This list of ecoregions in the United States provides an overview of United States ecoregions designated by the U.S. Environmental Protection Agency (EPA) and the Commission for Environmental Cooperation (CEC). The CEC was established in 1994 by the member states of Canada, Mexico, and the United States to address regional environmental concerns under the North American Agreement on Environmental Cooperation (NAAEC), the environmental side accord to the North American Free Trade Agreement (NAFTA). The Commission's 1997 report, Ecological Regions of North America, provides a framework that may be used by government agencies, non-governmental organizations, and academic researchers as a basis for risk analysis, resource management, and environmental study of the continent's ecosystems. In the United States, the EPA and the United States Geological Survey (USGS) are the principal federal agencies working with the CEC to define and map ecoregions. Ecoregions may be identified by similarities in geology, physiography, vegetation, climate, soils, land use, wildlife distributions, and hydrology.
The classification system has four levels, but only Levels I and III are shown on this list. Level I divides North America into 15 broad ecoregions; of these, 12 lie partly or wholly within the United States. Fifty Level II regions were created to allow for a narrower delineation of Level I areas. Three level I areas were not subdivided for level 2. Level III subdivides the continent into 182 smaller ecoregions; of these, 104 lie partly or wholly with the United States. Level IV is a further subdivision of Level III ecoregions. Level IV mapping is still underway but is complete across most of the United States. For an example of Level IV data, see List of ecoregions in Oregon and the associated articles. The classification system excludes the U.S. state of Hawaii, which is not part of the North American mainland.
The corresponding CEC ecoregion in Canada is called the Pacific Maritime Ecozone.
The corresponding CEC ecoregion in Canada is called the Montane Cordillera Ecozone.
The corresponding name in Canada for the same ecoregion is the Prairies Ecozone.
These forests stretch from the Southern Appalachians towards Canada, up to the northern Midwest. For a general description of these forests, refer to Temperate Deciduous Forest. The standard reference is The Deciduous Forest of Eastern North America. The adjoining forests in Canada are generally referred to as the Mixedwood Plains Ecozone or the Great Lakes-St.Lawrence Forest Region.
The Arizona/New Mexico Mountains ecoregion is a Level III ecoregion designated by the United States Environmental Protection Agency (EPA) in the U.S. states of Arizona and New Mexico.British Columbia Mainland Coastal Forests (WWF ecoregion)
British Columbia mainland coastal forests is a temperate coniferous forest ecoregion the Pacific coast of North America, as defined by the World Wildlife Fund (WWF) categorization system.Central Great Plains (ecoregion)
The Central Great Plains are a semi-arid 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.
It is designated as the Central and Southern Mixed Grasslands ecoregion by the World Wildlife Fund.Copper Plateau taiga
The Copper Plateau taiga is an ecoregion of North America, as defined by the World Wildlife Fund (WWF) categorization system and the Commission for Environmental Cooperation, in the Taiga and Boreal forests, Biome, Alaska.Edwards Plateau
The Edwards Plateau is a region of west-central Texas which 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 eastern portion of the plateau is known as the Texas Hill Country.High Plains (United States)
The High Plains are a subregion of the Great Plains mostly in the Western United States, but also partly in the Midwest states of Nebraska, Kansas, and South Dakota, generally encompassing the western part of the Great Plains before the region reaches the Rocky Mountains. The High Plains are located in southeastern Wyoming, southwestern South Dakota, western Nebraska, eastern Colorado, western Kansas, eastern New Mexico, western Oklahoma, and south of the Texas Panhandle. The southern region of the Western High Plains ecology region contains the geological formation known as Llano Estacado which can be seen from a short distance or on satellite maps. From east to west, the High Plains rise in elevation from around 1,160 feet (350 m) to over 7,800 feet (2,400 m).List of ecoregions in Illinois
The list of ecoregions in Illinois are lists of terrestrial ecoregions (see also, ecosystem) of the United States' State of Illinois, as defined separately by the United States Environmental Protection Agency (USEPA), and by the World Wildlife Fund. Illinois' ecology is in a land area of 56,400 square miles (146,000 km2); the state is 385 miles (620 km) long and 218 miles (351 km) wide and is located between latitude: 36.9540° to 42.4951° N, and longitude: 87.3840° to 91.4244° W, with primarily a humid continental climate.List of ecoregions in Indiana
The list of ecoregions in Indiana are listings of terrestrial ecoregions (see also, ecosystem) in the United States' State of Indiana, as defined separately by the United States Environmental Protection Agency (USEPA), and the World Wildlife Fund.List of ecoregions in Wisconsin
The list of ecoregions in Wisconsin are listings of terrestrial ecoregions (see also, ecosystem) in the United States' State of Wisconsin, as defined separately by the United States Environmental Protection Agency (USEPA), and the World Wildlife Fund.List of geographical regions in Texas
Texas is the second-largest state in the United States, with an area of 261,797 square miles (678,050 km2) and a population of 27.47 million in 254 counties. This covers an area 773 miles (1,244 km) wide by 790 miles (1,270 km) long. Due to its location and size, it is a part of a large number of unique geological regions, including the piney woods of East Texas, the plains in the Panhandle, the mountains in far West Texas, and hundreds of miles of coastline.
