Dane County's historic oak savannas attempt a comeback.
Dane County's historic oak savannas attempt a comeback.
This is the first of a four-part series from Sam Harrington tracing a year in the life of Dane County's oak savanna restoration projects through the seasons. The above image shows an oak savanna at the Grady Tract of the UW Arboretum. Restoration work has been ongoing for ten years. All photos by Sam Harrington.
Winter is a quiet season in southern Wisconsin. The bugs are all hibernating, many birds are in their southern vacation homes, and snow insulates sound as well as soil. But, even though it's not at its most frenetic, life goes on.
Walking in the Grady Tract of the University of Wisconsin-Madison Arboretum in late February, I swore I heard an animal. I stood still, finger to my lips, waiting to hear it again. I did. But it wasn't an animal. It was a dead oak tree, fallen into the crook of a live one, and squeaking against it in the wind. Old oaks have a lot to say if you're willing to listen.
Oak trees are iconic members of the southern Wisconsin ecological community. One oak tree in the Grady Tract is estimated to be between 350 and 375 years old. Prior to European settlement and the violent displacement of Ho-Chunk people, oak savannas were the most common plant community in our area. According to the Wisconsin Department of Natural Resources, there once were about 5.5 million acres of oak savanna in Wisconsin. Less than 500 acres remain.
"Today they are extremely rare, one of the rarest communities in the entire world. Just a fraction of a fraction of a percent remains of original savannas, which is really unfortunate because that was our dominant community type in Dane County," says Lars Higdon, botanist/naturalist for Dane County Parks. A movement to bring oak savannas back began in the mid-20th century and continues today.
When you approach an oak savanna in the winter, the first thing you notice are the oaks. Unlike in woodland settings, savanna oaks are scattered far enough apart that they only shade 10 to 60 percent of the landscape.
Michael Hansen is the land care manager at the UW Arboretum. "Part of what makes savannas really interesting is there's all that variability in the light," Hansen says. "The light's doing different things with the shade and partial shade and it makes the plants that grow there really interesting."
Left to right: A liatris seed head in the Grady Tract savanna; A young oak protected by a wire cage in the Wingra Oak Savanna; Monarda seed heads at Pope Farm Conservancy
In the past, Ho-Chunk people managed oak savannas through fire and grazing. Wildfires were not suppressed, as they are today, and prescribed fire was used as needed. Bur oaks in particular are very fire-tolerant, and fires kept the savanna communities free from the shade of other trees and brushy undergrowth.
Despite the spread of monocultures of corn and suburbs, some remnants of those original oak savannas remain—particularly on slopes that were too difficult to plow. Many are overgrown with brush and woodland tree species.
One way to spot a remnant is if there are oak trees with widely outstretched branches. Like that 350+ year old tree in the Grady Tract. "You could tell it grew all by itself once upon a time," Hansen says. "It's got the big, open growing branches that kind of radiate out 360 degrees."
An oak savanna on a south-facing slope at Pope Farm Conservancy in the Town of Middleton.
In winter, while many plants and animals rest, restoration work in the savannas goes on. I recently read Katherine May's book Wintering in an attempt to teach myself to rest. In it, May writes: "Winter is not the death of the life cycle, but its crucible. It's a time for reflection and recuperation, for slow replenishment, for putting your house in order." This is true for people and for oak savannas.
Some of the first restoration work in oak savannas takes place in the winter when the ground is frozen solid and most plants are dormant. "Just like when you're remodeling a house, you start with the demolition, getting the nasty, rotten wood out of there, taking down all the old carpeting, getting wallpaper off the walls," Higdon says.
If you'd walked through the oak savanna at Stewart Lake County Park in Mount Horeb the morning of March 1, you'd have heard the booming of black walnuts being felled and the whirring of chainsaws. This part of the process can take visitors by surprise. People worry that perfectly good forests are being ruined, "when actually it's a community that's really suffering from all these invasive species and years of fire suppression," Higdon says.
At Stewart Lake County Park on March 1, 2022 volunteer sawyers and haulers were paired up to cut and clear brush from sections of the savanna. These photos show the before and after of the section that my chainsaw buddy, Phil, and I helped clear.
This type of confrontation happened at the Arborteum's Wingra Oak Savanna in the '90s. When restoration work began, residents of the nearby Dudgeon-Monroe neighborhood complained. So the Arboretum incorporated neighborhood leaders into the effort, and now residents help maintain and expand the savanna.
The volunteer organization Friends of Stewart Park is working to connect restoration efforts at the park to the Mount Horeb community by giving lumber from the felled trees to the school's Technology and Engineering classes (the modern-day woodshop). Students are also regularly involved in restoration work—from seeding and propagating plants to invasive removal—at the park. Mary McDonough-Sutter, a retired teacher, helps run the group.
"The savanna is an incredible teacher," McDonough-Sutter says. "The oak is a super majestic tree to be in the presence of, they're just so stately. And there's something about the presence of them within those grassy areas too, that it does really seem like it truly is a plant community. You know, there is an interaction there. That's pretty, pretty magical."
Most savanna restoration projects across Dane County rely on volunteers. The County and the Arboretum both have online calendars listing the dates for work sessions. Friends groups, like the one at Stewart Park, also have their own work days.
Volunteers and county parks staff cut and apply herbicide (mixed with a blue dye to help keep track of progress) to small trees and brush, and cut down larger black walnut trees at Stewart Lake County Park on March 1, 2022.
Many winter work days are focused on clearing brush and unwanted trees, but winter is also when seeding of understory grasses and wildflowers happens.
"The snow marks the seed very nicely and you can see your footprints and get good coverage that way," Higdon says. "It's also more or less the way that nature works. Because the seeds in the savanna are ripe in the fall, and then they're kind of blown away in the wind or moved by animals and deposited in the fall and early winter."
The seeds of some species of native plants require the exposure of a certain number of cold days before they'll burst open in the spring. I love that winter, in all its quiet harshness, is a beginning. Both the demolition before a renovation, and the seeding of a future garden.
Higdon says that though the County has been restoring oak savannas since at least the 1970s, the pace and scale of the work has increased in the last few years. The parks department hired another staff member, and they've been able to write more grants and carry out more restoration projects.
As the population of Dane County grows, naturalists and land managers hope that restoration allows people to connect with the history of the land, and make it part of the future. Communities of plants and grassland birds depend upon the existence of oak savannas to survive. And humans benefit from the ways that native plant communities manage stormwater, cool urban areas, and store carbon.
"They can have a strong future here in Dane County, in southern Wisconsin, if we choose to manage our lands for them," Higdon says. "It's not something that you can just do in a weekend. You've got to invest a lot of time. It's a process, a many-year process."
That process often begins in our most quiet season, the crucible of the life cycle: winter.
Oaks at sunset in Pope Farm Conservancy.
A note: If I'm honest, I was scared to start writing this piece! Who am I to tell you what an oak savanna means when I'm just beginning to understand myself? I've spent a lot of time with my neck craned backward staring at the uppermost reaches of beings three hundred years my elder, and so far, all I've been able to say to them is: "I'm sorry," and, "Thank you." But I will find more words, and throughout 2022, we will share seasonal dispatches from this most classic of southern Wisconsin landscapes. One year will never be enough to learn centuries of knowledge. But we must begin somewhere. See you in June.
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