McDonald Woods | Skokie River | Dixon Prairie

While oak savanna and woodland once dominated much of northeastern Illinois, today only fragments of these rich and thriving communities remain. McDonald Woods is the Chicago Botanic Garden's naturally occurring oak woodland community of plants and animals. Differences in soil type, moisture and topography have resulted in a diverse complex of plant associations within this 100-acre site. The nearly 300 species of plants support more than 100 species of birds, 20 species of mammals and countless insects. Many of the plant species found in McDonald Woods are no longer common in the region, and several, including Geranium bicknellii (northern cranesbill), Aster furcatus (forked aster) and Viola conspersa (dog violet), are either threatened or endangered in the state of Illinois. One species, Deschampsia flexuosa (hair grass), is found nowhere else in the state.

Prior to the Chicago Botanic Garden's formation, land practices, invasive species, fragmentation and disruption of natural processes resulted in a decline of this woodland. The Garden is now applying accepted management practices to the restoration of this native habitat. Prescribed burning, brush removal and reseeding are methods being used to improve species diversity and return function to the community. Many studies have been undertaken to describe the existing conditions in the woodland. Evaluations of plant, small mammal, bird and insect populations provide a basis against which to evaluate future restoration progress. Many components of the community are being monitored for change. Specific research projects are focusing on soil organisms, nutrient cycling, fungi and threatened plant species.

Dixon Prairie

Even in the "Prairie State," native tallgrass prairie is rare, for only about 1/10 of 1 percent of Illinois' original prairie land remains. Much of that acreage occurs in the Chicago region, protected in nature preserves, and the Chicago Botanic Garden's Suzanne S. Dixon Prairie is one of these treasures.

The Dixon Prairie was established to help educate visitors about the diversity of prairies in the Chicago region. The extensive representation of plants in this region is a result of a very active glacial past, which created varied soils and landforms supporting different prairie communities. At the Dixon Prairie, many of these communities have been recreated in a 15-acre exhibit featuring interpretive programs and signage. Included are mesic (moist), wet, gravel hill, fen and sand prairies, as well as a bur oak savanna, sedge meadow and marsh communities. These communities support more than 250 species of prairie plants.

The diversity of prairie in the Midwest could not exist without the influence of fire, which prevents trees and shrubs from encroaching and shading out the prairie. At Dixon Prairie, controlled burns help suppress the invasion of both woody and herbaceous weeds, while they also encourage fire-tolerant prairie species. Because weeds are well adapted to the disturbed soil environments of a recreated prairie community, active research on soil management is ongoing. Investigating the complex interactions between plants and animals in recreated landscapes, above and below ground, is also a research priority in the Prairie.

Skokie River

Flowing through the Garden is a mile-long stretch of the Skokie River, which is typical of channelized waterways in urban areas. This are was originally maintained as turf grass, but beginning in the mid-1990s the Garden sought to reclaim some of the natural habitats and function within the Skokie River Corridor. This area now serves as a demonstration to others of possible river restoration, enhancement techniques and alternatives to a "hardscape approach" for bank stabilization.

Excessive streambank erosion is addressed through vegetative bioengineering methods: installing coconut fiber bundles, willow posts and brush layering and planting prairie cordgrass (Spartina pectinata). A 12-acre riparian buffer of wetland and prairie habitats is being developed, with the objective of having a sustainable matrix of native species dominated by gasses and sedges. Currently 197 native plant species grow in and along the river, including 32 sedge and 22 grass species. Traditional restoration management techniques, including prescribed burning, are used to develop and sustain this urban waterway.

The goal of this river enhancement work at the Garden is to develop, study and interpret diverse and sustainable communities of native plants and animals. Studies seek a watershed approach to the challenges of severely modified or degraded river systems, including extreme water fluctuations, high sediment and nutrient loads, low dissolved oxygen, engineered soils and the presence of invasive species.