Ecoregions of the United States

Ecoregions of the United States
Name	Ecoregions of the United States
Country	United States

Ecoregions of the United States describe spatial units defined by recurring patterns of climate (forbidden), soils (forbidden), vegetation (forbidden). They are used for conservation planning by agencies such as the Environmental Protection Agency, the United States Geological Survey, the Nature Conservancy, the World Wildlife Fund, and the National Park Service. Classification schemes link regional planning with international frameworks like the International Union for Conservation of Nature and programs such as the Convention on Biological Diversity and the United Nations Environment Programme.

Overview and Classification

Ecoregions are hierarchical frameworks developed through collaboration among entities including the Environmental Protection Agency, the United States Geological Survey, the North American Commission for Environmental Cooperation, and the National Oceanic and Atmospheric Administration. The primary U.S. schemes—EPA Level I–III and the USGS ecoregion mapping—are coordinated with continental maps used by the Commission for Environmental Cooperation and referenced in reports by the Smithsonian Institution and the National Academies of Sciences, Engineering, and Medicine. Historical influences include mapping efforts by the U.S. Forest Service and regional inventories from the Fish and Wildlife Service and the Bureau of Land Management.

Major Ecoregion Types and Zones

Major terrestrial ecoregion types include temperate broadleaf and mixed forests represented in the Appalachian Mountains, temperate coniferous forests in the Pacific Northwest, tropical and subtropical moist broadleaf forests in Hawaii and parts of Puerto Rico, and temperate grasslands represented by the Great Plains. Other notable zones are Mediterranean forests in the California Floristic Province, deserts in the Mojave Desert and Sonoran Desert, and boreal forests and tundra in Alaska. Coastal and marine ecoregions include the Gulf of Mexico, the North Atlantic Ocean, the Pacific Ocean seaboard, and insular zones around the Aleutian Islands and the Mariana Islands.

Regional Ecoregions by State and Territory

State- and territory-level ecoregion delineations inform management in jurisdictions such as California, Texas, Florida, Alaska, Hawaii, Arizona, New Mexico, Oregon, Washington (state), Montana, Wyoming, Colorado, Idaho, Nevada, Utah, North Carolina, South Carolina, Georgia (U.S. state), Virginia, Pennsylvania, New York (state), Maine, Minnesota, Wisconsin, Michigan, Ohio, Kentucky, Tennessee, Missouri, Arkansas, Louisiana, Mississippi, Alabama, Indiana, Illinois, Iowa, Nebraska, Kansas, Oklahoma, North Dakota, South Dakota, Vermont, New Hampshire, Massachusetts, Rhode Island, Connecticut, New Jersey, Delaware, Maryland, West Virginia, Oregon, Washington, D.C., and territories including Puerto Rico, U.S. Virgin Islands, Guam, and American Samoa. Regional analyses draw on datasets produced by institutions such as the State University of New York, the University of California, the University of Alaska Fairbanks, the University of Hawaii, and state departments like the California Department of Fish and Wildlife.

Biodiversity and Ecosystem Services

Ecoregions underpin assessments of species distributions used by the U.S. Fish and Wildlife Service, the National Marine Fisheries Service, the Smithsonian Institution, the American Museum of Natural History, and the Brookings Institution for policy-relevant studies. Key biodiversity centers include the Appalachian Mountains for salamanders, the California Floristic Province for endemic plants, the Mississippi River Alluvial Plain for migratory birds associated with the Audubon Society, and the Everglades for unique hydrologic-dependent assemblages studied by the Everglades National Park and the South Florida Water Management District. Ecosystem services—such as water purification in the Chesapeake Bay watershed, carbon storage in the Tongass National Forest, pollination services relevant to the United States Department of Agriculture, and coastal storm buffering in the Gulf Coast—are mapped and valued by entities including the Natural Resources Defense Council and the World Resources Institute.

Threats and Conservation Efforts

Major threats vary among ecoregions: habitat loss in the California Central Valley, invasive species in the Great Lakes as tracked by the Great Lakes Commission, altered fire regimes in the Sierra Nevada and Interior West monitored by the National Interagency Fire Center, sea-level rise impacts along the Atlantic coast and Gulf Coast discussed in reports by the National Oceanic and Atmospheric Administration and the Intergovernmental Panel on Climate Change, and resource extraction pressures in the Appalachian Basin and Alaska North Slope. Conservation and restoration actions are implemented by partnerships including the Nature Conservancy, World Wildlife Fund, federal programs under the Land and Water Conservation Fund, state wildlife action plans coordinated by the Association of Fish and Wildlife Agencies, and international agreements such as the Ramsar Convention for wetlands.

Mapping, Assessment, and Management Methods

Mapping and assessment employ remote sensing from satellites like Landsat and sensors managed by the National Aeronautics and Space Administration, geospatial analysis by the United States Geological Survey and the National Geospatial-Intelligence Agency, and field inventories conducted by universities such as Oregon State University and the University of Florida. Management approaches integrate adaptive management used by the National Park Service, landscape-scale conservation exemplified by the Yellowstone to Yukon Conservation Initiative, and multi-stakeholder watershed planning seen in the Chesapeake Bay Program. Monitoring frameworks reference standards from the International Organization for Standardization and reporting to bodies like the Convention on Biological Diversity.

Category:Ecoregions of the United States