The tallgrass prairie is an ecosystem native to central North America. Historically, natural and anthropogenic fire, as well as grazing by large mammals provided periodic disturbances to these ecosystems, limiting the encroachment of trees, recycling soil nutrients, and facilitating seed dispersal and germination. Prior to widespread use of the steel plow, which enabled large scale conversion to agricultural land use, tallgrass prairies extended throughout the American Midwest and smaller portions of southern central Canada, from the transitional ecotones out of eastern North American forests, west to a climatic threshold based on precipitation and soils, to the southern reaches of the Flint Hills in Oklahoma, to a transition into forest in Manitoba.
Flowering big bluestem, a characteristic tallgrass prairie plant
Bison grazing on the 158 km2 (39,000-acre) Tallgrass Prairie Nature Preserve in Osage County, Oklahoma
A pink wild onion (Allium stellatum) — blooms in the tallgrass prairie of Waubay Wetland Management District in South Dakota.
Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type. Temperate grassland regions include the Pampas of Argentina, Brazil and Uruguay, and the steppe of Ukraine, Russia and Kazakhstan. Lands typically referred to as "prairie" tend to be in North America. The term encompasses the area referred to as the Interior Lowlands of Canada, the United States, and Mexico, which includes all of the Great Plains as well as the wetter, hillier land to the east.
Tallgrass prairie flora (Midewin National Tallgrass Prairie)
Prairie grasses
Wheatfield intersection in the Southern Saskatchewan prairies, Canada.
Prairie Homestead, Milepost 213 on I-29, South Dakota (May 2010)