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Yukon Interior dry forests

Yukon Interior dry forests

Kusawa, Yukon Territory, Canada Photograph by J. Peepre Kusawa, Yukon Territory, Canada Photograph by J. Peepre
This article has been reviewed by the following Topic Editor: Mark McGinley

This ecoregion lies predominantly within the Yukon Territory. A small portion dips into extreme northwestern British Columbia. This ecoregion contains much of the human population in the Yukon, including parts of most major highways in the territory.

The climate in this ecoregion in the Yukon interior can be characterized as cold and semiarid. Mean annual temperature is around -3°C, mean summer temperature is 11°C, and mean winter temperature ranges between -16.5°C and -19°C. The southern portion of the ecoregion lies within the rain shadow of the St. Elias Mountains. Mean annual precipitation is in the range of 225-400 millimeters (mm), increasing with elevation and in the north-east.

The Yukon Plateau is the dominant physiographic feature. It is composed of groups of rolling hills and plateaus separated by deeply cut, broad valleys. Elevations in this ecoregion are generally above 1000 [meter|meters]] (m) above seal level, with some smaller peaks in the south. Low-ice-content permafrost occurs in a sporadic discontinuous pattern here.

Biological Distinctiveness

White and black spruce (Picea glauca and P. mariana) form the most common forest types. Lodgepole pine (P. contorta) often invades very dry sites and burnt areas. South-facing slopes at low elevations are often characterized by grassland communities. Scrub birch (Betula sp.) and willow (Salix spp. ) occur up to the tree line, which is usually defined by the presence of alpine fir (Abies lasocarpa). In the colder alpine regions, mountain avens (Dryas hookeriana), dwarf shrubs, forbs, grasses, and lichens constitute the main vegetative cover. Due to the relatively dry interior climate, forests are frequently renewed from recurring natural fires such that young successional communities are most common.

Characteristic wildlife species include caribou (Rangifer tarandus), moose (Alces alces), mountain goat (Oreamnos americanus), Stone’s and Dall’s sheep (Ovis dalli spp.), grizzly and black bear (Ursus arctos and U. americanus), wolf (Canis lupus), coyote (Canis latrans), beaver (Castor canadensis), ground squirrel (Spermophilus parryii), hare (Lepus spp.), raven (Corvus corax), ptarmigan (Lagopus spp.) and golden eagle (Aquila chrysaetos).

This ecoregion contains one of the most northern areas on the continent with grassland communities. The juxtaposition of these grasslands with northern boreal forest creates an unusual association of plant communities.

Conservation Status

Habitat Loss and Degradation

It is estimated that approximately 75 percent of the ecoregion remains intact. Most of the disturbed habitat is considered to be altered, with only a small amount of area heavily altered. Factors leading to habitat loss include forestry and mining activities, urban growth around Whitehorse, and major transportation corridors.

Remaining Blocks of Intact Habitat

Most of the ecoregion, particularly the uplands, can be considered as intact habitat. Valley bottoms have been most widely developed.

Degree of Fragmentation

Habitat fragmentation in this ecoregion has principally resulted from the construction of major transportation corridors through the lower elevations. Susceptibility is high for some species with seasonal migrations or movements between habitat types, especially large carnivores, woodland caribou and Dall’s sheep.

Degree of Protection

There are no large protected areas yet established in this ecoregion.

  • Charlie Cole Creek Ecological Reserve - southern Yukon Territory - 1.62 square kilometers (km2)
  • Nisutlin River Delta National Wildlife Area (not fully protected) - southern Yukon Territory - 5.28 km2

Types and Severity of Threats

Threats to biodiversity are increasing rapidly in this ecoregion. Timber harvesting has begun and is yet to be well-regulated or planned in the Yukon. Mining activity is significant in some parts of the ecoregion and a number of wildlife species are in serious decline. A government-sanctioned wolf kill has been occurring in this area for the past few years.

Suite of Priority Activities to Enhance Biodiversity Conservation

  • The highest priority activity is to establish a new protected area following the Kusawa Lake territorial park proposal.
  • Control programs for carnivores should be permanently ended.

Conservation Partners

  • Canadian Nature Federation
  • Canadian Parks and Wilderness Society, Yukon Chapter
  • Friends of Yukon Rivers
  • World Wildlife Fund Canada
  • Yukon Conservation Society

Additional information on this ecoregion

 

Disclaimer: This article is taken wholly from, or contains information that was originally published by, the World Wildlife Fund. Topic editors and authors for the Encyclopedia of Earth may have edited its content or added new information. The use of information from the World Wildlife Fund should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.

 

 

 

 

 

Citation

World Wildlife Fund (Lead Author);Mark McGinley (Topic Editor) "Yukon Interior dry forests". In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth November 14, 2008; Last revised Date July 27, 2012; Retrieved May 25, 2013 <http://www.eoearth.org/article/Yukon_Interior_dry_forests>

The Author

World Wildlife FundKnown worldwide by its panda logo, World Wildlife Fund (WWF) leads international efforts to protect endangered species and their habitats. Now in its fifth decade, WWF works in more than 100 countries around the globe to conserve the diversity of life on Earth. With nearly 1.2 million members in the U.S. and another 4 million worldwide, WWF is the world's largest privately financed conservation organization. WWF directs its conservation efforts toward three global goals: 1) saving endangered ... (Full Bio)

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