The smoke in Arizona's high country could be a prescribed burn. Here's what to know

If you see smoke in Arizona’s high country this fall, it’s probably a fire. But it’s just as probable that it’s not a wildfire sweeping through the forest, but part of a prescribed burn managed by the U.S. Forest Service.

As the monsoon ends and temperatures cool, the Forest Service oversees prescribed burns through overgrown areas in national forests, partly as a way to prevent wildfires. The burns protect communities and critical infrastructure from wildfires while promoting healthy and resilient forests.

Here’s what to know about prescribed burns this fall:

What is a prescribed burn?

While Arizona has had plenty of destructive wildfires over the years, fires in the forests aren’t always bad news. Prescribed burns, also known as prescribed fires or controlled burns, are planned fires by forest officials, meant to do the work natural fire once did.

“Before we had land management agencies doing prescribed fire, we had lightning-sparked wildfires,” said Randi Shaffer, a public affairs officer for the Coconino National Forest. “So fire is a very natural part of our landscape here in Arizona.”

Officials intentionally light and manage these fires to reduce hazardous vegetation that fuels wildfires, recycle nutrients into the soil, clear unwanted or invasive plant species in the ecosystem and support growth for desired trees, wildflowers and plants.

Low-intensity fires promote a healthy ecosystem in Arizona’s forests. Plants have adapted to natural fires, and burned areas tend to regrow more quickly and healthier, especially from nutrient-rich ash that acts as a fertilizer.

Suppressing all fires can hinder an ecosystem, causing overcrowding, disease, pest infestations, a decline in fire-dependent plants and a build-up of fuels.

The Forest Service typically plans prescribed burns five to 10 years in advance to locate which areas need treatment. Officials create a burn plan, which helps identify the ideal conditions for a prescribed burn to get the desired results safely.

“We have to wait for what we call a window, and that window is usually very narrow. All the stars have to align,” Shaffer said. “We need the right temperatures and humidity, adequate staffing, the right wind direction and wind speeds and fuel conditions.”

Officials consider the moisture of the vegetation and the dispersal of smoke when creating a burn plan. The fuel cannot be too wet or too dry to burn properly.

On the scheduled burn day, officials compare live conditions to those set in the burn plan before moving forward with a prescribed burn. If those conditions aren’t met, they postpone the burn.

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Where are the prescribed burns?

Visitors seeking fall colors throughout the high country should be aware of potential smoke and closures, especially around Coconino and Apache-Sitgreaves national forests.

The Forest Service announced it began several prescribed fire projects around the Coconino National Forest starting Monday and will continue through Oct. 25 if weather and fuel conditions allow. They will ignite fires near Stoneman Lake and north of Bellemont. Officials expect interruptions and smoke exposure will be minimal.

The Apache-Sitgreaves National Forest is burning potential fire fuels north of Show Low within the Redhead Marsh area between Oct. 10 and Oct. 20. This week, officials will manage fires in Fulton, Whiting and Wallow, covering 8,757 acres.

Officials are also planning prescribed burns in Coronado National Forest and will begin operations on Oct. 20. They plan to burn about 500 acres by Mount Lemmon and Mount Bigelow near Summerhaven.

Prescribed fire season also started in Prescott and Kaibab National Forests earlier this month. Operations in Prescott National Forest began on Oct. 2 and will continue throughout the season in Groom, Ponderosa Park and Indian Creek, totaling over 3,000 acres.

Prescribed fire projects are ongoing in the Kaibab National Forest. Fire managers completed treatment through 3,635 acres in Kendrick and will continue burns across 3,500 acres in Blue Stem southeast of Tusayan. They are planning burns in Three Sisters north of Williams and Pine Flat Rock south of Williams when the weather allows.

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How do prescribed burns prevent destructive wildfires?

While it may seem counterintuitive to light fires when trying to prevent them, controlled burns are highly beneficial. Prescribed fires are part of the Forest Service’s 10-year strategy to prevent wildfires in areas most at risk, especially near communities.

Prescribed burns remove wilted grass, fallen branches, dead trees and expansive undergrowth. These fuels allow wildfires to burn hotter, spread wider and faster and last longer, which makes them very difficult and dangerous for officials to combat.

“All this dead matter accumulates on the forest floor, and it’s not going anywhere unless we burn it,” Shaffer said.

Burns also create buffer zones between homes, businesses, farms and infrastructure and the forests at risk for wildfires, also known as the wildland-urban interface. If a wildfire occurs, it will likely burn out when it runs out of fuel before reaching communities.

Are prescribed burns dangerous?

It can be alarming to see smoke in the distance, but prescribed burns are strictly regulated and rarely dangerous. According to the Forest Service, 99.84% of prescribed burns go according to plan.

While wildfires can jeopardize water supplies, prescribed burns pose little risk to water quality.

The Forest Service aims to produce light to moderate smoke during prescribed burns, and issue advisories if there is an air quality risk. Smoke is an unavoidable outcome of prescribed burns, but levels are significantly less than the widespread wildfires these burns prevent.

“If someone sees smoke, we ask that they consult our prescribed fire project plans before calling dispatch,” Shaffer said. “It’s really important to us because we do still have wildfires this time of year, and our dispatch line needs to remain open for emergency calls.”

To check where officials have approved active prescribed burns, visit smoke.azdeq.gov. This resource is updated daily with information for all active burns in the state.

Hayleigh Evans covers environmental issues for The Arizona Republic and azcentral. Send tips or questions to hayleigh.evans@arizonarepublic.com.

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This article originally appeared on Arizona Republic: Smoke in Arizona's national forests is probably from a prescribed burn