There are several different methods used to describe the geographic and geological differences within the state, and there are often subdivisions within a region which more accurately describe both the terrain and the culture. Because there is no single standard for subdividing the regions of Texas, many accepted areas either overlap or seem to contradict others. All are included for completeness.Lists of ecoregions
Wikipedia has articles relating to two separate ecoregion classification systems:
Ecoregions defined by the Commission for Environmental Cooperation and partner agencies in Canada, Mexico, and the United States:
List of ecoregions in North America (CEC)
List of ecoregions in the United States (EPA)
Ecoregions of the world defined by the conservation group World Wildlife Fund:
Global 200 ecoregions (WWF), 238 single or combined ecoregions identified by the World Wildlife Fund (WWF) as priorities for conservation.
List of terrestrial ecoregions (WWF) 867 terrestrial ecoregions.
List of marine ecoregions (WWF), 232 marine ecoregions of the coastal and continental shelf areas.
List of freshwater ecoregions (WWF), 426 freshwater ecoregions.
Lists of ecoregions by countryLists of ecoregions in the United States
Lists of ecoregions in the United States — based upon two separate ecoregion classification systems:
List of ecoregions in the United States (EPA) — United States Environmental Protection Agency system
List of ecoregions in the United States (WWF) — World Wildlife Fund systemNorthern Lakes and Forests (ecoregion)
The Northern Lakes and Forests are an ecoregion in northern Minnesota, northern Wisconsin, and northern Michigan in the United States. It is a Level III ecoregion in the United States Environmental Protection Agency's (EPA's) classification system, where it is designated as ecoregion number 50. The ecoregion is characterized by coniferous and northern hardwoods forests, morainal hills, large lake basins, and broad areas of sandy outwash plains, with numerous lakes and wetlands. The Northern Lakes and Forests are less well-suited to agriculture than ecoregions to the south, owing to shorter growing seasons, lower temperatures, and soils formed mainly from nutrient-poor sandy and loamy glacial drift material.Northern mixed grasslands
The Northern Mixed Grasslands is one of 867 terrestrial ecoregions defined by the World Wide Fund for Nature. This ecoregion includes parts of the Canadian provinces of Saskatchewan and Manitoba, north-central and eastern (except extreme eastern) North Dakota, most of east South Dakota, and small portions of western Minnesota in the American Great Plains. The United States Environmental Protection Agency (EPA) defines this ecoregion as the Northern Glaciated Plains.Sonoran Desert
The Sonoran Desert (Spanish: Desierto de Sonora) is a North American desert which covers large parts of the Southwestern United States in Arizona and California and of Northwestern Mexico in Sonora, Baja California, and Baja California Sur. It is the hottest desert in Mexico. It has an area of 260,000 square kilometers (100,000 sq mi). The western portion of the United States–Mexico border passes through the Sonoran Desert.
In phytogeography, the Sonoran Desert is within the Sonoran Floristic Province of the Madrean Region in southwestern North America, part of the Holarctic Kingdom of the northern Western Hemisphere. The desert contains a variety of unique and endemic plants and animals, such as the saguaro (Carnegiea gigantea) and organ pipe cactus (Stenocereus thurberi).Southeastern Wisconsin Till Plains (ecoregion)
The Southeastern Wisconsin Till Plains is an ecoregion in southeastern Wisconsin and northeastern Illinois in the United States. It is a Level III ecoregion in the classification system of the United States Environmental Protection Agency (EPA), where it is designated as ecoregion number 53. The ecoregion represents a transition between the hardwood forests and oak savannas to the west and the tallgrass prairie ecoregions to the south; it is today mostly covered by cropland.Southwestern Tablelands
The southwestern tablelands is an ecoregion running from east-central to south-east Colorado, east-central and a small portion of east New Mexico, some eastern portions of the Oklahoma Panhandle, far south-central Kansas and portions of northwest Texas. This ecoregion has a "cold semi-arid" climate (Köppen BSk). Some years, a National Weather Service warning is issued in parts of Texas due to a dust storm originating from the lower part of the Southwestern Tablelands ecological region or from the southern end of the Western High Plains ecological region.Tallgrass prairie
The tallgrass prairie is an ecosystem native to central North America. Natural and anthropogenic fire, as well as grazing by large mammals (primarily bison), were historically agents of periodic disturbance, which regulates tree encroachment, recycles nutrients to the soil, and catalyzes some seed dispersal and germination processes. Prior to widespread use of the steel plow, which enabled conversion to agricultural land use, tallgrass prairies expanded 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.
They were characteristically found in the central forest-grasslands transition, the central tall grasslands, the upper Midwest forest-savanna transition, and the northern tall grasslands ecoregions. They flourished in areas with rich loess soils and moderate rainfall around 30-35 inches (700–900 mm) per year. To the east were the fire-maintained eastern savannas. In the northeast, where fire was infrequent and periodic windthrow represented the main source of disturbance, beech-maple forests dominated. In contrast, shortgrass prairie was typical in the western Great Plains, where rainfall is less frequent and soils are less fertile. Due to expansive agricultural land use, very little tallgrass prairie remains.Western Allegheny Plateau (ecoregion)
The Western Allegheny Plateau is an ecoregion of the Temperate broadleaf and mixed forests Biome, located on the western Allegheny Plateau and in the Appalachia region of the Eastern United States.