Low Arctic Tundra
The Low Arctic Tundra is a unique and fragile ecosystem located in the northernmost regions of the Earth, bordered by boreal forests to the south and mid-Arctic tundra to the north. This biome is characterized by its harsh climate, featuring long, frigid winters with temperatures often dipping below -22°F (-30°C) and short, cool summers where highs can reach over 41°F (5°C). The landscape is dominated by permafrost, a permanently frozen layer of soil that influences plant and animal life. Despite its cold conditions, the tundra is rich in biodiversity, hosting hundreds of species, including various vascular plants, mosses, and lichens, which thrive in the brief summer months.
Inhabitants of the Low Arctic Tundra include resilient herbivores like caribou, musk oxen, and Arctic hares, as well as a range of carnivores such as polar bears and Arctic foxes. Additionally, this ecosystem serves as a breeding ground for nearly 100 bird species, many of which rely on the tundra's habitat for survival. Climate change poses a significant threat to this delicate environment, with rising temperatures leading to habitat erosion, melting permafrost, and disruptions to the wildlife that depend on it. Conservation efforts are underway to protect this vital ecosystem and the indigenous cultures that have thrived in harmony with it for millennia. The future of the Low Arctic Tundra remains uncertain as it faces the dual pressures of environmental change and human influence.
Subject Terms
Low Arctic Tundra
- Category: Grassland, Tundra, and Human Biomes.
- Geographic Location: Arctic.
- Summary: The Arctic tundra is perhaps the most pristine human-inhabited biome. The low-Arctic tundra is home to hundreds of species, from inconspicuous reindeer lichen to majestic polar bears.
The Arctic tundra is one of the world's northernmost ecosystems. Low-Arctic tundra circles the globe, nestled between boreal forests to the south and mid-Arctic tundra to the north. Low-Arctic tundra makes up the northern mainland of North America, Scandinavia, and the Russian Federation. Indigenous people have inhabited the Arctic for thousands of years, and those living there today rely on subsistence harvests and traditional knowledge to survive. Though trees are absent from the tundra, it is rich with life and is home to a plethora of plants, rodents, caribou, birds, and carnivores.
Denizens of this ecosystem are specifically adapted to handle the harsh Arctic climate, but the fate of this region is unknown. Global climate change is altering the Arctic landscape and threatening all who reside in this wilderness. Indeed, the consensus among most scientific authorities is that the Arctic is affected more rapidly and to greater extremes than other areas of the Earth by the pressures—warmer water and air temperatures, altered salinity, and thermohaline circulation—of global warming. In part, this is due to the accelerated positive feedback loops between Arctic ice cover and albedo (reflectivity index), ice thickness, and age of the ice pack.
The climate of the low Arctic consists of long, bitter winters and little year-round precipitation. Arctic summers are short and chilly. Air temperature remains below freezing during most of the year, dipping below minus 22 degrees F (minus 30 degrees C) in February; highs in July exceed 41 degrees F (5 degrees C). Due to the cold climate, the soils of the Arctic are perennially frozen permafrost. The permafrost is about 656 feet (200 meters) deep, but the topmost layer melts seasonally, with soil reaching depths up to 31 inches (80 centimeters). Even with the low levels of precipitation, a mere four inches (100 millimeters) of summer rains can saturate the shallow soil and facilitate explosive plant growth. Annual precipitation can average up to 8 to 10 inches (200 to 254 millimeters) here; further north, where the annual rate is often less than 6 inches (150 millimeters), the area transitions to the Arctic Desert biome.
Plant Life
Hundreds of species of vascular plants, moss, and lichen richly carpet the tundra. Characteristic plants in this largely treeless biome are the low-lying perennials that live for several years, buried alive under the snows of winter and in full bloom under the 24-hour sunlight of high summer. Plant communities are delimited by soil microclimate. Sedge meadows dominate wet soils; diverse flowering plants occupy moist environments; dry areas are paved with tussocks of cottongrass. The vascular plants are far too many to enumerate, but some of the most alluring are the Arctic poppy, saxifrage, and Arctic lupine.
In addition to carpets of flowers, an abundance of bryophytes and lichen are distinguishing landscape features. Many of these plants have astonishing colors and are important components of herbivore diets. Red moss, among its shamrock-green counterparts, for example, creates a striking landscape accentuated by caribou grazing on reindeer lichen.
Mammalian Life
The tundra is home to herbivores large and small, including musk oxen, caribou, Arctic hares, ground squirrels, lemmings, and voles. Each species is adapted to the harsh conditions. Arctic herbivores are very resilient. Caribou, for example, travel up to 621 miles (1,000 kilometers) between sub-Arctic wintering grounds and calving sites on the tundra. Caribou, like other tundra mammals, have physical and physiological features that ameliorate the bitter winter conditions; they grow specialized winter coats, for instance, to shield them from the elements.
Only the Arctic ground squirrel escapes the frost by entering hibernation. Nonetheless, to stay alive, herbivores must not only prevail against the environment but also avoid predation. The Arctic is the citadel of carnivores, the most remarkable of which is the polar bear. Both polar and brown bears inhabit the tundra, and though they are closely related, only the polar bear is confined to the Arctic. Neither Arctic bear is strictly carnivorous: Polar bears prey upon seals on the coast, and grizzlies take down caribou, but both species enjoy feasting on berries and lush tundra grasses.
The Arctic is also home to red and Arctic foxes, wolves, wolverines, and weasels. Like brown bears, the wolves and red foxes are also found in forest ecosystems, yet they take advantage of the tundra where they can escape the human hunting pressures they are subject to elsewhere.
Bird Species
Mammals are not the lone fauna of the low Arctic tundra; the zone also provides breeding sites for nearly 100 bird species. Temperate-climate, predominantly wetland migrants such as cranes, swans, loons, and sandpipers use the tundra as breeding grounds. In addition to these visitors, inimitable species are permanent residents here, such as the snowy owl and the rock ptarmigan.
Because breeding in the Arctic is such a ubiquitous feature of wetland and shore birds, the survival of many populations is dependent on the security of Arctic habitat. Their security, like that of other species, is threatened by global climate change.
Conservation Efforts
The Arctic National Wildlife Refuge is a conservation region comprising 19.3 million acres (7.8 million hectares) in the Alaskan Arctic, the sole purpose of which is to conserve this one-of-a-kind wilderness and its wildlife. The largest hurdle to management of this ecosystem is global climate change. In relation to the rest of the world, the rate of climate change has ratcheted up in the Arctic. Warming temperatures have led to tundra erosion; rising sea levels; and the melting of permafrost, sea ice, and glaciers. All these events, taken together, are resulting in loss and deterioration of tundra habitats and an upset to the delicate balance of the ecosystem. Conservation initiatives are concerned with the preservation not only of wilderness, but also of the indigenous culture that is deeply rooted in the wilds of the north. In the face of habitat destruction in ecosystems around the world, the hinterlands of the Arctic tundra have become a key remaining pristine and unbroken habitat for humans—but the fate of this vulnerable ecosystem is yet unknown.
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