Montane Cordillera

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Location and introduction:
When we think of mountains in Canada, almost everyone thinks of the Geography of the Montane Cordillera. Almost all of southern British Columbia and a portion of southwestern Alberta are contained within this ecozone. With an area of approximately 405,000 square kilometers, it extends from the eastern slopes of the Rockies in Alberta to the western edge of the Pacific Coast Mountains. It consists of a ring of mountain ranges surrounding large interior plateaus. It is shown in the red area in the map below.

Figure 1: Location of ecozone.

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Landforms:

Percentage of total area of ecozone (by area):

Mountains 51
Plains 2
Hills 6
Plateaus 35
Valleys 6


This region originated as a flat plain near the intersection of the Pacific and North American plates. When these two plates collided, they uplifted the rock through faulting to produce mountain ranges. The region underwent multiple events resulting in multiple separate systems. The Cordillera is also subject to volcanism resulting from the subduction of the Pacific Plate. During the Ice Ages, the region was covered in glaciers sometimes up to 2.5 km thick, eroding away many valleys and plateaus, then forming glacial deposits (such as moraines) when they receded.

Table 1: History of the Montane Cordillera

ERA
PERIOD
Epoch
Geologic History
CENOZOIC
Quaternary
Holocene

Pleistocene
Late
Up to four glaciation events resulting in an ice dome covering everything below 2500 m
Early
Tertiary
Neogene
Pliocene
Late
Uplift occurred producing the Coast and Cascade Mountains
Early
Miocene
Late

Middle
Early
Uplift occurred producing the Rocky Mountains
Oligocene
Late
Early

Paleogene
Eocene
Late
The ecozone was a plane with scattered hills, and was very uniform
Middle
Early
Paleocene
Late

Early


Rocks and minerals:

Sedimentary rocks which have been uplifted to form mountains, through the process of faulting, form the Cordillera. The valleys and some other areas are formed of glacial deposits. There is a wide variety of mining, with products including precious metals, industrial minerals, and coal.


Climate:

The ecozone’s climate is extremely varied depending on location. Areas west of the Coast Mountains have a high rainfall and a primarily polar-maritime climate due to orographic precipitation, resulting in up to 1500mm of rainfall on the western face of the mountain range. However, the area of the ecozone from the Coast Mountains eastward is an arid, polar-continental region receiving only 300mm of precipitation in the south and 500-800 mm in the north. The Rocky Mountains also experience orographic precipitation on their eastern face, resulting in 1200 mm of annual precipitation. Temperatures range from an average annual temperature of 0.5 o C in the north to 7.5 o C in the south, and also decrease as altitude increases.

Climograph 1: Banff National Park

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Vegetation and Soil:
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The vegetation is extremely varied depending on location and altitude. Mountain ecosystems include lichens, herbs, and shrubs, while the sub alpine areas contain far larger flora such as Lodgepole pine, Alpine Fir, and Engelmann spruce. The growing season is usually 140-240 days depending on location. The southern valleys can be used as orchards or vineyards, and forestry is the ecozone’s leading industry. The area tends to have poor acidic soils, but there is a wide variety.


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Trivia:
This area has lots of tourism. It contains some of the best mountains for skiing in Canada, such as Lake Louise/Banff and Whistler Blackcomb, the site of the 2010 Olympic alpine events. It has a pristine wilderness and many national parks such as Banff, Glacier, and Jasper National Parks. Other than tourism, most jobs are related to logging the pine forests. The population is moderate with 2,744,467 in 2001 and a population density of 4.27 people/km2.

Test questions:
1. The ecozone was originally plains until it:
a) was covered in glaciers
b) started faulting
c) was covered in forest
d) became an ocean

2. Lodgepole pines are incredibly rare in the ecozone. True or false?

3. Explain what the climatic differences are between the Coast Mountains and Rocky Mountains.

4. What, in your opinion, is the most important factor in the geology of the ecozone?

5. If you had to chose a location in the ecozone to place a ski resort, where would it be and why?





Sources:



http://ecosys.cfl.scf.rncan.gc.ca/classification/classif05-eng.asp

http://www.naturewatch.ca/eman/reports/publications/99_montane/plants/intro.html

http://canadianbiodiversity.mcgill.ca/english/ecozones/montanecordillera/montanecordillera.htm

http://www.pc.gc.ca/apprendre-learn/prof/itm2-crp-trc/pdf/ecozone11_e.pdf

http://www.statcan.gc.ca/pub/16-201-x/2006000/4113960-eng.htm


http://www.eldoradocountyweather.com/canada/climate/banffclimate.html