Alaska Peninsula montane taiga

Category: Forest Biomes.

Geographic Location: North America.

Summary: The Alaska Peninsula montane taiga is a rugged terrain hosting elevation-variegated plants and fauna ranging from vast migratory bird rookeries to the huge Kodiak bear.

The Alaska Peninsula montane taiga covers some 18,500 square miles (48,000 square kilometers) of rugged vertical terrain along the southern slopes of the Alaska Peninsula, the Kodiak Archipelago, and as far west as Unimak Island in the eastern Aleutian Islands chain. Situated below and around volcanic peaks of up to 8,000 feet (2,500 meters), floral and faunal features of this biome thrive in elevations of 4,000 feet (1,200 meters) and higher.

Taiga is a characteristic northern coniferous forest type, with great stretches found across North America, Europe, and Asia. The Alaska Peninsula montane taiga exists in a climate of cold, snowy winters and rainy, humid, warm summers; due to its coastal position, the high-elevation harshness here is somewhat reduced by the moderating influence of Pacific Ocean temperature effects.

Taiga forests typically lack the great biological diversity of many tropical and temperate forest systems. The Alaska Peninsula montane taiga biome, however, does host a tremendous summer insect population which in turn attracts vast bird migrations during nesting season.

Vegetation Communities

Supporting its flora types, the Alaska Peninsula montane taiga enjoys a moderate scale of seasonal temperatures as well as a high precipitation regime of from 24 to 130 inches (60 to 330 centimeters) along the coasts to more than 160 inches (400 centimeters) in the highest elevations. The temperatures in winter range between 12 to 34 degrees F (minus 11 to 1 degree C), with summer ranges from 42 to 59 degrees F (6 to 15 degrees C). There is little in the way of permafrost terrain, but glaciers are found on the high peaks.

Upper slopes of the biome feature dwarf scrub vegetation dominated by black crowberry (Empetrum nigrum), along with such species as wandering daisy (Erigeron peregrinus), mountain white radish or cathaleaf avens (Geum calthifolium), yellow-flowered sedge (Carex anthoxanthea), Nootka reedgrass (Calamagrostis nutkaensis), and the moss Pleurozium schreberi. Toward the lower elevations, various willows (Salix spp.) become common; lower still are found stands of green alder (Alnus viridis) and, especially in the floodplains, balsam poplar (Populus balsamifera).

Animal Populations

The Alaska Peninsula montane taiga supports considerable herds of caribou, as well as moose, Arctic ground squirrel (Spermophilus parryii), and Alaskan hare (Lepus othus). The Kodiak bear (Ursus arctos middendorffi) is an outstanding endemic—unique to this biome—species, considered among the largest bears in the world. The Kodiak and other brown bears gather periodically in alluvial plains here for salmon runs in summer and fall. At the Katmai National Park and Preserve, this activity is a focal point for tourists and scientists alike, who annually congregate at Hallo Bay, Geographic Harbor, Swikshak Lagoon, Moraine Creek, and related areas. Adjacent to Katmai is the McNeil River State Game Sanctuary, containing the full, 35-mile length of this river, which is also a prime bear-watching hot spot.

Migratory waterfowl are another key component of the Alaska Peninsula montane taiga, with estimated colony sizes of 500,000 tufted puffins (Fratercula cirrhata) on Unimak Island, and 650,000 common murres (Uria aalge) and 500,000 northern fulmars (Fulmarus glacialis)in the Semidi Islands.

Pressures and Threats

Leading human activities in the area include commercial fishing and processing—by far the most extensive industry—along with mining and subsistence activities such as hunting and fishing. There are many small communities along the water which rely mostly on fishing combined with hunting marine mammals. There is a fairly limited amount of coal and petroleum extraction, as well as scattered mining of gold, lead, silver, and copper. There are also several active or former military installations that house toxic waste storage facilities.

Taiga systems are generally susceptible to wildfires; trees in these areas adapt by growing thick bark. Therefore, the fires will burn away the upper canopy of the trees and let sunlight reach the ground. Through this cycle, new plants will grow and provide food for animals that would have otherwise been hard-pressed to find sufficient nutrition from a conifer-dominant landscape. The Alaska Peninsula montane taiga, doused regularly with ocean spray and high humidity, is generally not as susceptible to wildfires as other taiga regions in Europe and Asia.

Violent winter storms are frequent, however, driving hillside erosion. Infrequent but sometimes extensive volcanic activity in this Ring of Fire geographic area produces quantities of ash that can blanket an area and stunt plant growth.

The World Wildlife Fund, in its in-depth study of the area, concluded that the Alaska Peninsula montane taiga biome is almost entirely intact, with minor habitat loss and degradation being confined to the localized effects of development around the small communities and villages along the coast. Much of the area is protected, including such zones as the Alaska Peninsula National Wildlife Refuge, Izembek National Wildlife Refuge, Kodiak National Wildlife Refuge, Aniakchak National Monument and Preserve, Becharof National Wildlife Refuge, as well as the Katmai and McNeil reserves noted above.

Still there is the threat of gradual habitat degradation from existing ranching activity, and the subsequent release of feral cattle on some islands, as well as predation effects from feral foxes. Brown bears in the biome are considered in jeopardy from overhunting; stabilizing the brown bear population along the McNeil River is one of the prioritized biodiversity conservation measures in the region. Another goal is to consolidate Kodiak National Wildlife Refuge holdings using Exxon Valdez settlement funds to purchase properties.

Further threats of climate change and variable weather events also hold potential threats to this biome. The taiga ecosystem is maintained by its precipitation volume and its dependable, moderated temperatures for each season. With the looming threat of climate change, this balance may be altered and could sharply impact this ecosystem in unprecedented ways.

Bibliography

Hulten, Eric. Flora of Alaska and Neighboring Territories: A Manual of the Vascular Plants. Palo Alto, CA: Stanford University Press, 1968.

Scheffer, Victor B. and Olaus Johan Murie. Fauna of the Aleutian Islands and Alaska Peninsula. Charleston, SC: Bibliobazaar Nabu Press, 2011.

Vitt, Dale H., Janet E. Marsh, and Robin B. Bovey. Mosses, Lichens, and Ferns of Northwest North America. Auburn, WA: Lone Pine Publishing, 1988.