Chicago Botanic Garden

Woodland Ecosystems

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

PHOTO: burn in the woods Before the Chicago Botanic Garden was established, this woodland declined as a result of differing land uses, invasive species, fragmentation and fire suppression. In an effort to restore this native habitat and improve species diversity, the Garden now applies management practices such as controlled burning, brush removal and reseeding.

Garden scientists have conducted inventories to document the existing woodland conditions. Evaluation and ongoing monitoring of plant, small mammal, bird and insect populations provide a basis against which to evaluate future restoration progress and enable us to measure change over time. Much research in McDonald Woods addresses the important function of nutrient recycling. Exotic earthworms and invasive plant species affect woodland leaf-litter structure. This, in turn, effects soil invertebrates and litter-dwelling spider populations. Thus far, research has shown that exotic, invasive species are altering and disrupting natural nutrient cycling processes. Since all native plant communities are dependent upon naturally occurring levels of nutrients, these disruptions could affect plant health and our ability to restore our remaining native plant communities. A Garden research priority is to determine if existing restoration methods are addressing all of the harm done by invasive species and how best to monitor these vital ecosystem processes.