EAST OF URBANA, Ill. – At first glance, Trelease Woods looks like any other central Illinois woodland. There’s a well-worn track inside its fenced eastern edge, and the forest floor is littered with twigs and branches. But as I walk along the path with my companions, I notice that some of the trees are bigger than any I’ve seen in this area.
The woods are not open to the public, but I’m here with University of Illinois Urbana-Champaign natural areas coordinator Jamie Ellis, natural areas research specialist Nate Hudson, entomology professor Brian Allan and photographer Brian Stauffer. Today, Ellis and Hudson are guiding us on a tour of Trelease Woods and Brownfield Woods, two ancient 60-acre forests preserved by the university for teaching and research purposes. The university acquired Trelease Woods in 1918 and Brownfield Woods in 1939. They are remnants of the Big Grove, an old-growth forest that once covered about 15 square miles in present-day Champaign County.
A fallen tree in Brownfield Woods.
Photo by L. Brian Stauffer
We stop at one of the first big trees we see on the edge of Trelease Woods. It’s a white ash, with what Ellis estimates is a 60-centimeter (24-inch) diameter. Like most of the ash trees in central Illinois, this one is dead, killed by the emerald ash borer. As big as it is, it’s one of the lesser arboreal giants of these woods.
Leaves of an American basswood tree in Trelease Woods.
Photo by L. Brian Stauffer
Ellis guides us off the track and into the interior of Trelease Woods. We step around and over logs in all stages of decay. The decay is part of the plan, Ellis says. The U. of I. Committee on Natural Areas, which oversees more than 1,000 acres of university-owned territory, decided after a long debate that site managers would not actively interfere with the natural ecological processes underway in these two parcels. This means no tree cutting, no removal of brush and no prescribed burns.
Since 1994, researchers have identified and tagged every tree that has fallen in Trelease Woods and tried to determine when it died or fell. These data have been used in studies of decay and carbon cycles in the forest. This tree, a sugar maple, fell in May 2008.
Photo by L. Brian Stauffer
Ellis and Hudson do manage the perimeter – clearing bush honeysuckle from the forest edges, where this and other invasive plants often get their start. They toss fallen trees and branches back into the forest to keep paths and roadways clear. And apart from clearing invasive garlic mustard from the forest every spring, they don’t touch the interior of the forest.
“What falls in here, stays in here,” Ellis says.
I look down, hoping to see what the soil of an ancient, untouched forest looks like, and I’m surprised to see bare ground. There are accumulations of some types of forest litter – acorns, twigs, branches, hickory nuts and walnuts, for example – but there is no mat of decaying leaves. Ellis says this might be the result of earthworms brought to the Americas from other parts of the world. Even this “untouched” forest has been altered by human behavior.
The Big Grove, an ancient forest that encompassed about 15 square miles in Champaign County, once supported a thriving maple syrup operation. Sugar maples persist in many parts of Trelease and Brownfield woods and threaten to replace oaks, hickories and other species that do better in full sunlight.
Photo by L. Brian Stauffer
Ellis names the plants we see as we thread our way through the forest, and many of the names are unfamiliar to me. There is false nettle, clearweed, smartweed, stickseed, wild leek, bottlebrush grass and white grass – all native plants. He talks about squirrel corn, a plant with mildly toxic white flowers when it is in bloom. There’s also mayapple, another potentially dangerous plant with short stalks and umbrellalike leaves. Allan points to a single fruit dangling from one of the mayapples. It looks like a shriveled lime. Allan, Ellis and Hudson debate whether it would be safe to eat.
“May is when they’re poisonous,” Allan says. It’s July, but we trudge on.
Decay makes way for new life in Trelease Woods.
Photo by L. Brian Stauffer
Professors have brought their students to Trelease and Brownfield woods since before they were university property. In 1914, U. of I. zoology professor Victor E. Shelford, now widely regarded as the founder of animal ecology, brought his students to Brownfield Woods to explore and learn about the wild in-person. This was 25 years before the university purchased the tract as a permanent holding.
Natural areas managers leave fallen trees to rot and return their nutrients to the forest. Rotting trees also provide habitat to a multitude of fungi, insects and other invertebrates.
Photo by L. Brian Stauffer
We cover a lot of territory in Trelease Woods, and then get in our cars to make the short trip to Brownfield Woods. On the way, we pass through a tunnel of tree branches arching over the county road – a rare sight in this part of the country.
Some trees are uprooted by wind and topple over.
Photo by L. Brian Stauffer
Brownfield Woods feels grand. The trees are bigger here and it’s less brushy, giving it the feel of a wide ballroom studded with massive columns. Some of the trees here are enormous, including a gigantic, burl-pocked bur oak tree that dates back to the 1600s. Four of us stand around it, arms outstretched, to roughly measure its girth, and our fingertips only barely overlap. This means the tree has a circumference of about 24 feet. I stare up at this towering giant for a few minutes in awe.
This gigantic bur oak tree in Brownfield Woods dates to the 1600s.
Photo by L. Brian Stauffer
The trees here and in Trelease Woods include many species that are less common in the Midwest than they once were. There is American basswood, bur oak, chinkapin oak, slippery elm, red elm, shingle oak, hackberry, Ohio buckeye, blue ash and green ash. While white ash and green ash are susceptible to the ash borer onslaught, blue ash has so far survived, Ellis says.
Hundreds of researchers have made use of these two woodlands over the decades, and these and other natural areas owned by the U. of I. are vital to training students in ecological research. Such endeavors include camera-trap studies of wild mammals, collection and analysis of environmental DNA, long-term surveys of trees and understory plants, studies of ants and beetles, and analyses of the organisms that facilitate decay. Volunteers with the Champaign County Audubon Society visit these woods for the Christmas and spring bird counts. U. of I. scientists and students also hunt here for rare or endangered insects like the rusty patched bumble bee, study the habitat of tree-hole mosquitos, or collect cicadas and click beetles for laboratory research.
Brownfield Woods.
Photo by L. Brian Stauffer
“Trelease Woods, Brownfield Woods and other university-owned natural areas are important spaces for teaching and research,” Ellis says. “Field labs in ecology, entomology, ornithology, mammalogy, geology and other scientific disciplines provide important hands-on experiences for students to learn, discover and engage in the natural world.”
Source: news.illinois.edu
