COLORADO PLATEAUS: Toquerville-Zion National Park
Location: Located between the Southern Rocky Mountains on the east and the Wasatch Range to the west, the region occupies most of eastern and southern Utah, western Colorado, and small portions of northern Arizona and northwestern New Mexico.
Zion Natural History Exhibits
Climate: The ecoregion has a dry, mid-latitude steppe climate. It is marked by hot summers with low humidity, and cool to cold dry winters. The mean annual temperature ranges from approximately 5°C at high elevations in the north to 15°C in southern deep canyons along the Colorado River. The frost-free period ranges from 50 days to more than 220 days. The mean annual precipitation is 298 mm, ranging from 130 mm in arid canyons to more than 800 mm at high elevations.
Vegetation: Low elevation basins and canyons are sparsely vegetated with blackbrush, shadscale, fourwing saltbush, and galleta grass. Uplands and higher valleys have Wyoming big sagebrush, black sagebrush, pinyon-juniper woodlands and at higher elevations some areas of Gambel oak, mountain mahogany, aspen, and some Douglas fir. There is generally less grassland than in the Arizona/New Mexico Plateau (10.1.7) to the south.
Hydrology: The Virgin River is Utah’s first designated wild and scenic river. It is one of the few western rivers that is not controlled by dams; although the last 30 miles of the Virgin River forms the north arm of Lake Mead . River water levels are dependent on the annual snow pack of the surrounding mountains. River rafters enjoy the steep riverbed during spring runoff as they navigate a drop that averages 70 feet per mile (10 times steeper than the Colorado River through the Grand Canyon).
Terrain: Rugged tableland topography with precipitous side-walls mark abrupt changes in local relief, often from 300 to 600 meters. The region is more elevated than the Wyoming Basin (10.1.4) to the north; however, it also has large low-lying areas in river canyons. The uplifted, eroded, and deeply dissected tableland of sedimentary rock contains benches, mesas, buttes, cliffs, canyons, and salt valleys. Elevations range from about 900 m to over 3,000 m. Entisols and Aridisols are typical soil orders, with mostly mesic and frigid soil temperature regimes and aridic and ustic soil moisture regimes.
Wildlife: The Virgin River is located where three ecoregions intersect: Colorado Plateau, Great Basin, Mojave Desert. Unique plant and animal communities and species are supported by the water of the Virgin River system. Many of these species are found no where else in the world; and many species are endangered or considered sensitive species within the State of Utah. Wildlife found in this ecoregion includes: woundfin, Virgin River chub, Virgin spinedace, flannelmouth sucker, desert sucker, speckled dace, and Southwestern Willow Flycatcher.
Land Use/Human Activities: National Park and Bureau of Land Management lands are located in this ecoregion. U.S. Fish and Wildlife Service, The National Park Service, and Bureau of Land Management are working with local agencies to develop Habitat Conservation Plan to protect this unique ecoregion. Larger towns include Virgin, Rockville, and Springdale.
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Commission for Environmental Cooperation; North American Terrestrial Ecoregions—Level III; April 2011. Wikipedia; Virgin River.
Photos taken in October 2013 along highways-
Just Another Nature Enthusiast Photography by Jane Wilson is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.