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Alaska Peninsula montane taiga

The Alaska Peninsula Montane Taiga ecoregion stretches along the southern, Pacific Ocean side of the Alaska Peninsula, from the mouth of Cook Inlet westward to (and including) Unimak Island. It also includes the majority of the Kodiak Island archipelago. Most of the ecoregion consists of rounded ridges ranging between sea level and 1,200 m in elevation, but several steep, rugged volcanic peaks rise to 1,400-2,600 m. The slopes are covered by dwarf scrub communities on upper slopes and in exposed areas and low scrub in lower, more protected sites. The dwarf scrub communities are dominated by crowberry (Empetrum nigrum) and include other ericads (Vaccinium spp.), arctic willow (Salix arctica), and white mountain-avens (Dryas octopetala). Low scrubs are dominated by willows (Salix spp.), along with dwarf shrub species and some forbs. Tall scrub communities of alder (Alnus sinuata) and willow also occur in the lower elevations, and some floodplains and south-facing slopes support stands of balsam poplar (Populus balsamifera). (Gallant et al. 1995)

The climate in the Alaska Peninsula Montane Taiga ecoregion is dominated by maritime influences, with high precipitation and moderate temperature ranges. Precipitation varies greatly, ranging from 600 mm to 3,300 mm along the coasts, and reaching more than 4,000 mm in high elevations. Winter temperatures average between -11°C and 1°C, and in summer between 6°C and 15°C. The maritime climate has kept the region generally free from permafrost, but it was heavily glaciated in the Pleistocene, and retains glaciers on the higher peaks. Soils are mostly Typic Haplocryands and Typic Vitricryands. They have formed from volcanic ash and cinders and erode easily in the heavy rains. This can hinder vegetation development. (Gallant et al. 1995)

Main activities are commercial fishing and processing, mining and subsistence fishing and hunting. Indigenous communities rely mostly on fishing and the hunting of marine mammals. Gold, silver, lead, and copper have been mined on a small scale, and some coal and petroleum extraction occurs. (Bailey et al. 1994)

No information is available on fire occurrence in this ecoregion. Perhaps the most regular disturbance factors are the frequent and enormously violent winter storms which buffet the region and the more infrequent volcanic eruptions and resulting ash falls. The combination of ash slopes and heavy storms creates a very readily eroded landscape, which continually disturbs the growth of vegetation.

  • Scientific Code
    (NA0601)
  • Ecoregion Category
    Nearctic
  • Size
    18,500 square miles
  • Status
    Relatively Stable/Intact
  • Habitats

Description
Biological Distinctiveness
This ecoregion provides important seasonal staging and migration habitat for many waterfowl, and supports populations of caribou (Cervus elaphus), moose (Alces alces), Arctic ground squirrel (Spermophilus parryii), and Alaskan hare (Lepus othus) (Bailey et al. 1994). Large numbers of brown bears inhabit the ecoregion, including the largest brown bears on earth - the Kodiak brown bears on Kodiak Island (Ursus arctos middendorffi). The bears congregate for the large salmon runs which occur in summer and fall at the short, steep rivers, especially the McNeil River and those in Katmai National Park. The bears and other top level predators exist in numbers within their natural range of variation, with predator-prey relationships intact.

Exceptionally large sea bird colonies exist along the coastlines as well. For example, Unimak Island supports over 500,000 tufted puffins. Colonies in Stepovak Bay support 200,000 murres and 300,000 puffins. The Semidi Islands have 500,000 fulmars and 650,000 murres (Sowls et al. 1978)

Conservation Status

Habitat Loss and Degradation
The Alaska Peninsula Montane Taiga is almost entirely intact, with habitat loss almost exclusively restricted to the localized effects of development surrounding the small communities and settlements along the coastline.

Remaining Blocks of Habitat
As there is localized and minimal habitat loss in this ecoregion, the entire ecoregion remains essentially intact.

Degree of Fragmentation
The long, thin shape of this ecoregion and its many islands create a naturally fragmented landscape, but anthropogenic fragmentation is very slight.

Degree of Protection
Important protected areas include:

•Alaska Peninsula National Wildlife Refuge - southwestern Alaska
•Izembek National Wildlife Refuge - southwestern Alaska
•Kodiak National Wildlife Refuge - southwestern Alaska
•Aniakchak National Monument and Preserve - southwestern Alaska
•Becharof National Wildlife Refuge - southwestern
•Katmai National Park and Preserve - southern Alaska
•McNeil River State Game Sanctuary - southwestern Alaska
Types and Severity of Threats
Major threats include:

•continued habitat damage from existing ranching, feral cattle on some islands and predation effects on some islands from feral foxes.
•Some potential for over harvest of game species, especially for brown bear populations near McNeil River.
Suite of Priority Activities to Enhance Biodiversity Conservation

•Protection of brown bear populations around McNeil River from unsustainable harvest just outside the State Wildlife Refuge.
•Continue to consolidate Kodiak National Wildlife Refuge holdings by purchasing properties with Exxon Valdez settlement funds.
Conservation Partners

•Conservation Fund
•Friends of McNeil River
Relationship to other classification schemes
This ecoregion is identical to Gallant ecoregion 113. Major delineation features are the high relief and scrub vegetation communities. The Bering Sea side of the peninsula (Beringia Lowland Tundra ecoregion) is lower, flatter, and supports wet and moist tundra communities instead.

Prepared by: R. Hagenstein, T. Ricketts

 

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