This place is a unique kind of urban restoration. Van Vlissingen Park has been owned by the Chicago Park District since 2011. When we first started visiting, it was an overgrown, impenetrable, Phragmites-filled mess, like many public lands around Chicago in the 80s through early 2000s.
And the restoration isn’t back to some pre-colonial time; this is no remnant habitat here. It’s a spontaneous ecosystem that moved in on a bed of slag and construction waste. Some of the waste continues to erupt from layers of soil; bricks and building materials form vignettes highlighting the ever present human input into these urban ecosystems.
Now that it’s Marian R. Byrnes Natural Area, it’s a beautiful slag prairie and wetland, with a luxurious woodland path.
Alisma inflorescences from last year, and new vegetative growth
an honor for another explorer of underappreciated ecosystems to make his mark here!
with the water level down across the site, you can see balled up Nostoc, slowly dehydrating
slag to the left, woodland path to the right!a now-classic image of a high quality slag prairie!
I hadn’t been to this parcel – south of 87th, abutting the mouth of the Calumet River – in awhile, but I wanted to see what ephemeral ecosystem on Calumet slag barrens on the US Steel Southworks (USX) site will be lost when the Chicago quantum campus is built.
The USX site is one of the wildest greenspaces in Chicago – in a really unregulated state. Since most of the property is not under active land management, all manner of wildlife can wander around with little chance of interaction with humans. At dusk and dawn, large mammals are plentiful.
First, a little bit about this parcel. Unlike the north and central parcels of the site, this spot on the far southeast has arguably had the most disturbance due to development: fill has been added and graded around these ~40 acres since at least 2003. In 2011, Dave Matthews Band played a show, beneath “truckloads of wood chips … imported to cover the ground.” (I must return to hypothesize about differences in plant community on slag with, and without, this organically rich additive!)
Buildings were still at the site in 1991; by the year 2000, most structures were gone and there was a fence next to the Bush on the west so that the whole property was invisible to the public.
US Steel Southworks, 1991US Steel Southworks, 2000
Today, the vast open areas with crushed gravel-like slag can sustain wave after wave of short lived annuals that thrive in disturbed areas.
Other quadrants haven’t been regraded as recently, and here, copses of pygmy cottonwoods show us where nutrients and organic matter have collected.
I never thought of using the infamous Phragmites as an indicator species, but from our research on slag barrens, we have found the most interesting plant species in the depressions and wetlands of the slag barrens. In this case, the telltale seedheads (often confused for “prairie grasses”) belie the rare native orchids, sedges, and spike rushes that can similarly tolerate these damp human-modified sites. There wasn’t much to see in December around the Phrag, but it would be worth checking out in the summer, if the site is still accessible.
Elsewhere at the site…
South Slip
barge headed into Lake Michigan from the mouth of the Calumet River
We came up through the south end of Burnham Prairie, over several sets of railroad tracks. There was no parking lot; it just seemed like a close spot based on Google Maps.
We found a recent burn by Com Ed,
and skirted the wetlands of the Illinois State Nature Preserve.
We turned back and drove up to the north end of Burnham Prairie, well-hidden in the furthest reaches of residential Burnham, abutting the Grand Calumet River.
As we approached the slag prairie I realized I’d forgotten how much like Mars this slag is: everything is very stunted (very clear in cottonwoods); spotted knapweed is a champ and brings all the pollinators to the yard; there are a few Liatris, lots of whorled milkweed, some sumac; mosses making the barrens less barren.
the industrial corridor to the north belies a cottonwood glade atop concrete boulders, sunny meadows, blooms full of nectar for pollinators, a waterfront view, and carpets of moss.
In the great slag reconnaissance of 2022, we finally visited a whole host of sites from the slag map for use in botanical surveys next year. This looks like a spot that has the usual suspects, and some new friends, like the woolly plantain (Plantago patagonica) – a species I haven’t noticed on slag before!
I’ve been eyeing this site for a few years, never confident to visit it the first time alone. Who knew what was behind the overgrown tree-line at the edge of the lot?
We went together and it turns out that in late winter, perennial plants are greening up and glowing among the dreary cottonwood leaves. It’s a well-used place with past attempts at structures and social gatherings strewn about. No one else was here today though.
There’s a giant slag heap, one of the few in the area (but also: Shroud site, some parts of the old USX site). Holmes and Kubbing (2022) find slag heaps with ecosystems in Pittsburgh; in the Calumet Crescent we mostly see slag-filled depressions with slag as ground-level substrate. Remember that the Calumet was a vast wetland complex, yielding pockets in the landscape that were convenient to fill with steel production byproducts (e.g. slag) and other industrial waste.
The slag pile, or slag cliffs, rose up out of the woods of neighborhood volunteer junk trees: Ailanthus, ash, elm, cottonwood, a few juniper. The heap had clearly been used as a raised railroad spur, a way to transport in and out whatever was made here. To the east, these woods spread out and made way for big openings that have been used for ATV trails and bike jumps.
From the top of the slag cliffs, turning to the west was a delightful area with real promise: an ecosystem that grew up on slag and has created its own islands of organic material. A light canopy of slag-stunted rugged trees poked through diverse grasses. It looked like a slag savanna that may potentially be comparable to the high quality slag complex we see at Big Marsh and Marian Byrnes Parks?
It’s winter now, but this seems like a mesic area that might be wet enough for orchids?! I’d expect Liatris, hopefully Spiranthes, some sedges and rushes. We’ll revisit at the end of summer.
The bright blue sky and faded green of a warm early winter day. This place is wholly constructed now, atop swampy former wetland surrounding Lake Calumet – is there any remnant soil from that ecosystem? Or are all sediments so polluted it is unrecognizable beneath Phragmites and slag and a dune + swale landscape made from construction debris.
Calumet Region Adventure Club 