zondag 10 maart 2013

Canada, USA, Kluane / Wrangell-St. Elias / Glacier Bay / Tatshenshini-Alsek

These parks comprise an impressive complex of glaciers and high peaks on both sides of the border between Canada (Yukon Territory and British Columbia) and the United States (Alaska). The spectacular natural landscapes are home to many grizzly bears, caribou and Dall's sheep. The site contains the largest non-polar icefield in the world.

A unique area with high mountain peaks, foothills, glacial systems, lakes, streams, valleys and coastal landscapes. The Wrangell-St Elias region represents the most extensive array of glaciers and ice fields outside the polar region. These features and the high mountains of the Wrangell-St Elias, Chugach and Kluane ranges have resulted in the region becoming known as the 'Mountain Kingdom' of North America. Geologically the mountains are included in the Pacific mountain system and include the 130 km long Bagley ice field, the second-highest peak in the USA (Mount St Elias) and the largest piedmont glacier on the North American continent (Malaspina Glacier). Extensive lowlands are found only in the centre and along north-western fringes of the region. Elsewhere lowlands are sandwiched between mountains and sea or occur as narrow valleys and plateaux grading into upland and serrated peaks. Principal drainages include the Copper, Chitina, White, Alsek and Donjek rivers and tributaries. The Malaspina foreland coastal area comprises mainly long, straight piedmont glacial beaches cut through by numerous often sizeable glacial-melt drainage-ways.
The wide ranges of climatic zones and elevations in the region have resulted in a great variety of ecosystems representing three major biomes or broad vegetational subdivisions: the coastal coniferous biome; the northern coniferous biome; and the alpine tundra biome. The coastal coniferous biome includes coastal spruce-hemlock forests, tall shrub thickets and bogs and marshes.
The northern coniferous biome includes closed tall spruce and deciduous forests, open, low mixed evergreen and deciduous forests, tall shrub thickets and low shrub thickets.

The alpine tundra biome includes moist sedge and grass alpine tundra and dry alpine tundra: moist sedge and grass alpine tundra at 900-1,500 m on gradual slopes, meadow-like tundra composed of sedges and grasses interspersed with low shrubs such as blueberry and Labrador tea; and dry alpine tundra, on steeper mountain slopes and exposed ridges from 900 m to the elevation of perpetual ice and snow comprising low, matted alpine plants dominated by mountain avens.
There is a great variety of fauna reflecting the habitat diversity. Carnivores include coyote, grey wolf, red fox, short-tailed weasel, mink, wolverine, river otter, lynx and the more easily visible brown bear and black bear. A rare bluish colour phase of the black bear, known locally as the glacier bear, is centred in the vicinity of Yakutat. Other mammals include pica and snowshoe hare, arctic ground squirrel, beaver Castor, muskrat and porcupine. Rodents include the hoary marmot. Moose and caribou range in lower elevations and mountain goat and Dally sheep occupy high mountainous areas. Bison were introduced in 1950 and again in 1962. Black-tailed deer may occur along coastal fringes.
The avifauna includes spruce grouse, ruffed grouse, willow ptarmigan, rock ptarmigan, white-tailed ptarmigan, trumpeter swan and many song birds.
All five species of Alaskan Pacific salmon including red salmon, chum, silver salmon, pink salmon and king salmon spawn in park or preserve waters. Freshwater fish species include Dolly Virden, lake trout, steelhead, cutthroat trout, arctic grayling, turbot, round whitefish and humpback whitefish.

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