Orange flames crackle and quickly burn bright green and yellow grass to blackened ash. Smoke drifts through the long-leaf pine trunks. On the edges of the fire, wildland fire experts in green cargo pants and yellow shirts watch, observing the fire and collecting data.
It’s a routine prescribed burn March 3 on Fort Stewart, something that happens almost daily from Dec.1 to June 30. But the people watching the prescribed burn aren’t just from the installation’s Directorate of Public Works Forestry Branch. Meteorologists, climatologists, ecologists, and fire behavior and smoke analysts from the U.S. Forest Service, the U.S. Geological Survey, the National Weather Service, University of Florida and University of Washington are observing the burn, too.
Watching prescribed burns is all in a day out of the office for Joe O’Brien, a project leader with the U.S. Forest Service. He and his team came to Fort Stewart to observe how the installation prescribe burns its forests so data can be collected to help other installations and wildlands apply fire properly by creating next generation fire models—virtual burns that show prescribed fire managers how fire acts in different scenarios.
The data collection is the final phase of a multi-year Department of Defense project to study prescribed burns on Fort Stewart.
The bottom line of the study is to show the importance of prescribed burning. Prescribed burns keep southeastern forests healthy, O’Brien said.
“These forests require fire,” he said. “They require fire like the forest requires sunlight and soil.”
Annually, Fort Stewart prescribe burns 100,000 to 120,000 acres, with a daily average of 600 acres during the burn season. While the primary reason the installation burns is to provide open and safe training space for 3rd Infantry Division Soldiers, there are secondary benefits for the long leaf pines, red cockaded woodpeckers, gopher tortoise indigo snakes and other plants and animals that call the forest home.
“If you don’t burn these forests, you lose all the species that depend on this kind of forests,” O’Brien said.
Burning the forests correctly and conserving the flora and fauna calls for a prescription. Writing a prescription takes in to account several factors, O’Brien said.
“You’re thinking about wind speed, you’re thinking about wind direction,” he said. “You think about what’s called fuel moisture. You know how moist the fuel is, how ignitable it is, because you want to contain it the intention is to contain it within the boundaries. So the objective is to contain the fire in the boundary. So you know, if the wind’s too high or the relative humidity is too low, or it’s this kind of fuel that’s very flammable, you need to be more careful. But the professionals that do this day in day out, what we’re trying to do is provide them additional scientific support so they can fine tune their management so we don’t lose fires or we don’t put smoke in the wrong place.”
The southeast is one of a few regions of the United States where prescribed burns happen routinely. Fort Stewart has one of the biggest burn programs in the nation, allowing access to several opportunities to study fire, O’Brien said.
“The southeastern United States burns over a billion acres a year on purpose,” he said.
That much burning keeps wildfires out of the news for this part of the country, O’Brien said.
“We do have areas of the southeast that are prone to catastrophic wildfires,” he said. “But a big part of why you don’t hear about it a lot is because of the work people do with prescribed fire in the southeast. It kind of mitigates the threat for wildfire. So, you know, you do hear about big wildfires going on in places, like the Okefenokee.”
The research at Fort Stewart could have benefits for wildland fire management out west, especially with fuel management, the vegetation that drives fires, said Matt Dickinson, research ecologist with the U.S. Forest Service Northern Research Station, in Delaware, Ohio.
“There’s a lot of really basic research going on developing modeling tools and ways of mapping fuels…and getting better weather forecasts,” Dickinson said. “It raises all boats. So yes, there are indirect benefits for supporting wildfire management in the West.”
Closer to home, locals around Fort Stewart may wonder what impacts smoke has on climate change. Surprisingly, it is mitigated by prescribed burns, O’Brien said. The carbon in the smoke gets absorbed by the trees and plants. Some of the plants begin to sprout as soon as the flames die.
“You’ll see regrowth occurring almost immediately,” he said.
The reabsorption of the carbon into the plants creates black carbon that is stored in the soil, O’Brien said.
“The net amount of carbon in the atmosphere is being reduced by the formation of this char,” he said.
Louise Loudermilk, a research ecologist with the Southern Research Station’s Prescribed Fire Lab in Athens is focused on the regrowth of vegetation. She said humans have a long-standing relationship with fire, one that is slightly misunderstood. Studying prescribed burns on Fort Stewart allows that perception to be shifted.
“I want them to think a little more deeply about fire,” Loudermilk said. “I feel like there’s been a kind of disconnect through time on you know how humans actually sort of relate to fire. We’ve used fire for a long period of time…across generations or even hundreds and 1,000s of years. There’s a lot of different countries that actually still use burning to prepare the land. But in this case, it’s a little bit different because with prescribed fire, we’re actually sort of maintaining a habitat for multiple different types of endangered species. And that’s both plant and animal species.”
The team is using advanced technology to add in data collection. Light detection and ranging equipment —both handheld and airborne—was used to measure vegetation before and after the fire, Loudermilk said. The type of vegetation—everything from grasses and shrubs up to trees—growing in a wildland matters because that determines the fuel for the fire and how it behaves. Data gathered by other teammates on fire intensity is linked to the vegetation data.
“We try to put all those different components together,” she said. “We try to link that information that we collect with vegetation and link that to fire behavior, and also fire intensity, how quickly it might go across an area and fire effects.”
The eyes on the fire were even higher than the LIDAR-equipped helicopter flying overhead. Dickinson said satellites were observing the fires, too. The satellites were observing fire heat and fuel loads. The data collected will have direct applications for writing better prescriptions and fighting wildfires.
“Developing that is going to have some really direct benefits to wildfire management in the future, both delivering data to incident teams on the fires but then also doing measurements of how well fuel treatments are working,” Dickinson said. “There’s huge investment in doing fuel treatments but it’s really hard to tell how they work across landscapes and having good satellite info could really help us with that.”
Fort Stewart’s unique ecosystem also allowed Loudermilk to see how fire affects a blended system, where long-leaf pine meets low-lying wetlands with cypress trees. The pine land is dryer, while the wetlands, just a few inches lower, should be moist. Fire generally burns around those depressed areas, she said.
“What was interesting was that those wetlands were actually quite dry” Loudermilk said. “And so there was a decent amount of fire that went into those wetlands and that’s actually okay, wetlands are supposed to burn occasionally, just not as much as the area around it. But it was interesting to go out there and see it because it looks very different in terms of like what’s actually been consumed by the fire.”
The U.S. Forest Service team will take the data collected and create next-generation fire behavior models to better learn how to manage prescribed fires and prevent wildfires, not only in the southeast but across the United States. Analyzing the data is the day in the office for O’Brien.
“I go and put my suit and tie on and sit at my desk,” he said. “No, not really, but I do sit at my desk. My particular team is going to use this data to fine tune those next generation fire models which will be specifically designed to help prescribed fire managers.”