| Boreal Cordillera | |
|---|---|
 Yukon Southern Lakes ecoregion of the Boreal Cordillera ecozone | |
| Ecology | |
| Borders | |
| Geography | |
| Area | 467,870 km2 (180,650 sq mi) |
| Country | Canada |
| Provinces | |
| Climate type | Subarctic |
TheBoreal Cordillera Ecozone, as defined by theCommission for Environmental Cooperation (CEC), is a Canadian terrestrialecozone occupying most of the northern third ofBritish Columbia and southern half ofYukon. Within it is foundKluane National Park and Reserve, and a small portion of the southern range ofNahanni National Park Reserve.[1] Most of the area's population is based in the city ofWhitehorse, and it contains most of Yukon's population. The portion in British Columbia is barely populated.[2]
The main economic activity ismining, particularly ofgold, which discovery in the region led to theKlondike Gold Rush.[3] In addition to the area's richmineral deposits, active industries exist inforestry andtourism.[4]
Thismountainous ecozone is between theMontane Cordillera Ecozone to the south-east and theTaiga Cordillera Ecozone to the north. The three zones contain theCanadian Rockies. To the east are theTaiga Plains, and to the west isAlaska, though the ecozone is also adjacent to narrow strips of thePacific Maritime. It is characterized by tall peaks and extensive plateau.[5] The northern plateaux within the ecozone have a fairly gentle terrain, broken by numerous watercourses running through them, and are separated by widevalleys and theirlowlands.[4]
Just over 15% of the Boreal Cordillera, or roughly 73,320 km² consists ofwetlands, of which 92% is treed wetland.[6] It covers a total area of 471,400 km², with 241,240 km² offorest cover, of which 78.6% issoftwood, 17.8% is mixedwood, and 3.6 ishardwood.[6] The spruce beetle has been proliferating since the 1990s, and has destroyed vast areas of the spruce forest. The ecozone contains four forest regions - tundra, sub-alpine, coast, and boreal.[7] There is also concern that the softwood harvest in southeastern Yukon does not have adequate natural regeneration.[8]
This ecozone can be further subdivided into four ecoprovinces:[9]
The interior intermontane plateau receive about 400 mm of annualprecipitation, much less than the 1000 to 1500 mm levels in the eastern mountains, and the even higher levels in the western mountains.[5]Snowfall accounts for 35 to 60% of all precipitation.[10] Winters are long and cold, with January mean temperatures between -15 °C and -27 °C. Summers are warm but short, with July mean temperatures between 12 °C and 15 °C.[5]
Alpine weather is more typical beyond thetree line at elevations above 1000 m, where frost can develop year-round.[10] Average temperatures here remain below freezing for most of the year, and snowfall accounts for at least 70% of precipitation.[10] Permafrost is typical in these regions, allowing for the growth of onlyshrubs,mosses andlichens.[11]
Sudden violent storms may occur in the area during the summer, usually due to moist air masses arriving from thePacific Ocean.[10] Usually, however, the Pacific moderates the climate in this ecozone.
A number ofprotected areas have been established to protect representative and/or significant portions of this ecozone. These includeAsi Keyi Territorial Park,Kluane National Park and Reserve,Mount Edziza Provincial Park,Spatsizi Plateau Wilderness Provincial Park, andTatshenshini-Alsek Provincial Park.