CEC_LEVEL_III_Descriptions_US_May2010
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CEC_LEVEL_III_Descriptions_US_May2010
Level III North American Terrestrial Ecoregions: United States DescriptionsPrepared for:North American Commission for Environmental Cooperation — www. CEC_LEVEL_III_Descriptions_US_May2010.cec.org393 rue St-Jacques oust, Suite 200. Montreal Quebec H2Y 1N9Prepared By:Glenn Griffith Corvallis. Oregon 541 754-4465 aggriffithiPpealGoixVersion Date:403091CEC LEVEL III Descriptions - United States Compiled by Glenn Griffith May 11, 2010* = shared region with Canada or Mexico2.2.1ARCTIC COA CEC_LEVEL_III_Descriptions_US_May2010STAL PLAINLocation: The northernmost ecoregion in the United States is bounded on the north and the west by the Arctic Ocean and stretches eastward neCEC_LEVEL_III_Descriptions_US_May2010
arly to the international boundary between Alaska and the Yukon Territory, Canada.Climate: The ecoregion has a dry, polar tundra or low arctic climateLevel III North American Terrestrial Ecoregions: United States DescriptionsPrepared for:North American Commission for Environmental Cooperation — www. CEC_LEVEL_III_Descriptions_US_May2010itation is low, about 140-200 mm.Vegetation: Treeless; wet graminoid herbaceous communities are the predominant vegetation cover, with sedges, rushes, mosses, lichens, and willows.Hydrology: Numerous thaw lakes dot the region. Streams and rivers flow north from the mountainous ecoregion to the south CEC_LEVEL_III_Descriptions_US_May2010. They tend to be sluggish and meandering to the west, more braided to the east. Terrain: The poorly drained, flat to undulating coastal plain rises gCEC_LEVEL_III_Descriptions_US_May2010
radually from sea level to the adjacent foothills and Is underlain by thick permafrost. Pingos, peat ridges, frost bolls, and Ice-wedge polygons are cLevel III North American Terrestrial Ecoregions: United States DescriptionsPrepared for:North American Commission for Environmental Cooperation — www. CEC_LEVEL_III_Descriptions_US_May2010arctic ground squirrels, many species of waterfowl and seabirds, arctic cisco, Dolly Varden, broad whitefish.Land Use Human Activities: Native subsistence trapping, hunting, and fishing. Traditional dependence on large marine mammals (e.g., whales, walrus, seals) for food and materials. Oil and gas CEC_LEVEL_III_Descriptions_US_May2010activities.*2.2.2 ARCTIC FOOTHILLSLocation: The east-west extent of the ecoregion stretches from Mackenzie Bay in the Yukon Territory, Canada, to theCEC_LEVEL_III_Descriptions_US_May2010
Chukchi Sea off northern Alaska.Climate: The ecoregion has a mostly dry, polar tundra climate, bordering on severe mid-latitude subarctic. It is somewLevel III North American Terrestrial Ecoregions: United States DescriptionsPrepared for:North American Commission for Environmental Cooperation — www. CEC_LEVEL_III_Descriptions_US_May2010re ranges from -13°to -7^2. Summer mean temperature Is approximately 4.5'C and winter mean is -24qc. The mean annual precipitation ranges from 200 mm to 350 mm.Vegetation: The region is predominantly treeless and is vegetated primarily by mesic graminoid herbaceous communities, dominated by mixed sh CEC_LEVEL_III_Descriptions_US_May2010rub-sedge tussock tundra. Willow thickets and alders occur along rivers and small drainages and Dryas tundra is found on ridges.Hydrology: Low to mediCEC_LEVEL_III_Descriptions_US_May2010
um density drainage networks. Many braided streams and rivers. Few lakes in the foothill areas except oxbow lakes along major stream valleys. Some wetLevel III North American Terrestrial Ecoregions: United States DescriptionsPrepared for:North American Commission for Environmental Cooperation — www. CEC_LEVEL_III_Descriptions_US_May2010the Brooks Range (2.3.1) on the south. The hills and valleys of the region have better defined drainage patterns than those found in the coastal plain to the north and have fewer lakes. The area is underlain by thick permafrost and many ice-related surface features are present. Soils are often satur CEC_LEVEL_III_Descriptions_US_May2010ated and have thick organic horizons.Wildlife: Caribou, muskox, brown bear, gray wolf, red and arctic fox. arctic ground squirrel, peregrine falcon, sCEC_LEVEL_III_Descriptions_US_May2010
nowy owl. ptarmigan, waterfowl and shorebirds, arctic char, arctic grayling.Land Use Human Activities: Subsistence and recreational fishing, hunting, Level III North American Terrestrial Ecoregions: United States DescriptionsPrepared for:North American Commission for Environmental Cooperation — www. CEC_LEVEL_III_Descriptions_US_May2010d the Yukon and Kuskokwim River delta area along the Bering Sea ot western Alaska.Climate: The region has a subart lit c lirnale ailec ted by both marine and continental climatic influences. Il has t ool summers and severe winters. The mean annual temperature is approximately -6V.. The mean annual p CEC_LEVEL_III_Descriptions_US_May2010rec ipilalion ranges from 250-500 mm. The southern portion is warmer and welter than the northern portion.Vegelation: Coastal vegetation dominated byCEC_LEVEL_III_Descriptions_US_May2010
brat kish marshes anti w et meadows. Inland, permalnjsl-dominaled landscapes support low birch-erit at eons shrubs and setlge-lusstit k anil sedge-mosLevel III North American Terrestrial Ecoregions: United States DescriptionsPrepared for:North American Commission for Environmental Cooperation — www. CEC_LEVEL_III_Descriptions_US_May2010kes and thaw sinks. Streams are sluggish with wide meanders.Terrain: Flat, lake-dotted coastal plains and river deltas are t harat lerislit of the region. Soils are wet anti the permafrost table is shallow. Older coastal deposits of marine and alluvial sediments cover most of region. A lew low volca CEC_LEVEL_III_Descriptions_US_May2010nic hills occur.Wikilife: Moose, black hear, caribou, gray wolf, sandhill cranes, waterfowl including brant, emperor geese, and tundra swans; shorebirCEC_LEVEL_III_Descriptions_US_May2010
ds such as Sabines’ gulls, black turnstones, and western sandpipers. In near shore coastal waters, beluga and bowhead whales, walruses, and seals. In Level III North American Terrestrial Ecoregions: United States DescriptionsPrepared for:North American Commission for Environmental Cooperation — www. CEC_LEVEL_III_Descriptions_US_May2010rmanent and seasonal settlements throughout the region, mostly adjacent to rivers or along the coast. Subsistence and recreational fishing and hunting. Some minor gold and silver mining.2.2.4SEWARD PENINSULA CEC_LEVEL_III_Descriptions_US_May2010Level III North American Terrestrial Ecoregions: United States DescriptionsPrepared for:North American Commission for Environmental Cooperation — www.Gọi ngay
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