Search results
Results from the WOW.Com Content Network
The High Southern Cascades Montane Forest ecoregion is an undulating, glaciated, volcanic plateau punctuated by isolated buttes and cones. Many tarns occur. With an elevation that varies from 4,000 to 8,200 feet (1,200 to 2,500 m), it is an intermediate zone between the Southern Cascades and the Subalpine/Alpine zone.
The level III ecoregions in Oregon are the Coast Range (1), Willamette Valley (3), Cascades (4), Eastern Cascades Slopes and Foothills (9), Columbia Plateau (10), Blue Mountains (11), Snake River Plain (12), Klamath Mountains (78), and Northern Basin and Range (80). (Compare to map of Level IV ecoregions.)
The Southern Cascades Slope ecoregion is a transitional zone between the Cascades ecoregion and the drier Eastern Cascade Slopes and Foothills, characterized by moderately sloping mountains with medium to high gradient streams. Elevation varies from 3,600 to 6,300 feet (1,100 to 1,900 m).
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 term "Cascades" was first used for the Cascades Rapids, as early as the Astor Expedition. The earliest attested use of the term for the mountain range dates to 1825, in the writings of botanist David Douglas. During geological explorations in the early 1900s the term was first applied to the region. [8]
English: Level IV ecoregions in the Cascades ecoregion, as defined by the EPA. This map is a draft and may now be slightly outdated. This map is a draft and may now be slightly outdated. For more information about these ecoregions, see [1]
The Ecology of the North Cascades is heavily influenced by the high elevation and rain shadow effects of the mountain range. The North Cascades is a section of the Cascade Range from the South Fork of the Snoqualmie River in Washington, United States, to the confluence of the Thompson and Fraser Rivers in British Columbia, Canada, where the range is officially called the Cascade Mountains but ...
"Level III" subdivides those regions again into 182 ecoregions. [1] [2] "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.