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.
The Edwards Plateau is a geographic region forming the crossroads of Central, South and West Texas, United States. It is named in honor of Haden Edwards. It is bounded by the Balcones Fault to the south and east; the Llano Uplift and the Llano Estacado to the north; and the Pecos River and Chihuahuan Desert to the west. San Angelo, Austin, San Antonio and Del Rio roughly outline the area. The plateau, especially its southeast portion, is also known as the Texas Hill Country.
The Piney Woods is a temperate coniferous forest terrestrial ecoregion in the Southern United States covering 54,400 square miles (141,000 km2) of East Texas, southern Arkansas, western Louisiana, and southeastern Oklahoma. These coniferous forests are dominated by several species of pine as well as hardwoods including hickory and oak. Historically the most dense part of this forest region was the Big Thicket though the lumber industry dramatically reduced the forest concentration in this area and throughout the Piney Woods during the 19th and 20th centuries. The World Wide Fund for Nature considers the Piney Woods to be one of the critically endangered ecoregions of the United States. The United States Environmental Protection Agency (EPA) defines most of this ecoregion as the South Central Plains.
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.
An oak savanna is a type of savanna—or lightly forested grassland—where oaks are the dominant trees. The terms "oakery" or "woodlands" are also used commonly, though the former is more prevalent when referencing the Mediterranean area. These savannas were maintained historically through wildfires set by lightning, humans, grazing, low precipitation, and/or poor soil.
The Big Thicket is the name given to a somewhat imprecise region of a heavily forested area of Southeast Texas in the United States. This area represents a portion of the mixed pine-hardwood forests or "Piney Woods" of the Southeast US. The National Park Service established the Big Thicket National Preserve (BTNP) within the region in 1974 and it is recognized as a biosphere reserve by UNESCO. Although the diversity of animals in the area is high for a temperate zone with over 500 vertebrates, it is the complex mosaic of ecosystems and plant diversity that is particularly remarkable. Biologists have identified at least eight, and up to eleven, ecosystems in the Big Thicket area. More than 160 species of trees and shrubs, 800 herbs and vines, and 340 types of grasses are known to occur in the Big Thicket, and estimates as high as over 1000 flowering plant species and 200 trees and shrubs have been made, plus ferns, carnivorous plants, and more. The Big Thicket has historically been the most dense forest region in what is now Texas.
The Texas Blackland Prairies are a temperate grassland ecoregion located in Texas that runs roughly 300 miles (480 km) from the Red River in North Texas to San Antonio in the south. The prairie was named after its rich, dark soil. Less than 1% of the original Blackland prairie vegetation remains, scattered across Texas in parcels.
The Western Gulf coastal grasslands are a subtropical grassland ecoregion of the southern United States and northeastern Mexico. It is known in Louisiana as the "Cajun Prairie", Texas as "Coastal Prairie," and as the Tamaulipan pastizal in Mexico.
The Osage Plains are a physiographic section of the larger Central Lowland province, which in turn is part of the larger Interior Plains physiographic division. The area is sometimes called the Lower Plains, North Central Plains,or Rolling Plains. The Osage Plains, covering west-central Missouri, the southeastern third of Kansas, most of central Oklahoma, and extending into north-central Texas, is the southernmost of three tallgrass prairie physiographic areas. It grades into savanna and woodland to the east and south, and into shorter, mixed-grass prairie to the west. The Osage Plains consist of three subregions. The Osage Plains proper occupy the northeast segment. Although sharply demarcated from the Ozark uplift, the plains are nonetheless a transitional area across which the boundary between prairie and woodland has shifted over time. In the central portion of the physiographic area lies the second subregion, the Flint Hills, commonly called "the Osage" in Oklahoma. This large remnant core of native tallgrass prairie is a rocky rolling terrain that runs from north to south across Kansas and extends into Oklahoma. To the west and south of these hills are the Blackland Prairies and Cross Timbers. This vegetatively complex region of intermixed prairie and scrubby juniper-mesquite woodland extends into north-central Texas. Bluestem prairies and oak-dominated savannas and woodlands characterize the natural vegetation in the Cross Timbers. Much of the area has been converted to agriculture, although expanses of oak forest and woodland are still scattered throughout the eastern portion of the subregion.
