Setting the Stage for Restoration

Habitat Restoration Project Begins at Belleau Woods Forest Preserve

Setting the Stage for Restoration

Posted by Forest Preserve District of DuPage County | 4/23/21 7:48 AM

This winter, the Forest Preserve District began restoration of Belleau Woods Forest Preserve in Wheaton with donor funds dedicated by the Friends of the Forest Preserve District.

With a creek gently winding through a centuries-old oak forest, Belleau Woods stands as one of the county’s rare high-quality woodlands. Its woodland, shrub meadows, vernal ponds and small stream qualified its dedication as an Illinois Land and Water Reserve in 2013. The preserve supports 81 different species of wild animals, including the state-endangered black-billed cuckoo, and 310 native plant species, seven of which are regionally rare.

Today, however, invasive nonnative plants and shrubs continue to threaten this ecosystem, particularly its northern area.

The Forest Preserve District hired V3 Companies to help with the removal of invasive nonnative woody brush and small trees as a first step in returning greater diversity to the forest preserve.

What was once a high-quality oak savanna and prairie over many decades became overgrown with invasive and exotic plants — like buckthorn and honeysuckle.

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Invasive nonnative woody brush, including buckthorn and honeysuckle, are targeted for removal.

Natural resource project coordinator Nick Fuller, who is leading the habitat-restoration project, said the Forest Preserve District has performed an investigation about the site’s history. “Step one is to identify what plants were here before settlement and then eventual urban development,” he says. “This history helps to guide the conditions we will try to recreate in the community.

“If you look at an aerial depiction of DuPage County from 1939, this site will look dramatically more open than it is today. Perhaps up to 50 percent of the land was unwooded at that time.”

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Belleau Woods once flourished with large, fire-tolerant oak trees, as seen in this aerial map from 1939 (left).

An aerial depiction of the site from 1939 reveals that mature oak trees once dominated the area. Native grasses and wildflowers also grew in the wide, open expanses between these oaks.

The cessation of purposefully set fires by indigenous people during pre-settlement in addition to agricultural practices in later years likely contributed to the site’s present-day condition. “When Europeans moved to the area, they halted the use of fires to clear and maintain the land,” said Fuller. “They began to till the prairie, which was fertile, to create fields to grow crops. They also learned the surrounding woodlands were untillable and unviable for planting purposes.

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Invasive nonnative woody brush and small trees (left) have overtaken the northern half of Belleau Woods.

“In later years, farmers turned out their cattle to graze in these communities, which kept the woodlands open. Soon after, the woody vegetation started to come back. First it was the native plants; then nonnatives were introduced to the sites.

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Farmers once grazed their cattle in oak woodlands in DuPage County, depleting native grasses and wildflowers and even damaging young saplings.

“Over that short time period from the 1940s to present day, all of the woody plants grew in this area. So if we do not change that trajectory, we won’t have the wildflowers, we won’t have the grasses, and we won’t have the oak seedlings to replace those oaks that are aging out across DuPage.”

Fuller went on to discuss the restoration work performed at the site and the conditions that would be favorable for its future management.


“We’re in Belleau Woods today, and we have some gracious funding from our private funders. And we’re doing some restoration in here. So what our crew is doing today is we are cutting invasive brush.

“What we’re trying to do is to set the stage to make the site in a more burnable condition. So we have some overstocked native trees that are fire-sensitive, and we also have some invasive species that are fire-sensitive. But to be able to let nature rebalance those with fire, we first have to set the stage by making a prescription to make the site first burnable. Because in its current state, it is not burnable.

“So we are looking to get enough light down to the ground to be able to grow a native herbaceous layer so that that establishes enough native fuels in here to be able to carry a fire through the site.

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The native oak sedge is an important understory plant with deep roots that will fuel a prescribed burn.

“And then once we are able to carry a fire through the site, the fire — or Mother Nature with the fire — helps rebalance the woody invasive plants versus the native woody plants and also versus the herbaceous layer of the wildflowers and grasses.

“So if we don’t do this, a lot of the overstory here is an oak woodland. If we don’t have oak regeneration to replace the mature oaks that are in here ... a lot of the oaks in the Chicago area, they're starting to age out. They're 150 years old plus, and if we don’t have enough young seedlings of those oak trees to replace the aging out oak trees, we will not have an oak woodland anymore.

fallen-oak-woodland-Belleau-Woods
Many of the red oak trees and other native species in this woodland are no longer regenerating to replenish the community.

“And so the important thing for those oaks is they need a ton of light. They need, I would say nearly part-sun to full sun to get from an acorn to a seedling to the most critical bottleneck — from the seedling to the sapling phase and then onto maturity — so that they again are reproducing, and it’s a self-sustaining system.

“We’re trying to kick that off so that Mother Nature can then get that full circle and be self-sustaining.”

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An oak sapling will tolerate the future use of fire to manage the area.

The site’s native and fire-tolerant oak, hickory, walnut and other trees will remain to flourish under improved conditions. Likewise, native grasses and wildflowers in the community’s understory will regenerate from increased sunlight in the community.

Most of the work will finish by late April at the forest preserve, but additional work will continue through winter of 2022.

Belleau-Woods-oak-woodland

Sunlight nourishes native oak, shagbark hickory and walnut trees in the southern area of Belleau Woods Forest Preserve.

Topics: Natural resources, Plants, Conservation, Friends of the Forest Preserve District, restoration

Written by Forest Preserve District of DuPage County

The Forest Preserve District of DuPage County manages nearly 26,000 acres in 60 forest preserves containing prairies, woodlands and wetlands.