Native tallgrass prairie is one the rarest and most endangered ecosystems in the world. Less than 1% of original tallgrass prairie still exists. A typical tallgrass prairie is a mixture of grasses and forbs (flowers). Grasses make up the bulk of plants growing on a prairie while forbs contribute to the diversity. There are six types of prairie in Illinois: black soil, sand, gravel, dolomite, hill prairie, and shrub prairie.
All prairie plants have one thing in common, deep roots. It takes the average prairie plant two to three years to bloom from seed. Plants put great energy into growing roots, often before producing flowers and height. Prairie plants are akin to icebergs. While the plants on the surface appear quite large, 70% of the average prairie plant is found below ground. The eloquence of this root adaptation allows prairie plants to withstand extreme environmental conditions occurring on prairies.
Deep roots increase plant survival of harsh environmental conditions. Extensive root systems, 16 feet or more, create a vast underground storage system for water and food. When nature brings extreme high and low temperatures, drought or flooding, excessive grazing by animals and insects, and fire burning all above ground plant growth, prairie still rebounds. The adaptation of extensive roots provides food and water prairie plants need to survive and thrive.
Deep rooted prairie plants provide important ecosystem services for us. Prairie plants help provide better rainfall and runoff infiltration of water into soil. One acre of established prairie can produce 24,000 lbs. of roots which can absorb 9 inches of rainfall per hour before runoff occurs. Intense rain episodes can be eased by prairie roots. An acre of established prairie will intercept as much as 3 tons of water during a one inch per hour rain event. Underground aquifers can be refilled. Roots open pores into soil and allow water to percolate deeply to fill aquifers and reduce standing water. Prairies and their deep roots deserve a place in our landscape for the beauty as well as the vital services they perform.