Southwestern Illinois RC&D, Inc.

Southwestern Illinois RC&D

For the past three years the Southwestern Illinois RC&D, Inc. has assisted the Illinois Natures Preserve Commission in obtaining funding to remove invasive species on hill prairie sites in the region. The mostly contiguous bluff line that extends from Dupo in southern St. Clair County, to just south of Prairie du Rocher in Randolph County, contains 13 sites comprised of 3,900 acres listed on the Illinois Natural Areas Inventory. Of particular significance at these INAI sites are numerous hill prairies and limestone glades, two natural communities that are increasingly rare in Illinois. This stretch of bluffs contains a greater concentration of existing hill prairies and glades than any other area of this size in the state. The primary cause of decline of these sites has been encroachment by woody species, due to the absence of fire. Some hill prairie and glades along the bluff line have completely disappeared since the INAI was completed in 1978. In addition, the prairie and forest communities are being invaded by exotic species such as sweet clover, bush honeysuckle, and tree of heaven.