Nachusa Grasslands restoration: Invasives, controlled burns and seed harvests
This is the 7th in a series of articles by Knight Center students who attended the 2026 annual convention of the Society of Environmental Journalists.
By Anna Ironside
For over 40 years, restoration efforts have been happening at a prairie in northern Illinois.
The Nachusa Grasslands near Franklin Grove has a team of scientists and volunteers helping to rebuild the endangered ecosystems through seeding and scheduled controlled burns.
Nature Conservancy researchers spoke on how the goal for the prairie is to aid in reassembling the ecological process that had sustained the land for thousands of years.
According to the Nature Conservancy website, in 1985 a small area of tracts in what is now the preserve went up for sale. Many donors and supporters contributed, which helped the Nature Conservancy buy the land at auction. At the end of 1986, TNC owned 397 acres.
“Our goal here is to set up the tallgrass prairie ecosystem for success into the future,” said Elizabeth Bach, a research scientist based at Nachusa.
“We’re talking about bringing these plants, animals, soils and ecosystem functions and processes back together to thrive and persist into the future, knowing that the future looks quite a bit different than our past has.”
She was speaking to members of the Society of Environmental Journalists who visited Nachusa as part of their annual conference.
Bach, who specializes in soil and plant ecology, said restoration at Nachusa depends on two of the prairie’s most important forces: fire and seed. Every year, the land managers conduct prescribed burns across sections of the preserve to mimic the natural and Indigenous-set fires that historically shaped the area.
“We do prescribe fire in a way that is very conscious of achieving our ecological goals,” Bach said. “There’s a lot of planning that goes into it. We have a written plan, we have to get smoke permits, and we all are trained.”
Tyler Pellegrini, plant and soil ecologist at the Machusa Grasslands, explaining prescribed fires to a group o SEJ members. Credit: Anna Ironside
She explained that crews of researchers and volunteers use carefully planned ignition patterns to better control the direction and intensity of the burn.
“You start on the downwind side and light what’s called a backing fire that burns real slow and controlled into the unit,” Bach said. “Then you burn along the sides – that’s a flanking fire – and then by the end, you light one head fire and the winds push it far into the unit.”
These burns are not only a management tool, but they also clear out invasive species and recycle nutrients, while triggering native plant growth.
“We can suppress that brush by doing prescribed fire very frequently,” Bach said, referring to invasive woody plants like honeysuckle.
The burns are only one step in the process of rebuilding the prairie. Seeding is another large part of the restoration effort.
Dozens of barrels of different seeds are processed and ready for distribution across the Nachusa Grasslands. Credit: Anna Ironside
Staff and volunteers collect and distribute millions of native seeds every year, working to reconstruct the plant communities that were plowed under for agriculture over a century ago.
“If you don’t put enough seed down, you get a lot of invasive species pressure,” Bach said.
Years of studies and research at Nachusa have helped to determine how much seed is needed to build up diverse prairie communities, which have been a useful guide for restoration work throughout the Midwest.
“Most years we have around 30 research projects happening at the preserve and we’re collaborating widely across a lot of universities and research agencies,” Bach said.
Bach added that the results are slow but measurable.
In the early years, newly seeded fields filled with weeds before native species established themselves in the soil. Over time, diversity has increased, and deeper-rooted prairie plants have stuck around.
“Usually, in five to eight years, you’re seeing most of the species that you’ll end up seeing,” Bach said. “But restoration is kind of a never-ending process.”
The brown grass towards the back of this photo shows previously controlled burns on the prairie at Nachusa Grasslands. Credit: Anna Ironside
Prairie soils can regain carbon over decades, but full restoration takes much longer.
“About 80 to 90% of that happens in the first probably 50 to 80 years,” she said. “But to get back to remnant prairie levels, it’s probably going to take 150 to 300 years.”
The combination of fire, seed and long-term monitoring is reshaping how conservation is done in the area and other parts of the region.
“We’ve tried some things, we’ve learned some lessons, we’ve made changes,” Bach said. “We’re summarizing all of these plantings and how our practices have changed and how the resulting prairie outcomes have changed.”
Some of the approximately 130 bison that roam the Nachusa Grasslands. They were reintroduced to the land in 2014. Credit: Anna Ironside
When talking about the future and the long timeline that this work is on, Bach sounds hopeful, and her organization will continue to do work that cannot be measured by just a few seasons.
“We want to see this ecosystem thrive for generations to come,” she said. “We do things every day that we know we are not going to see the outcome or the rewards of.”
Anna Ironside
