Woodlands along the Des Plaines River. Photo © Chip Williams.
At first glance, the woodlands along the Des Plaines River in southern Lake County appear healthy. However, extensive research shows that most of the oaks are very old and very few young oaks are growing in the understory to replace them. This is having a domino effect on native animals, such as songbirds and butterflies and the native shrubs and wildflowers they require.
Beautiful oak woodlands define the unique natural landscape of Lake County that we all enjoy. Oak trees create an environment that maintains critical ecosystem processes and species diversity.
Unfortunately, oak woodlands are in trouble across the eastern United States, particularly so in this area. We need to return the amount of light that reaches the ground to healthier levels. This will allow for the regeneration of oaks and other native trees, shrubs, and wildflowers.
Without action, our oak woodlands will not survive. They will be replaced by denser, darker forests that lack the rich and colorful variety of songbirds, butterflies, wildflowers, shrubs and other abundant forms of life we value as a community. The Lake County Forest Preserve District is in the ninth year of a long-term effort to restore our oak woodlands, which includes a phased plan to increase light levels in the understory by removing trees canopy. The goal is to improve conditions for natural oak regeneration, improve habitat for woodland birds and amphibians and increase the diversity of native shrubs, grasses, sedges, and flowers in the groundlayer. Preliminary data show that the first phases of canopy thinning have increased light levels and that oak seedling survival is greater in areas where we have opened the canopy. Overtime, monitoring will continue to advance our understanding of how to restore our oak woodlands.
This winter, we will complete the final phase of canopy thinning at MacArthur Woods, Captain Daniel Wright Woods, and Ryerson Conservation Area.
The project areas include:
MacArthur Woods | Mettawa
Selective clearing within a 42-acre section of woodland that were originally thinned in 2012.
Ryerson Conservation Area | Riverwoods
Selective clearing within a 67-acre section of woodland originally thinned in 2012.
Wright Woods | Mettawa
Selective clearing within a 49-acre section of woodland originally thinned in 2012.
Goals of this restoration project are broad reaching and long-term:
Restore light transmission in these woodlands to 30–50 percent
Increase oak regeneration and the diversity of tree species and sizes
Restore the abundance and diversity of native shrubs and ground-layer plants
Create a mosaic of habitats, improving conditions for plants and wildlife
Our efforts to improve oak woodlands are supported by Chicago Wilderness, Illinois Nature Preserves Commission, Illinois Department of Natural Resources, Morton Arboretum, U.S. Forest Service and U.S. Fish and Wildlife Service. These expert partners, as well as Chicago Botanic Garden, Illinois Natural History Survey and Lincoln Park Zoo, will help us monitor plants, animals and environmental conditions to evaluate success of this project for years to come.
This project was featured in the Summer 2012, Winter 2012, Fall 2013 issues of our quarterly newsletter, Horizons.
To schedule an educational presentation about this project for groups of 10 or more, or to request copies of the Woodland Habitat Restoration Project Summary and Report and Frequently Asked Questions, email or call us at 847-367-6640.