The Marian R. Byrnes Natural Area in Chicago. (All photography by Jason Smith)
The beauty of slag
An alvar is a strange, barren landscape: a flat sheet of limestone with just a sprinkling of loose soil on top. You might think nothing could grow there, and yet somehow, alvars host their own tough little communities of rare plants. Sometimes even trees. Severely stunted trees, but trees nonetheless—natural bonsai. “It’s like they’re growing on a parking lot,” says ecologist Alison Anastasio, SM’05, PhD’09.
Anastasio first visited Stora Alvaret (Great Alvar) in 2008 when she was in Sweden doing fieldwork for her dissertation. The alvar had nothing to do with her research, which focused on a plant known as thale cress or mouse-eared cress (Arabidopsis thaliana). But she was fascinated by this apparent wasteland that was home to all kinds of plants and animals: “What a beautiful, amazing ecosystem.”
A few years later, back in Chicago, she visited a less romantic landscape, the former US Steel South Works site on the southeast side of the city. It’s covered with slag, a byproduct of steelmaking. Slag was dumped while it was still molten. Like flowing lava, it killed everything it touched, then hardened into a substance similar to asphalt. At the US Steel site, Anastasio found cottonwood trees growing on it.
Cottonwoods are usually enormous—100 feet tall or more. These cottonwoods were stunted down to human size, closer to six feet. They made Anastasio think of the tiny trees she’d seen on Stora Alvaret.
When she looked more closely at the vegetation, she expected to find “all crap plants”—the same invasive, non-native weeds you might see in any vacant lot. To her surprise she spotted little bluestem, a native prairie grass, as well as three species of native milkweed. And the US Steel site is “not even one of the most exciting slag sites,” she says.
Anastasio had already completed her PhD and decided she did not want a career as an academic scientist. Nonetheless, a research idea was born.
Lauren Umek (left) and Alison Anastasio, SM’05, PhD’09, search for a rare sedge in the Marian R. Byrnes Natural Area.
That former mill site sits in the Calumet Region—sometimes called, more poetically, the Calumet Crescent. The region begins on the far South Side of Chicago and hugs the Lake Michigan shoreline into Indiana. Its ecosystems include dunes, oak savannas, prairies, wetlands, and woodlands.
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