The Willamette Valley ecoregion is a Level III ecoregion designated by the United States Environmental Protection Agency in the U.S. states of Oregon and Washington. Slightly larger than the Willamette Valley for which it is named, the ecoregion contains fluvial terraces and floodplains of the Willamette River system, scattered hills, buttes, and adjacent foothills. It is distinguished from the neighboring Coast Range, Cascades, and Klamath Mountains ecoregions by lower precipitation, lower elevation, less relief, and a different mosaic of vegetation. Mean annual rainfall is 37 to 60 inches, and summers are generally dry. Historically, the region was covered by rolling prairies, oak savanna, coniferous forests, extensive wetlands, and deciduous riparian forests. Today, it contains the bulk of Oregon's population, industry, commerce, and agriculture. Productive soils and a temperate climate make it one of the most important agricultural areas in Oregon.
The Klamath Mountains ecoregion of Oregon and California lies inland and north of the Coast Range ecoregion, extending from the Umpqua River in the north to the Sacramento Valley in the south. It encompasses the highly dissected ridges, foothills, and valleys of the Klamath and Siskiyou Mountains. It corresponds to the Level III ecoregion designated by the Environmental Protection Agency and to the Klamath-Siskiyou forests ecoregion designated by the World Wide Fund for Nature.
The eastern woodlands of the United States covered large portions of the southeast side of the continent until the early 20th century. These were in a fire ecology of open grassland and forests with low ground cover of herbs and grasses.
The Ozark Highlands is a Level III ecoregion designated by the Environmental Protection Agency (EPA) in four U.S. states. Most of the region is within Missouri, with a part in Arkansas and small sections in Oklahoma and Kansas. It is the largest subdivision of the region known as the Ozark Mountains, less rugged in comparison to the Boston Mountains in Arkansas, the highest part of the Ozarks.
The central forest–grasslands transition is a prairie ecoregion of the central United States, an ecotone between eastern forests and the North American Great Plains. It is a classification defined by the World Wildlife Fund.
The Interior Low Plateaus are a physiographic region in eastern United States. It consists of a diverse landscape that extends from north Alabama across central Tennessee and Kentucky into southern Illinois, Indiana, and Ohio. Its natural communities are a matrix of temperate forests, woodlands, and prairies.
The Central Great Plains are a semiarid prairie ecoregion of the central United States, part of North American Great Plains. The region runs from west-central Texas through west-central Oklahoma, central Kansas, and south-central Nebraska.
The Canadian Aspen Forests and Parklands is one of 844 terrestrial ecoregions defined by One Earth. This ecoregion includes parts of the Canadian provinces of Alberta, Saskatchewan, and Manitoba, north-central and eastern North Dakota, most of east South Dakota, and north-central Nebraska in the American Great Plains. The United States Environmental Protection Agency (EPA) defines this ecoregion as the Northern Glaciated Plains.
The Mississippi Alluvial Plain is a Level III ecoregion designated by the Environmental Protection Agency (EPA) in seven U.S. states, though predominantly in Arkansas, Louisiana, and Mississippi. It parallels the Mississippi River from the Midwestern United States to the Gulf of Mexico.
The Arkansas Valley is a Level III ecoregion designated by the Environmental Protection Agency (EPA) in the U.S. states of Arkansas and Oklahoma. It parallels the Arkansas River between the flat plains of western Oklahoma and the Arkansas Delta, dividing the Ozarks and the Ouachita Mountains with the broad valleys created by the river's floodplain, occasionally interrupted by low hills, scattered ridges, and mountains. In Arkansas, the region is often known as the Arkansas River Valley, especially when describing the history and culture of the region.
The Western Corn Belt Plains is a Level III ecoregion designated by the Environmental Protection Agency (EPA) in seven U.S. states, though predominantly in Iowa.
