MONTICELLO – The Weldon Springs Recreational Area, which sits next to Allerton Park in Monticello, is in the midst of some cosmetic work.
Hunters and hikers may notice rings carved around hundreds, possibly thousands, of non-native trees. The process, known as girdling, prevents the spread of nutrients from the roots. Girdled trees gradually rot out, sometimes taking more than a decade to fall.
Illinois Department of Natural Resources workers are eliminating Osage orange trees, honey locust trees and other invasive plant life.
The dead trees provide a home for more than 80 different species, including woodpeckers, bats and flying squirrels, according to Eric Smith, a natural heritage biologist with the Illinois Department of Natural Resources.
The department will replace the fallen trees with about 2,000 native oak and hickory trees.
"The native trees were not surviving under such a heavy canopy," Smith said. "Forty-feet-high trees shade out a big area. Some of the Osage trees were three feet in diameter."
As many as 2,000 trees have been girdled to prevent further destruction of native plants, Smith said, but he was unsure of the exact number.
"In the 1800s, ranchers brought the Osages here and used them as living fences," said Stan Etter, habitat team program manager for the Natural Resources Department.
The Osage oranges thrived because of advantages over plant life native to the area.
Deer and cows rarely feast on the resistant bark of the Osage orange, but deer will eat the tree's distinctive hedge apples, and squirrels spread the Osage orange's prolific seeds. This caused the species to spread throughout the 400 acres of department-regulated forest.
Etter said the honey locust also spreads aggressively, as do Hawthorn trees, another invasive species now targeted for elimination. But neither is as prolific as the Osage orange, a tree known for its hot-burning firewood.
Other non-native species targeted for elimination include the Oriental bittersweet, the multiflora rose and Japanese honeysuckle. The DNR will also reintroduce prescribed fire to the forest system.
Not all approve of the project.
"I don't like to see the trees go," said Monticello resident Chris Corrie. "Some of them are 100 to 200 years old."
But Smith said it's necessary for the good of the forest.
"Without management, the result would be a canopy of non-native trees and dense shrub layer full of thorns," he said.