Tallgrass Prairie - Code: Ne7B

The tallgrass prairie is a dense and towering grassland habitat that historically stretched from Oklahoma in the sc. United States to Manitoba, Canada; it is the great Nearctic grassland of the e. Great Plains. A few tall species of grass dominate, producing 80% of the biomass, while a diverse array of flowering plants makes up the remaining 20% of the prairie flora. While generally cooler and wetter than the shortgrass prairie to its west, this habitat has such a broad latitudinal spread that it experiences a massive range of temperatures, from ⎻31°F (⎻35°C) to 80°F (27°C) in the north, and 22°F (⎻5°C) to over 110°F (44°C) in the south. Despite these extremes, the region is overall temperate and receives a moderate amount of rainfall, 20–40 in. (500–1,000mm) annually, concentrated in intense storms in spring and early summer.
 
Known as “the four horsemen of the prairie,” Big Bluestem (Andropogon gerardii), Switchgrass (Panicum virgatum), Indiangrass (Sorghastrum nutans), and Little Bluestem (Schizachyrium scoparium) are the core species of this habitat. These grasses are generally 2–3 ft. (0.6–0.9m) in height, though at the end of the growing season healthy prairies are often 5-6 ft (1.8m) in height and  some can reach 10 ft. (3m). In late summer it is easy to disappear in the Tallgrass Prairie and visibility can be nil. Growing among these core species of grass is a bountiful collection of wildflowers, including Annual Sunflower (Helianthus annuus), Leadplant (Amorpha canescens), Scurfpea (Psoralidium spp.), Purple Coneflower (Echinacea purpurea), milk vetches (Astragalus spp.), blazingstars (Liatris spp.), and Heath Aster (Aster ericoides), that transform the prairies into colorful patchworks during the spring and summer months. Historically rare away from permanent water, woody plants like Eastern Red Cedar (Juniperus virginian), Buckbrush (Ceanothus spp.), Bur Oak (Quercus macrophylla), Common Hackberry (Celtis occidentalis), Plains Cottonwood (Populus deltoides), and Eastern Redbud (Cercis canadensis) have encroached as fire regimes have changed.
 There are many smaller grassland subtypes that we have chosen to include under the umbrella of Tallgrass Prairie. While generally smaller, and more isolated than the principal Tallgrass Prairie, these grasslands share many of the same characteristic plants and wildlife.
 Eastern Oak Savannas occur in transitional zones between Nearctic Temperate Deciduous Forest and Tallgrass Prairie. These open savannas have an understory dominated by Tallgrass Prairie grasses and forbs with an overstory largely consisting of Bur Oak (Quercus macrocarpa), Northern Pin Oak (Quercus ellipsoidalis), and Black Oak (Quercus velutina). Historically these habitats were maintained by fire and rarely had canopy cover greater than 25%. 
The Florida Dry Prairie is a very rare grassland found on the Florida peninsula. Once the dominant habitat in central Florida this habitat is all but gone. Frequent spring fires and summer flooding prevented the growth of Eastern Pine Savannas. The habitat is shrubbier than most Tallgrass Prairies with Saw Palmetto (Serenoa repens) being a common element along with wiregrass (Aristidia beyrichiana), Little Bluestem (Schizachyrium scoparium), toothache grass (Ctenium aromaticum), Lopsided Indiangrass (Sorghastrum secundum), and Splitbeard Bluestem (Andropogon ternarius).
The Gulf Coast Prairie is the most extensive of these subtypes, extending along the coastal plain from Mississippi to Tamaulipas in Mexico. Gulf Coast Prairies are dominated by the big four Tallgrass Prairie grasses along with Brownseed Paspalum (Paspalum plicatulum) and Savanna Hairgrass (Muhlenbergia expansa). These prairies are wetter than most Tallgrass subtypes and tree growth is restricted mostly by the dominance of dense clay soils. This habitat subtype is frequently interspersed with Nearctic Saltmarsh and Nearctic Sedge and Grassland Marshes.
 The Prairie Potholes (Sidebox X) is a region of Tallgrass and Mixed Grass Prairie dotted with a high density of small freshwater wetlands.
 The tallgrass prairie was formerly subjected to sweeping disturbance that regularly cleansed the area and prevented the encroachment of trees. Rapid fires would tear through the grasses, recycling nutrients and renewing the habitat. The large herds of American Bison that once grazed here provided more localized disturbance and variation in vegetation height. Efforts are being made in remaining tallgrass prairie sites to restore and maintain these historical methods of disturbance, with regular burns occurring at most locations and active reintroduction of bison to larger tracts of protected land.