Prairie’s place in modern Illinois

By Duane Friend

Picture yourself in what was to become Illinois in the early 1800s. What would you have seen? If you were in central or northern Illinois, you would have seen mostly prairie. Twenty million acres of prairie covered the northern two thirds of the state.

Prairies varied according to the wetness of soil. Wet, dry and mesic (in between) locations could be found across the landscape, each area containing native plants, which were adapted to the specific moisture conditions present in each location. Not only were tall grasses like Big Bluestem present, there were many types of flowering plants, flowering from late spring to late summer.

Prairie plants have very large and deep root systems, some reaching down to 15 feet below the soil surface. These massive root systems created huge amounts of organic matter, leading to the very productive soils we have today in the Midwest.

Fire was a big player in keeping prairies in place. If no fires had occurred, shrubs and trees would have taken over.

“The uniformly rich soil of the Illinois and Wisconsin prairies produced such a close and tall growth of grasses that no tree could live on it. Had there been no fires, these fine prairies, so marked a feature of the country, would have been covered by the heaviest forest.”

– from Aldo Leopold’s “A Sand County Almanac and Sketches Here and There.”

Fires occurred from lightning strikes, or were started by humans. Native Americans are likely to have used small burns to manage wildlife locations and to provide a lush food source for bison.

We can still see this type of ecosystem in Illinois. If you look closely, you can see some areas that are being converted back to prairie, with the help of federal conservation programs.

The photo shown is from my family farm. It had been farmed as cropland and a pasture for well over 150 years. The photo shows what the farm looks like three years after being planted with native prairie species, which is about the time it takes for prairie plants to become well established after seeding. The soil here is sandy and prone to drought, but also has a water table that can produce standing water on fields periodically. The seeding for this type of area has to be adapted to both droughty and wet conditions.

Many of these small pockets of prairie will need to have periodic controlled burns to keep out shrubs and trees. Prairie burns can be exciting to see, but they must be managed by professionally trained burn teams and coordinated by an experienced burn manager. Large fields must be divided into small burn units, with units being burned every three to five years.

Another benefit of flowering prairies is the attraction of pollinators. Numerous plants, which are flowering at different times of summer, providing a consistent source of food for these pollinators. This is great habitat for bees and butterflies which are needed to pollinate many Illinois crops. These prairie pockets can show Illinois as it was, and help Illinois soils and crops in the present.

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About the author

Duane is an Educator with University of Illinois Extension in the Calhoun/Cass/Greene/Morgan/Scott unit.

View all articles by Duane Friend