• Mississippi National River and Recreation Area

    Mississippi

    National River & Recreation Area Minnesota

About Prairies

What is a Prairie?

When European settlers came to North America, they encountered vast expanses of grass and wildflowers. They named these golden seas of remarkable beauty "prairies" for the French word for meadow. A prairie is a treeless landscape dominated by grasses and wildflowers (forbs). Complex and very productive ecosystems, the prairies of North America once covered a large portion of the continent, ranging from the Rocky Mountains in the west and continuing into Illinois and Indiana in the east, and extending from Canada in the north to Texas in the south. Today, less than 1% of the prairie remains, mostly in small patches. Restoration sites, steep river banks, roadsides and small pieces of land that were never cultivated are areas where prairie remnants are found today. Check out prairies in Minnesota.

What Types are There?

Three types of prairie exist in North America; short, mixed and tallgrass prairie. As the prairie moves from west to east, precipitation levels increase, and the prairie plants show a corresponding pattern of increased height.

  • The shortgrass prairie begins east of the Rocky Mountains where the climate is hot and dry due to the rain shadow created by the mountains.

  • The tallgrass prairie, also called the true prairie, is the easternmost prairie in the United States, extending north into Minnesota and east into Indiana, where the climate is relatively wetter.

  • The mixed prairie is an intermediate type between the short and tallgrass prairies, and has characteristics of both types. Shortgrass prairies are dominated by bunchgrasses, such as Little Blue Stem (Schizachyrium scoparium).

  • Bunchgrasses are shorter than other grasses, and grow in clumps. They prefer the drier climates of the shortgrass prairie, and are found in dry areas of tallgrass prairies.Schizachyrium scoparium is the dominant bunchgrass.

  • Sodgrasses, such as Big Blue Stem (Andropogon gerardii) and Indian Grass (Sorghastrum nutans) dominate Tallgrass prairies. Sod grasses spread horizontally and prefer wetter climates.


Although different types of grasses characterize the short and tallgrass prairies, any prairie is a mixture of many microclimates that have different types of plants in them. The tallgrass prairie, although characterized by a certain type of grass, also has bunchgrasses and shortgrass prairie forbs.

  • Prairie grasses and forbs have evolved adaptations to withstand the harsh climate they live in.

  • They must be able to survive long, cold winters and hot, harsh summers with strong wind and high light intensity, as well as fire and grazing.

  • The leaves may be finely divided or narrow in order to prevent drying out from exposure to the sun and to lessen wind resistance.

  • Many leaves have hairy surfaces to deflect sunlight and wind, or they have leathery or waxy leaves to prevent water loss.

  • Prairie plants have extensive root systems that allow them to absorb water in times of drought.

  • Their buds are at or below the ground, allowing them to survive fire.
 
Native Minnesota Prairie
What Happened to the Prairies of North America?

Prairies need disturbances such as drought, fire and grazing to survive. They rely on these things to keep woody plants from invading the prairie and turning it into a forest. In pre-settlement times, enormous herds of grazers, such as bison, roamed the Plains, and their impacts helped to create the diversity that is essential to the prairie’s health. Grazers, through their browsing, wallowing (depressions where they lay), and fertilizing help to create a patchy landscape that promotes the growth of different kinds of plants. Drought is also important because prairie plants are much better adapted to survive dry conditions than trees, so droughts give the grasses and forbs a competitive advantage. Fire is extremely important in maintaining the health and diversity of the prairie while keeping the woody plants from establishing themselves. Before European settlers came to the Great Plains, fire was a relatively common phenomenon, coming both from natural sources such as lightening strikes, and from Native Americans. Native Americans used fire for a variety of reasons, including its use in controlling grazers. When a prairie is burned, the regrowth is very luxurious, so the bison would be attracted to it, and the Native Americans could have a better chance of hunting them.

When settlers came, they realized that the tallgrass prairie has some of the most fertile soil in the world, and cultivated the land. As a result, much of the prairie became farmland. If an area was too wet or too dry to be cultivated, it was either overgrazed or became a woodland community due to the suppression of fire. Development of the fertile prairie lands into farmlands and later urban area has also hurt the prairie ecosystem. Another impact the settlers had on the prairie was the introduction of exotic species, which can often outcompete native species because they begin their growing season sooner in the year and they don’t have their natural competitors to keep their populations low. Exotic species are still a major problem for prairie restoration today.

Did You Know?

Headwaters of the Mississippi

The Mississippi River is approximately three feet deep at its headwaters at Lake Itasca and has an average surface speed of 1.2 miles per hour.