The Butler University Prairie was established in 1987 by the Holcomb Research Institute and Butler University. Located between the Indianapolis Water Company Canal and the White River, the 4-acre prairie serves as an outdoor laboratory for Butler ecology courses, as a public educational resource, and as a natural area for birds and wildlife. A flier describing the prairie, including flowering dates of its species, is available.
What is a Prairie?
A prairie is a native plant community dominated by grasses. Other non-woody flowering plants called “forbs” also grow in prairies. Prairies originally covered a large area of North America, forming a triangle that stretched from Saskatchewan to Texas and eastward to central Ohio. In the west, prairies are dominated by short grasses only a few feet tall, while in the Midwest the tallgrass prairies are dominated by grasses that may reach nine feet. Because most prairies have deep, rich soil, vast areas of prairie have been converted to agricultural land.
At one time prairies covered 15 percent of Indiana, mainly in the west central and northwest portion of the state. Less than 1 percent of this area remains, with the rest of the prairie lost to development or agriculture. While a few large prairies in Indiana have been preserved, most of those remaining are small remnants found in areas left unplowed or undeveloped, as within cemeteries or along railroad tracks.
Prairies are divided into different types based on the amount of soil moisture available to the plants. Dry, mesic (or “medium”), and wet prairies all occur in Indiana. Each of these prairie types has its own group of plant species adapted to those particular moisture conditions.
Prairies and Fire
Old fields no longer under cultivation eventually become covered by herbs, shrubs, and finally by forest. This is the process of “succession,” or the change over time of the plant communities occupying a site. Given that Indiana has a moist climate suitable for forest, why is it that Indiana prairies do not eventually succeed into forests? The answer is fire.
The Role of Fire
Before European settlement, autumn and spring fires set both by lightning and native Americans raced through prairies. Such fires kill most trees, bu not the grasses and forbs. Prairie plants are not killed by fires because they store food in their massive root systems each autumn, and so survive even though all the above-ground parts burn. Most prairie plants have root systems twice as deep as the stem is tall – impressive when you consider that some of these grasses are nine feet tall!
After European settlement, fire frequencies were reduced, allowing trees to invade grasslands in many eastern parts of the prairie region. Many woody species have invaded the Butler prairie, including cottonwood, Siberian elm, trumpet creeper, box elder, and elderberry. In order to keep Butler prairie from becoming “Butler Forest” it will be burned each year when conditions permit careful control of the fire.