Copper Plateau taiga
The Copper Plateau Taiga is a subarctic forest biome located in southeastern Alaska, predominantly characterized by its low elevation, discontinuous permafrost, and extensive coniferous forests. Spanning approximately 6,600 square miles (17,000 square kilometers), this region features a mix of flatland and gently rolling plains, surrounded by high mountains and bordering the tundra ecosystem. The climate is marked by long, cold winters and short, warm summers, with annual temperatures averaging from minus 17 degrees F (minus 27 degrees C) in winter to 70 degrees F (21 degrees C) in summer.
The plant life in the Copper Plateau Taiga is adapted to its poor drainage and acidic soils, with a canopy dominated by black spruce and other conifers, as well as diverse ground cover of shrubs, mosses, and lichens. The region supports a variety of wildlife, including bears, moose, and migratory birds, indicating a rich ecological tapestry influenced by seasonal cycles and local waterways. However, the biome faces significant threats from development, logging, and the impacts of climate change, which can alter both its flora and fauna. Conservation efforts are in place to protect this unique ecosystem, but ongoing challenges necessitate careful management to ensure its survival.
Copper Plateau taiga
- Category: Forest Biomes.
- Geographic Location: North America.
- Summary: The Alaskan Copper Plateau Taiga is a subarctic extensive, low-elevation forest characterized by areas of discontinuous permafrost. This biome is largely intact, but is threatened by development and logging.
The Copper Plateau taiga is located in southeastern Alaska in the United States. Taiga is the predominant biome within the Alaskan interior, and it is part of the subarctic ecoregion The taiga is also known as a boreal forest. The low-elevation terrain consists of a large plateau featuring a mixture of flatland and gently rolling plains marked by discontinuous permafrost. Coniferous forest stands predominate.
The Copper Plateau Taiga biome is approximately 6,600 square miles (17,000 square kilometers) in size, and lies at an elevation between 1,600 to 3,000 feet (400 to 900 meters) above sea level. It is part of the larger taiga biome stretching from Alaska and Canada into the northeastern and midwestern United States. The taiga was once the site of a large lake and massive glaciers during the Great Ice Age of the ancient Pleistocene Era. High mountainous regions surround the area and it borders on the tundra ecosystem to its north.
Geography and Climate
The land of the taiga is shallow and low-lying, with poor drainage. The soils are generally acidic, resulting in a dearth of organic matter or nutrients in the topsoil. The taiga ecosystem includes the Copper and Susitna Rivers, as well as central regional lakes such as Lake Louise, Tyone Lake, Paxson Lake, and Susitna Lake. There are also vast numbers of other small lakes, pools, wetlands, bogs, and marshes.
Long, dark, cold winters and short, warm summers are characteristic of this region. Sunlight hours are greatly reduced in winter while summer sun exposure can last up to 20 hours per day. Annual temperatures average a daily minimum of minus 17 degrees F (minus 27 degrees C) in the winter and a daily maximum temperature of 70 degrees F (21 degrees C) in the summer. In the region's western reaches, average temperatures are often below freezing for more than half the year. Annual precipitation consists of summer rains and winter snows, ranging from 10 to 18 inches (25 to 46 centimeters). The northern taiga receives the most precipitation; the summer is the wettest season.
Vegetation
The area's plant life is well adapted to survival in the cool, poorly drained soils characteristic of the taiga environment. Vegetation varies according to factors such as sun exposure, drainage, and the absence or presence of permafrost. Permafrost is not present throughout the taiga, allowing for habitat diversity. Some trees, such as aspen, cottonwood, and white spruce, only grow in the areas of permafrost absence. Hills with southern exposure tend to be permafrost-free, while those with northern exposure contain permafrost. The predominant conifer and evergreen trees generally do not lose their leaves or needles in the fall season, hold water, and have shapes that prevent large accumulations of snow within their branches.
The Copper Plateau Taiga biome is dominated by stretches of subarctic forest featuring trees of varying species and short to moderate heights. Coniferous evergreen forests and woodlands compose the majority of the treescape. Dense forest canopies and closely spaced trees are common within the conifer forests. Black spruce (Picea mariana) is the dominant tree within these areas. Other characteristic tree species include white spruce (Picea glauca), dwarf birch (Betula glandulosa and Betula nana), black cottonwood (Populus trichocarpa), tamarack, and quaking aspen (Populus tremuloides).
