A November 2017 Field Note by Phoebe Thatcher, TWI Development & Communications Assistant and fire enthusiast
For the Wetlands Initiative’s Rick Seibert and his crew, fighting invasive species at the Dixon Waterfowl Refuge can be an uphill battle. Fortunately, TWI has a powerful ally in the form of fire. Despite what Smokey the Bear told us about forest fires, modern ecologists have found that regular burns are not just beneficial, but necessary, for the management of healthy prairies and wetlands.
The Wetlands Initiative has always used fire as a management tool and this fall’s burn at the Refuge was one of the biggest yet in terms of acreage. As TWI's Development & Communications Assistant, I spend most of my time at the Chicago office, writing emails and updating our website and social media. I’m also lucky enough to have earned my Chicago Wilderness Burn Crew certification, which is why I got called out into the field to lend a hand this burn season.
The day before Thanksgiving marked the first major prescribed burn at Hickory Hollow, a new addition to the Dixon Waterfowl Refuge where restoration is in the early phases. “The first few times you burn, there’s not enough fuel,” said Rick Seibert, the Refuge’s site manager and “burn boss.” But as time goes on and prairie plants begin to take root, he added, “You get better burns, there’s no doubt about it.”
Many of the most tenacious invasive species—buckthorn, honeysuckle, and autumn olive—are easily damaged by fire because of their shallow root systems. Meanwhile, native perennials like prairie dock and big bluestem, whose roots extend up to 14 feet below the surface of the soil, can survive the temporary heat. Some native plants even have seeds that germinate only after contact with fire. In woodlands, fire removes the understory of dead and dying annuals so that fire-resistant oak seedlings have more access to nutrients and sunlight. Dead trees hollowed by fire provide habitat for woodpeckers, minks, weasels, and other wildlife. Fire is a powerful tool for creating and maintaining healthy native habitats.
Of course, the state of Illinois won’t let just anyone take a match to a prairie. There’s a lengthy application process for getting a burn permit from the state EPA, and burn bosses like Rick need to take certain classes to be allowed to conduct burns.
Our November morning at the Refuge was almost perfect—a clear day with good sun, temperatures just cold enough to freeze over Hennepin & Hopper Lakes, and a gentle wind to disperse smoke. Together with the Refuge’s team of restoration technicians, TWI’s Midewin field crew (visiting for the occasion), and Assistant Ecologist Anna Braum, I loaded up the four-wheelers with the tools of the trade: heavy steel cans called “torches” that disperse lit gasoline; rakes and rubber “flappers” for snuffing out escaped sparks; and a big tank of water in case any sections of the burn need to be contained. Technicians rely on a suite of tools and techniques to keep prescribed fire under control. For burn bosses like Rick, a day of burning can take months of planning and weeks of waiting for just the right conditions. “It takes a lot,” said Rick. “You have to plan ahead, you have to be ready to go. Not everything burns the way you want it to burn.” He added, “Which is good.”
Even with all that planning, things didn’t initially go as expected this fall. The team started by trying to “drop fire” along the line between the Refuge and a neighbor’s farm, with technicians standing by to make sure no stray fire escaped. The ambient humidity proved a little too high and even the dry, dead Canada rye at the fringes of the restoration wouldn’t catch, so we retired for about an hour to eat lunch and tour the Refuge’s Dore Seep. The humidity dropped about 8 percent as the sun burned some of that morning’s frozen dew off of Hickory Hollow, and we tried the torch again. This time, the vegetation caught like a dream. The burn was on.
Divided into two crews, we cut through the whole of the Hickory Hollow tract. While we dropped a line of fire on one side of a field, Rick’s crew did the same on the other side; this way, the two burns met in the middle of the field, mitigating the risk of the fire jumping from one portion of the preserve to another.
The sight, smell, and sound of the fire was amazing. Imagine a crackling fireplace at 20 times the volume, a light rain of ash falling gently from the sky, and a heat so intense you can feel it from 15 feet away. By the time Anna and I got back in the car to return to Chicago, we were exhilarated—and exhausted. We’d done what we set out to do.
Dr. Gary Sullivan, TWI’s senior ecologist, says his goal with this year’s burn was twofold: to knock back invasive species and to create a base of “carbonized mineral soil, black soil, that will absorb heat in the spring and help seeds to germinate.” Those seeds? A blend of Illinois natives such as nodding wild onion, wild white indigo, and purple prairie clover that will help transform the new tract back into the sand-based prairie and savanna it was long ago. Sullivan expects to sow about 530 pounds of live native seed before green-up next spring, when plants will come out of their dormancy and the Dixon Waterfowl Refuge literally rises from the ashes.
To an outsider, fire may seem like an unconventional way to manage a nature preserve, but for the Wetlands Initiative it’s working. The proof is in the prairie.