The Conservation Commission works to preserve, protect, and restore the natural resources of the Village of Brookfield through education, outreach, and community involvement.
Natural Areas Managed by the Commission
Brookfield’s Oak Savanna and woodland at Kiwanis Park is a unique natural resource. It provides an open natural area for recreation for residents complete with trails and interpretive signs created with grant money from Chicago Wilderness. It provides habitat for wildlife and interesting plant species. And, the savanna itself is a relatively rare plant community.
Savannas are plant communities with a continuous grass layer and a scattered overstory of trees. Historically in the Midwest, savannas were a transition zone between prairies on the west and oak forests to the east. At the time of European settlement, there were 20 million hectares (approximately 50 million acres) of oak savanna. Less than 1% of the oak savanna remains; currently there are only about 12,000 hectares (approximately 30,000 acres) of savanna remaining.
Restoration of the Brookfield Oak Savanna
What is Restoration?
Ecological restoration is the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed.
Why Restore the Oak Savanna?
The Oak Savanna is a valuable resource for the residents of Brookfield; it provides a place within the village where people can interact with native plants and animals and get a taste of what the area was like pre-settlement. It also provides valuable habitat for wildlife and is a nice example of a relatively rare plant community. But like other natural areas in Chicagoland, it is negatively impacted by fragmentation, invasive plant species, and disruption of natural processes such as fire and grazing. By using common restoration methods, we can enhance the value of the savanna for both the people that visit and the plants and animals that live there.
The restoration process began in 2001 when mowing in the north part of Kiwanis Park ceased.
Prescribed Fire—Historically, fires occurred in oak savannas every 3–5 years. These fires maintained the open tree canopy and diverse grass and forb (flower) understory that is characteristic of savannas. In addition, fire released nutrients back into the soil and invigorated growth of native grasses and forbs. Naturally occurring fire is unlikely and undesirable given the isolated nature and location of the Brookfield Oak Savanna. Instead, prescribed fire is used to rejuvenate the understory and benefit native species.
Brush cutting—Invasive woody species such as buckthorn (Rhamnus catharticus), and Japanese honeysuckle (Lonicera japonica) are a major problem in savannas and forests in the Chicagoland area. They grow in dense thickets and choke out native vegetation. Some fast-growing native species such as boxelder (Acer negundo), green ash (Fraxinus pennsylvanica), silver maple (Acer saccarinum), cottonwood (Populus deltoides), Northern catalpa (Catalpa speciosa), and grey dogwood (Cornus racemosa) are thinned to reduce competition with and improve survival of the slower growing oak and hickory trees that are characteristic of Chicagoland savannas. The best method for dealing with these woody species is to cut them and apply herbicide to the cut stump.
Weed-pulling—Some invasive species such as garlic mustard (Alliaria petiolata) are effectively controlled by pulling them by hand.
Herbicide—Other invasive weeds such as burdock (Arctium minus), Canada thistle (Cirsium arvense), and bull thistle (Cirsium vulgare) resprout from taproots if pulled by hand and must be treated with herbicide for effective treatment.
Seed collecting and planting— Seeds are collected from plants within the Savanna and planted in other areas of the savanna to aid the natural spread of the plant species. However, some of the native plants that would have historically been found in an oak savanna are missing from Brookfield’s Oak Savanna, so seeds of these species are obtained from other nearby sites or from native plant nurseries and planted in the savanna as part of the restoration effort.
Other Activities of the Conservation Commission
The Conservation Commission hosts “Meet the Creek”, an annual celebration of our local water resource, Salt Creek.
This event varies somewhat each year, but typically includes Creek clean-up, educational activities, paddling information, and opportunities to take canoes out on the Creek.
Our Oak Savanna needs volunteers!
We meet periodically throughout the year to work on restoring the Oak Savanna. Work includes pulling weeds, cutting brush, planting and collecting seed. We also hold occasional special project days. No special knowledge is needed – we’ll provide the training and tools you need. All we ask is that you dress appropriately for conditions (long pants, socks, and closed shoes are a must year-round, and bring work gloves if you have them. Scheduled workdays will be posted here when known.
When and Where the Conservation Commission Meets
The Commission normally meets on the fourth Tuesday of the month in the Village Hall courtroom at 7:30 p.m., except in December and one or more summer months.
Members of the Conservation Commission include:
Bridget Jakubiak, Chair
For more information on local natural areas:
Chicago Wilderness (www.chicagowilderness.org)
Salt Creek (www.saltcreekwatershed.org)
Forest Preserve District of Cook County (www.fpdcc.com)
Des Plaines River Valley Restoration Volunteers (www.restoringnature.org)