Thorn Creek Woods

Description

Thorn Creek Woods is a 500 acre preserve with examples of upland, bottomland and ravine forests, glacial potholes, prairie and the aquatic environment of Thorn Creek. The original land survey, completed in 1834, indicates that the boundaries of the woods were very similar to what they are today, except for the southern edge of the woods which was probably an open oak savanna. Today, the forests on the slopes of the ravines are dominated by red oak. White oak is associated with red oak on the upper ravine slopes. Swamp white oaks dominate scattered poorly drained depressions in the uplands. Sugar maple, black maple and basswood are common on the lower slopes and ravine bottoms. The mesic sites support a rich and diverse herbaceous flora including many spring wildflowers common to the Chicago region such as yellow trout-lily, columbine, jack-in-the-pulpit and a variety of asters. A small area of wet and mesic prairie is located on the western edge of the woods. Prairie cordgrass dominates the low wet areas while little bluestem is more typical of drier areas. Common forbs of the prairie include wild hyacinth, Turk's-cap-lily, Culver's root, swamp saxifrage, swamp thistle, sand violet and sunflowers. Blue spotted and spotted salamanders breed in wetland depressions.