over a 10-year period.
The goal of the initiative is to expand the area treated by fire in the Forest from about 4,000 acres annually to between 10,000 and 18,000 acres. It’s on track to hit that target this year, with planned burns covering nearly 16,000 acres.
Even at that rate, prescribed burns will fall well short of replicating historic fire frequency in Pisgah, which covers a total of about 500,000 acres. But it still means a far larger area of the Forest will not only be less susceptible to damaging wildfires, but returned to a more vibrant historic form.
On recently burned land along US 276, north of the Pisgah Ranger Station, faint charring can still be seen on fallen tree trunks. The once tall and extensive coverage of mountain laurels and rhododendrons has been reduced to a leafless vestige, replaced by ankle-high shrubs.
These are no longer a threat to boost fire into treetops. They will no longer shade out native ferns and wildflowers, which are expected to blanket the forest floor as spring advances.
“The reason is, we’ve opened up that forest with fire and we’re letting in more sunlight,” Mohr said of this fire-exposed land. “We’ll see bursts of lots of different species that we wouldn’t see in a closed canopy.”
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A very informative article. Thank you so much
Nice to have an explanation to understand the purpose. Thanks Dan.