Illinois Natural History Survey - University of Illinois

Plants of Site M, a True Macrosite

Most natural areas in Illinois are small, isolated, and surrounded by urbanized or agricultural lands. Resource managers face a daunting task trying to preserve the natural qualities of these areas.

To assist this process, the state is attempting to establish "macrosites"--large natural areas with unified management goals. Most macrosites consist of lands owned by several organizations or individuals, all of whom agree to manage their holdings for a common goal. But building such agreements can be difficult and time-consuming. Management is much easier if the entire macrosite belongs to a single owner.

One of the state's newest conservation and recreation areas is known as Site M. This area is in Cass County, about 30 miles from Springfield, and consists of almost 24.5 square miles in a single contiguous holding. Commonwealth Edison Company originally acquired the land for a coal-fired power plant and cooling lake, but decreasing electrical demand eliminated the need for such a facility. In 1993, Site M was purchased by the Illinois Department of Conservation.

The first step in developing management plans for Site M is a comprehensive inventory of the area's natural resources. We contracted to inventory the plants and found that although the land now has a single owner, its history of diverse ownership resulted in a mosaic of habitat types of widely varying natural quality. About half of Site M is cropland, much of which will be leased to farmers, thereby providing income to support the restoration and management of the rest of the area. Another 20% is pastureland. Cattle have been removed from most of Site M, but their impact is clear, not only on the former pastures but also throughout the area, including the forests that cover another third of Site M. Much of the forest had been partially logged, and with the grazing has resulted in woods that are dominated by small trees, such as hawthorns (Crataegus spp.), wild crab apples (Malus spp.), and Osage orange (Maclura pomifera); and by shrubs like raspberries, blackberries (Rubus spp.), and gooseberries (Ribes missouriense) that are unpalatable to cattle.

Still, there are patches of woods that, because of steep terrain, natural barriers like creeks, or the former owners' management, retain higher quality. These forests have a diversity of tree species and sizes, and a good diversity of spring woodland wildflowers. Other scientists have found that these areas are also home to rich birdlife and to the federally endangered Indiana bat (Myotis sodalis).

INHS researchers Geoff Levin (L) and Rick Phillippe (R) examine plants on a hill prairie at Site M. (photo by Kenneth Robertson)

Botanically, the most significant vegetation type on Site M is hill prairie. Found on slopes that are too steep to cultivate, hill prairies require periodic burning to exclude trees and shrubs. The largest series at Site M is found in the Cox Creek Hill Prairie Natural Area. With restoration of adjacent pasturelands that appear to be former prairie, this area has the potential to become the largest hill prairie complex in the state. Although hill prairies account for less than 1% of the area of Site M, they are home to large populations of two threatened species in Illinois: Hill's thistle (Cirsium hillii) and pale false foxglove (Agalinis skinneriana). Site M hill prairies also contain Illinois' only known population of the state-endangered white lady's slipper orchid (Cypripedium candidum) surviving outside northeastern Illinois.

Two other state-threatened plant species are found at Site M. Two small populations of Nieuwland's blazing star (Liatris scariosa var. nieuwlandii) grow in highly disturbed forest edge sites. Much to our surprise, we also found several populations of large-seeded mercury (Acalypha deamii) along the floodplain and small tributaries of Cox Creek. Confined in Illinois mainly to the Wabash River drainage, this species had never been found so far northwest in the state.

With these inventories complete, the Department of Conservation can now develop management plans for Site M. Though degraded by logging, cultivation, and grazing, the forest and prairie habitats have the potential to be restored and enhanced. Plans are also under way to develop appropriate recreation opportunities like hiking, camping, hunting, and fishing. With its large size and diverse resources, Site M will be an ideal place to demonstrate the merits of macrosite management. This inventory also illustrates the ongoing cooperation among Illinois' natural resource-oriented agencies in meeting the state's conservation needs.

Geoffrey A. Levin, Loy R. Phillippe, and Kenneth R. Robertson, Center for Biodiversity

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Last Modified 3/19/96

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