Pacific Coastal Mountain icefields and tundra is a

tundra In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless moun ...

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of l ...

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

, and

Yukon Yukon (; ; formerly called Yukon Territory and also referred to as the Yukon) is the smallest and westernmost of Canada's three territories. It also is the second-least populated province or territory in Canada, with a population of 43,964 as ...

, as defined by the

World Wildlife Fund The World Wide Fund for Nature Inc. (WWF) is an international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named the Wo ...

(WWF) categorization system.

Setting

This ecoregion occupies the rugged slopes of the

Coast Ranges The Pacific Coast Ranges (officially gazetted as the Pacific Mountain System in the United States) are the series of mountain ranges that stretch along the West Coast of North America from Alaska south to Northern and Central Mexico. Although the ...

, stretching from the

Kenai Peninsula The Kenai Peninsula ( Dena'ina: ''Yaghenen'') is a large peninsula jutting from the coast of Southcentral Alaska. The name Kenai (, ) is derived from the word "Kenaitze" or "Kenaitze Indian Tribe", the name of the Native Athabascan Alaskan tribe ...

of south-central Alaska to Portland Inlet in British Columbia. Elevations range from sea level to over .

Glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its Ablation#Glaciology, ablation over many years, often Century, centuries. It acquires dis ...

s and subpolar icefields are the dominant physiographic influences of this ecoregion.

Climate

At lower elevations this ecoregion has a

subarctic climate The subarctic climate (also called subpolar climate, or boreal climate) is a climate with long, cold (often very cold) winters, and short, warm to cool summers. It is found on large landmasses, often away from the moderating effects of an ocean, ge ...

( Köppen '' Dfc '') with cool summers and cold winters. At higher elevations this ecoregion has a

tundra climate The tundra climate is a polar climate sub-type located in high latitudes and high mountains. undra climate https://www.britannica.com/science/tundra-climateThe Editors of Encyclopaedia Britannica, 2019 It is classified as ET according to Köppen ...

( Köppen '' ET '') with cold summers and very cold winters. Annual precipitation ranges from about to over , the majority of which falls as

snow Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughout ...

. The mean annual temperature is -0.5°C (31.1°F), with an average summer temperature of 10°C (50°F) and an average winter temperature of -11.5°C (11.3°F).

Ecology

Flora

Much of the ecoregion at lies beneath glaciers and icefields and is largely devoid of vegetation. Where the ground is vegetated, communities are dominated by dwarf and low shrub communities, including mountain heath and ericaceous shrubs. Subalpine forests of

alpine fir Alpine may refer to any mountainous region. It may also refer to: Places Europe * Alps, a European mountain range ** Alpine states, which overlap with the European range Australia * Alpine, New South Wales, a Northern Village * Alpine National Pa ...

, mountain hemlock, and

Sitka spruce ''Picea sitchensis'', the Sitka spruce, is a large, coniferous, evergreen tree growing to almost tall, with a trunk diameter at breast height that can exceed 5 m (16 ft). It is by far the largest species of spruce and the fifth-larg ...

dominate middle elevations. Forests of western hemlock, subalpine fir and Sitka spruce dominate lower elevations. Forests on the

represent a transitional forest type between coastal

temperate rainforest Temperate rainforests are coniferous or broadleaf forests that occur in the temperate zone and receive heavy rain. Temperate rain forests occur in oceanic moist regions around the world: the Pacific temperate rain forests of North American Paci ...

s characteristic of coastal areas and boreal forest and taiga communities characteristic of interior Alaska.

Fauna

Mammals found throughout the lower to middle elevations of this ecoregion include

American black bear The American black bear (''Ursus americanus''), also called simply a black bear or sometimes a baribal, is a medium-sized bear endemic to North America. It is the continent's smallest and most widely distributed bear species. American black bear ...

grizzly bear The grizzly bear (''Ursus arctos horribilis''), also known as the North American brown bear or simply grizzly, is a population or subspecies of the brown bear inhabiting North America. In addition to the mainland grizzly (''Ursus arctos horri ...

moose The moose (in North America) or elk (in Eurasia) (''Alces alces'') is a member of the New World deer subfamily and is the only species in the genus ''Alces''. It is the largest and heaviest extant species in the deer family. Most adult mal ...

wolf The wolf (''Canis lupus''; : wolves), also known as the gray wolf or grey wolf, is a large canine native to Eurasia and North America. More than thirty subspecies of ''Canis lupus'' have been recognized, and gray wolves, as popularly u ...

, black-tailed deer, mountain goat,

otter Otters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic, or marine, with diets based on fish and invertebrates. Lutrinae is a branch of the Mustelidae family, which also includes wea ...

wolverine The wolverine (), (''Gulo gulo''; ''Gulo'' is Latin for "gluttony, glutton"), also referred to as the glutton, carcajou, or quickhatch (from East Cree, ''kwiihkwahaacheew''), is the largest land-dwelling species of the family Mustelidae. It is ...

, and marmot. Birds inhabiting this ecoregion include

arctic tern The Arctic tern (''Sterna paradisaea'') is a tern in the family Laridae. This bird has a circumpolar breeding distribution covering the Arctic and sub-Arctic regions of Europe (as far south as Brittany), Asia, and North America (as far south a ...

spruce grouse The spruce grouse (''Canachites canadensis''), also known as Canada grouse, spruce hen or fool hen, is a medium-sized grouse closely associated with the coniferous boreal forests or taiga of North America. It is the only member of the genus ''C ...

, ptarmigan, and

gull Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century, m ...

. The isthmus of the

holds special ecological interest as region where species from differing ecoregions intermix.

Threats and preservation

Human-caused

climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...

has dramatically increased the rate of glacial retreat within this ecoregion, even with the counterbalance of naturally heavy snowfall. Threats to wildlife include the loss of land area to sea-level rise, scouring of river beds by heavy snowmelt, saltwater intrusion into bodies of freshwater, and

pollinator decline Pollinator decline is the reduction in abundance of insect and other animal pollinators in many ecosystems worldwide that began being recorded at the end of the 20th century. Multiple lines of evidence exist for the reduction of wild pollinator ...

. Other threats include

logging Logging is the process of cutting, processing, and moving trees to a location for transport. It may include skidding, on-site processing, and loading of trees or logs onto trucks or skeleton cars. Logging is the beginning of a supply chain ...

old-growth forest An old-growth forestalso termed primary forest, virgin forest, late seral forest, primeval forest, or first-growth forestis a forest that has attained great age without significant disturbance, and thereby exhibits unique ecological featur ...

s and

mining Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic via ...

Protected areas

Some of the largest protected areas of this ecoregion include: *

Atlin Provincial Park and Recreation Area Atlin may either be: *Atlin Lake, one of British Columbia's largest lakes *Atlin, British Columbia, a town in the far northwest of British Columbia, named for the lake, centre of a Klondike-era gold rush *Atlin District, the name for the region inc ...

* Chugach State Park * Glacier Bay National Park and Preserve * Kluane National Park and Reserve *

Tongass National Forest The Tongass National Forest () in Southeast Alaska is the largest U.S. National Forest at . Most of its area is temperate rain forest and is remote enough to be home to many species of endangered and rare flora and fauna. The Tongass, which i ...

* Wrangell–Saint Elias Wilderness

References

External links

* {{WWF ecoregion, name=Pacific Coastal Mountain icefields and tundra, id=na1117 Ecozones and ecoregions of British Columbia Ecozones and ecoregions of Yukon Nearctic ecoregions Tundra ecoregions