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Flint Hills tall grasslands

The Flint Hills Tall Grasslands covers the Flint Hills of Kansas and the Osage Plains of northeastern Oklahoma. The Flint Hills Tall Grasslands is the smallest grassland ecoregion in North America. It can be distinguished from other grassland associations by the dominance of tallgrass species–and from the Central Tall Grasslands to the north by its more depauperate biota and a thin soil layer spread over distinct beds of limestone. These flinty beds of limestone, from which the name of this ecoregion is derived, rendered large areas unsuitable for corn or wheat farming. Today, the Flint Hills Tall Grasslands is an anomaly–an essentially unplowed (although heavily grazed) remnant of the tallgrass prairie. Historically, fire, drought and grazing by bison (Bison bison) and other ungulates were the principle sources of habitat disturbance in this ecoregion. A new tallgrass prairie national park has been established covering about 44 km2. This ecoregion offers the best opportunity for restoration of tallgrass prairie in the United States (Madson 1993).

  • Scientific Code
  • Ecoregion Category
  • Size
    11,400 square miles
  • Status
  • Habitats

Biological Distinctiveness
The Flint Hills and adjacent Osage Hills contain the last large pieces of tallgrass prairie in the world. The Flint Hills is less rich in species than the Central Tall Grasslands. The dominant grass species in this ecoregion are big bluestem (Andropogon gerardii), switchgrass (Panicum virgatum), and Indian grass (Sorghastrum nutans) (Küchler 1975). Like other ecoregions of this section of North America, bison and elk (Cervus elaphus) once roamed these tallgrass prairies, where they were hunted by the prairie wolf (Canis lupus). These species are now gone, although bison are being reestablished in this ecoregion. Greater prairie chicken (Tympanuchus cupido) are common on the Tallgrass Prairie Reserve.

Conservation Status

Habitat Loss and Degradation
Much of the Flint Hills and the Osage Hills are in relatively good condition. Although grazed by livestock, native common plant species still occur.

Remaining Blocks of Intact Habitat
This unit contains the largest blocks of "relatively intact" tallgrass prairie among the three tallgrass units and some of the largest blocks in all of the Great Plains ecoregions.

Several important blocks of habitat in this ecoregion include:

•The Barnard Ranch (TNC-owned ranch in Osage Hills) - northeastern Oklahoma
•Tallgrass Prairie National Preserve, Flint Hills region - central Kansas - approximately 44 km2
•Konza Prairie - northeastern Kansas (important research site for tallgrass prairie ecosystem) - 34.8 km2
Degree of Fragmentation
Habitat fragmentation is relatively low considering existing land use and level of grazing.

Degree of Protection
The creation of the Tallgrass Prairie National Park in 1996 adds to the amount of habitat protected in this unit. The Nature Conservancy has also established a large conservation unit in the Osage Hills (Barnard Ranch).

Types and Severity of Threats
Because this ecoregion is too difficult to farm, future threats of conversion to agriculture remain low relative to other grassland ecoregions. Grazing could become a more severe threat if not properly managed. Some rangeland has been converted to non-native cool-season grass. There is increasing fragmentation due to smaller homestead units being incorporated? into large ranches.

Suite of Priority Activities to Enhance Biodiversity Conservation

•Working with appropriate agencies, efforts should be made to increase protection of the Flint and Osage hills.
•Additional activities of high priority are to reconnect and restore the remaining blocks of habitat. This will be an uphill effort in most areas and perhaps futile in others. The extent of habitat conversion of this ecoregion is discouraging and support for conservation is weak in parts of this unit.
•It is important to alter range practices to manage for biodiversity value rather than maximum beef production.
Conservation Partners

•Dr. Clinton Owensby- world authority on the Tall Grass Prairie
•Kansas Natural Heritage Inventory
•The Nature Conservancy, Tallgrass Prairie Office
•U.S. Fish and Wildlife Service
Relationship to other classification schemes
Tallgrass prairie is derived from Sims (1988). It corresponds to Omernik (1995) ecoregion 28 (Flint Hills) and Bailey (1994) section 251F (Flint Hills).

Prepared by: S. Chaplin, P. Simms, T. Cook, E. Dinerstein