Chicago Botanic Garden

Prairie Ecosystems

Illinois is known as the “prairie state,” yet less than one-tenth of one percent of original prairie remains. The Chicago Botanic Garden’s Suzanne B. Dixon Prairie was established so visitors could learn about the diversity of prairies in the Chicago region. Soil disturbance in the prairie can affect our ability to create or restore our historic native grasslands. Since soil disturbance is an ever-increasing factor in the Chicago region and beyond, much needs to be learned about how these disruptions can affect soil’s ability to support a diverse and sustainable native grassland community. Understanding soil disturbances will help scientists preserve regional biodiversity and develop alternatives for sustainable landscaping.

Our area is rich in plant diversity thanks to ancient glaciers that left a variety of soils and landforms supporting different types of prairies. The Dixon Prairie features re-creations of these prairie communities in a 15-acre exhibit with interpretive programs and descriptive signage. Included are mesic (moist), wet, gravel hill, fen and sand prairies as well as a burr oak savanna and sedge meadow. These communities support more than 250 species of prairie plants.

PHOTO: prairie burn The diversity of prairie in the Midwest could not exist without fire, which prevents trees and shrubs from encroaching and shading out the prairie. At Dixon Prairie, controlled burns help suppress the invasion of woody and herbaceous weeds, while encouraging fire-tolerant prairie species to flourish. 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 re-created landscapes is a research priority for the Garden. For example, prairie plants have evolved to tolerate grazing by animals both large (bison and deer) and small (voles and rabbits). However, researchers at the Garden have found that these same plants, when restored to areas with highly disturbed soils, are either unable to survive similar levels of grazing, or perhaps even attract more grazers. This is limiting long-term restoration success on some soils, as key prairie plants aren’t able to survive over multiple seasons of grazing. The goal of prairie restoration work at the Garden and across the Midwest is to understand these relationships and find solutions to promote the long-term sustainability of grassland restorations and creations.