Snake River Plain ecoregion | |
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Ecology | |
Realm | Nearctic |
Borders | |
Geography | |
Country | United States |
States |
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Coordinates | 43°00′N 114°00′W / 43.0°N 114.0°W |
The Snake River Plain ecoregion is a Level III ecoregion designated by the United States Environmental Protection Agency (EPA) in the U.S. states of Idaho and Oregon. It follows the Snake River across Idaho, stretching roughly 400 miles (640 km) from the Wyoming border to Eastern Oregon in the xeric intermontane west. Characterized by plains and low hills, it is considerably lower and less rugged than surrounding ecoregions. Many of the alluvial valleys bordering the Snake River are used for agriculture. Where irrigation water and soil depth are sufficient, sugar beets, potatoes, alfalfa, small grains, and vegetables are grown. Elsewhere, livestock grazing is widespread. Cattle feedlots and dairy operations are found locally.
Potential natural vegetation is mostly sagebrush steppe, but barren lava fields and saltbush-greasewood associations also occur. Streams generally have lower gradients, are warmer, and have finer grained substrates than do streams in the montane ecoregions. Natural fish assemblages in the region are typically a mix of mesothermal minnows and suckers, but some stenothermal salmonids and sculpins are also present. The region has many large springs along the Snake River that support endemic fish and mollusc species. Shoshone Falls is a major zoogeographic barrier, and different species occur above and below it.[1][2]
The Snake River Plain ecoregion has been subdivided into ten Level IV ecoregions, as described below.