Below the taiga forest canopy is a ground cover composed of shrubs, mosses, lichens, and ferns. The forest ground cover contains accumulated plant materials and acts as a storehouse for carbon. The many wetland areas support low scrub bog communities dominated by birch and ericaceous (heath) shrubs. The taiga also supports a variety of sedges, herbs, and berries. Common cottongrass (Eriophorum angustifolium), bogbean (Menyanthes trifoliata), Arctic sweet coltsfoot (Petasites frigidus), and marsh cinquefoil (Potenilla palustris) are among the ecosystem's native plant species.
The northern edges of the Copper Plateau Taiga feature another distinct habitat. The North American taiga biome lies just south of the tundra biome. The two biomes meet within a transitional zone featuring a blend of taiga and tundra habitat characteristics and species, known as a tree-line ecotone. Here, the tree canopy thins as it transitions from the taiga to its neighboring tree-less tundra.
Animal Types
Animals have adapted various survival mechanisms for life in the taiga, such as seasonal migration, seasonal cycles of fur growth and shedding, camouflage, hibernation, and burrowing under the snow. Brown bears, badgers, beavers, reindeer, mice, moles, foxes, wolverines, squirrels, moose, and caribou are all native to the taiga region. The area's large lakes and rivers support fish habitats and nesting sites. Salmon live within the Copper River; notable species are the chinook, king, and sockeye.
The area is home to both permanent and migratory bird populations. Birds nest along the taiga's wetland areas such as Lake Louise and Paxson Lake. Birds include the trumpeter swan, among the largest birds found within the North American continent. Migratory birds visit the area during the spring season, nesting among the numerous lakes and rivers. The warmer temperatures signal the hatching of insects, which provide a readily available, well stocked food source.
Invasive animal species introduced into the Copper Plateau Taiga ecosystem include the mallard, Canada goose, great horned owl, red fox, wolf, least weasel, American beaver, ermine, and snowshoe hare. The taiga does not house any significant numbers of endangered species, although the state of Alaska maintains the Nelchina Caribou Special Management Area. Wildfires are not a significant threat, as their rates of occurrence are low and those that do occur tend to be small in size. The heat generated by wildfires, however, can change soil characteristics in the affected area.
Human Impact
The Copper Plateau Taiga biome and its environs are home to several ecologically protected areas, such as the Nelchina and the Wrangell-St. Elias National Park. Conservation organizations working within the area include the Copper Country Alliance, the Copper River Watershed Forum, and the National Parks and Conservation Association. While little of native habitat here has been lost, development and the timber industry are significant potential ecological threats. Scientists estimate that total habitat loss is at approximately 10 percent.
Development and road building is most extensive in the region's Glenallen area. The northwestern portion is accessible by the Denali Highway. The timber industry operates within the Copper River Valley and on Alaskan Native Regional Corporation lands within the vicinity of Chitina. Natural areas are popular sites for tourism and recreation; they also support both sport and subsistence hunting and fishing.
Global climate change has already been affecting this ecoregion; the boreal forests have been experiencing some of the greatest temperature increases on the planet. Warmer summers may account for stunted tree growth, and summer warming trends may cause some plant habitats to metamorphose into others: for instance, a forest land may over time become more suitable as a grassland. Tree-damaging insects may also benefit from fewer days per year of colder temperatures that would normally keep their populations down. Warming temperatures can lead to thawing permafrost, which creates several problems within the forest. The increased water and a lack of drainage makes it difficult for trees to take root. Further, the thawing can release carbon that then dissolves into lakes, rivers, and streams, causing them to brown. Future concerns for the Copper Plateau Taiga include climate change, likely increases in timber harvesting, and potential use of unsustainable industry practices.
Bibliography
Beresford-Kroeger, Diana and Christian H. Kroeger. Arboretum Borealis: A Lifeline of the Planet. Ann Arbor: University of Michigan Press, 2010.
Chapin, F. Stuart. Alaska's Changing Boreal Forest. New York: Oxford University Press, 2006.
Kasischke, Eric S. and Brian J. Stocks. Fire, Climate Change, and Carbon Cycling in the Boreal Forest. New York: Springer, 2000.
“The World’s Boreal Forests May Be Shrinking As Climate Change Pushes Them Northward.” Colorado State University, 3 Nov. 2023, source.colostate.edu/the-worlds-boreal-forests-may-be-shrinking-as-climate-change-pushes-them-northward/. Accessed 16 Nov. 2024.
Van Cleve, K. Forest Ecosystems in the Alaskan Taiga: A Synthesis of Structure and Function. New York: Springer-Verlag, 1986.