Look at the map of the United States below. It has the country divided up in 2 ways – one familiar and one that could be new to you. The familiar division is by states. State boundaries separate political jurisdictions and they were drawn by early colonial settlers and our government. Can you see the state that you live in?
Compare the state boundaries to the colorful sections of the map. They don’t match up! Parts of Florida belong to the same region as Virginia. These kinds of divisions are called "ecoregions". Whereas state boundaries were created by people, the ecoregion boundaries on this map were created by Mother Nature.
What is an Ecoregion?
Ecoregions are areas that have similar climate, geology and soils. These abiotic (non-biological) factors determine what plants and animals can live in the ecosystem. Even though two places might be far apart, if they are part of the same ecoregion, we can predict that they will have similar species.
For example, a mixed deciduous-coniferous forest in Maine will have similar plants and animals to a mixed deciduous-coniferous forest in Minnesota. By using an ecoregion map, we can gain a lot of clues into the ecology of different places in the United States and the world.
The Ecoregion Map of the United States
The ecoregion map we display on this page, designed by the U.S. Forest Service and Robert G. Bailey, is one of the most well-known. Bailey’s ecoregion map divides ecoregions into four levels of detail. At the broadest scale, the United States is divided according to patterns of climate. At the province level, ecoregions are divided according to vegetation and other natural land cover. To understand each specific ecoregion of the United States, please visit the US Forest Service website.
The ecoregions you might be most familiar with are:
- Subtropical (Florida, coastal Southeastern United States)
- Tundra (northern Alaska)
- Temperate Steppe (the Great Plains)
- Marine Mountains (coastal Washington and Oregon)
- Desert and Desert Mountain (Nevada and parts of New Mexico)
- And many more!
Why care about Ecoregions?
By studying ecoregions, we begin to understand more about the history, ecology and biodiversity of the United States.
- Conservationists use ecoregions to help in habitat protection and restoration projects and to produce recovery plans for endangered species.
- Historians and biologists study ecoregions to map out the connection between the settlements of early indigenous peoples and wildlife and how the ecology has changed over time.
- Gardeners study their local ecoregion to determine what native flowers to plant in their Certified Wildlife Habitat™.
Do you need help deciding which plants to grow in your garden? By using an ecoregional pollinator guide, you can learn what native plants can be found in your ecoregion and what pollinators they attract. It is a great way to support native wildflowers, bees, butterflies and other invertebrates. To find an ecoregional pollinator guide for your region visit the Pollinator Partnership.
US Forest Service-Ecoregions of the United States