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Sag Valley Dolomite Prairie and Fen

Location: Cook County, Lemont Township, T37N, R11E, Sec. 13
Size of area affected by MSCSF-funded work: 60 acres
Resulting Illinois Nature Preserves Commission Land & Water Reserve Dedication: 150 acres
Owner: Forest Preserve District of Cook County (FPDCC)
Partners: FPDCC, USACE, CorLands, Northeastern Illinois Wetlands Account (TCF, USFWS), Illinois Nature Preserves Commission

Action: Creation of a restoration management plan for slightly over 100 acres, cutting and herbicide treatment of woody vegetation, selective tree removal, follow-up treatment of resprouts, control of invasive herbaceous species, seeding, and conducting controlled burns.

Summary: Located near Cook County's only true canyon, Sagawau Canyon, is the Sag Valley Dolomite Prairie and Fen. It's part of a large complex of natural areas, and is connected to the largest concentration of open space in Cook County, the Palos/Sag Valley Forest Preserves.

Amidst its assortment of high quality plants is a good variety of wildlife. The area is an epicenter for snakes; queen snakes, banded water snakes, northern brown snakes, smooth green snakes, and Chicago garter snakes are a few of the species found here.

The site was mapped, and a restoration plan developed. A hydrological study was also conducted; before beginning, land managers wondered whether it might be a good idea to remove a berm along the north end of the fen, but the study determined that this wasn't necessary. No significant changes were made in the hydrology of the area.

The dolomite prairies and the fens were severely overrun with brush before beginning this project. Mike Konrath, the director at Camp Sagiwau, says that he's been working at the site since 1984; when he started, there were just small shrubs, but over the years, he watched it fill in to solid stands of brush. Surveys conducted before the work began showed that there were a million stems of buckthorn per hectare in some areas. Some of these were quite large, and because of the Forest Preserve District's moratorium on cutting down trees larger than four inches in diameter, only the smaller trees were removed. The conditions of the moratorium have been changed, and therefore the larger trees should now be removed. Several prescribed burns have been conducted.

Impressive results have already been observed as a result of the brush removal and burning. Soon after, a flock of 200 sandhill cranes spent the night in the newly-cleared area. One pair stayed to nest. Other birds, such as killdeer, woodcocks and red-tailed hawks nested right away, and in 2004, turkey vultures nested and raised their young in the base of a hollow tree. According to Konrath, before the fen was cleared there were 50 plants of angelica; now there are 250. There has also been a dramatic increase of toads in and around the fen.

In 2004 CorLands received a grant from the National Fish and Wildlife Foundation to expand the restoration area at Sag Valley from 60 to 85 acres. Buckthorn and honeysuckle removal on the 25 acres was completed during the winter of 2004/5. Woody resprout and herbaceous invasive control in and adjacent to the newly cleared area was conducted during the spring and summer of 2005. Funding remains under this grant to continue the treatment of woody and herbaceous invasives within and adjacent to the restoration area in 2006.