Biologists throughout Southern Illinois are employing an ecological restoration program known as Let the Sun Shine In.
The aim of the program is to maintain the health of oak-hickory forests in the region. The theory is sunlight must be able to reach the forest floor so shade-intolerant species such as oak and hickory can replenish. In addition, additional sunlight reaching the forest floor will allow grasses, sedges and wildflowers to flourish.
“I do think the oak decline is an invisible problem,” said Mike Baltz, director of Shawnee Resource, Conservation and Development. “People just drive by and go, ‘Oh, trees.’ Not because they are not smart, it’s just that it doesn’t jump out at you."
As the oaks are disappearing from the forest, what you have in a lot of these forests are big white, red, black oaks are beginning to die. We haven’t had an acorn shortage, but the old oaks are beginning to die. Who is coming in behind them? That’s a problem if you like deer hunting, turkey hunting.
In this succession, shade-tolerant species such as beech and maple take over. A brochure produced by Southern Illinois University states that the forest understory at Trail of Tears State Forest consists of just one percent oak and two percent hickory. In 1980, the forest overstory was 36% oak and 11% hickory. A 2014 survey indicated those numbers had dropped to 21% oak and 10% hickory.
“Not only do they (beech and maple) not produce a big obvious acorn or a nut, oaks are much more insect-ridden,” Baltz said. “As far as migration, the oak leaf-out and the timing of that migration especially and all the caterpillars that are associated with that, you have oaks, hickories and sassafras, and other mast producing trees are just getting shaded out. You have the huntable wildlife, but also as far as the non-game, the forests are becoming less attractive to birds as far as a place to find food.”
The steps being taken to mitigate the problem include prescribed burns and the thinning of maple and beech. The small maple and beech trees are left on the forest floor and are part of the prescribed burns.
The mitigation measures have raised the ire of the environmental community. The agencies conducting the work on federal, state and private property maintain it is important to look at the past when working toward the future. They say the historic nature of the forest is guiding their work.
Jean Sellar of Cobden, who is on the board of the Sierra Club and Native Plant Society, is a semi-retired restoration ecologist. She has helped restore 10,000 acres of forest, savannah and prairie land.
“I think it is important restore the community that is native to the site,” she said. “Down here, most of it is oak woodland with scattered prairie openings and savannahs. One of the things we do is research the history and physical features of the sites. There is a lot of work that goes into the sites.
“It’s important to do it correctly, that’s my only cautionary point, which is why I emphasize the kind of background information we gather before we start on a site. Let the Sun Shine In is certainly doing that.”
Anyone interested in seeing what the work looks like can visit the Devil’s Standtable area of Giant City State Park. Some thinning has been done, and there are signs marking the spots.
On private land, ecologists work with landowners to create a Timber Stand Improvement plan.
Beecher Williams of Herod said he has implemented similar procedures on his land for decades.
“The difference now is we have a lot better quality of hardwoods, our oaks and our hickories,” he said. “We have a lot better quality, we have a lot less of the maples, sycamores and elms, the understory type. What I like about it is, you don’t necessarily want your forest to look like a park, but at the same time you don’t want it full of understory stuff that changes the ground.”
Williams said some of the family’s timber land is subject to harvest, but it is also used for hunting.
“These forest plans don’t allow clear cutting,” Baltz said. “It’s such a beautiful system. It’s such a win-win. A landowner has a forest plan written by a DNR forester, in order to qualify for this program they have to have a forest plan approved by a forester which would not allow overharvesting. There is a control there on the private land.
"A lot of times it’s not until you walk into a patch of forest like at Wildcat Bluff, or Devil’s Standtable where IDNR is starting to do some work. It’s a little bit open. The sun is starting to come in, and all of a sudden the native sedges, all this herbaceous layer, with the herbs come the pollinators. When you walk through the woods, you see butterflies along trails, that’s the only place you see any light. It’s an invisible problem that is impacting a lot of our wildlife.”