Major Life Zones, or Ecoregions Within The Central Canadian Rockies

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1 EDUCATORS IN RESIDENCE OVERVIEW Major Life Zones, or Ecoregions Within The Central Canadian Rockies There are 3 distinct communities of plants in this region of the Canadian Rockies: Montane Forest Sub-alpine Forest Alpine tundra or meadows These distinct communities of life are defined by multiple factors including light, temperature, moisture, aspect, and exposure to wind. Elevation affects most of these factors, which explains why it is a good indicator of each ecological region. In many respects gaining altitude reflects the climate found in higher latitudes. The subalpine represents a growing season similar to the boreal forest of northern Canada. The alpine meadows bear a striking resemblance to the arctic tundra. Staring into a blizzard on top of the Columbia Icefield in January isn t too different

2 from surviving a storm near the magnetic north pole in April. These three landscapes offer rich and very diverse life zones that offer experiences that are accessible to us all. Montane Forest The montane forest is well represented in the lower valleys such as the: Athabasca valley from the east gate of Jasper to Athabasca Falls, around the North Saskatchewan River Valley as it leaves Banff through the Kootenay Plains, Bow Valley from east of Canmore to near the base of Castle Mountain The low valley bottom in Kootenay close to the Columbia Valley The valley floor in Kananaskis Country from entering the mountains to Peter Lougheed Provincial Park. The montane forest accounts for only about 7% of Jasper National Park and even less for Banff, but represents the best plant and wildlife habitat in the region. For about six months of the year the area is frost free and the climate is generally mild. Average temperatures (in Celsius) are: Daily July high 22 Daily Jan low -15 Annual precipitation 40 cm Days above freezing 164 (for a 24 hr period) In general the climate is a bit cooler, but very similar to that of Edmonton and Calgary. This is the most diverse region for plants and animals inside the Rocky Mountainl parks. The mild climate allows many species to flourish creating a fairly rich biodiversity (diversity of life). Most of the wetlands, grasslands, and open canopy forest are found here. Plants that are good indicators of montane forests are:: Douglas Fir Trembling Aspen Balsam Poplar Wild Rose Common mammals in the montane forest include: Mule Deer White Tailed Deer

3 Wapiti (elk) Wolves Bears (although many have been pushed out of the montane due to human pressures) The health of the montane and animals using it is closely tied to regular low intensity fire. Historically fire burned regularly in this region creating a mosaic patchwork of different aged forests and grasslands. Prior to 1920 it is estimated that at least 60 km2 of Jasper burned every decade. Most of the fires occurred in the montane, with any given area burning every 5-25 years. The average size of a fire was ha. These regular burns kept grasslands open and prevented lodgepole pine from invading aspen forests. Nutrients are freed from the burned plants and provide a rich bed for new lush vegetation to grow. Since 1920 fire control inside Banff and Jasper has been so successful that less than 1 ha burns in the parks every decade. This has led to a decline in habitat and a build up of wood in the forest. Instead of small low intensity fires there is a serious risk of a large severe fire that could cause widespread damage. To reduce the risk, and to restore fires natural process within the forest, park wardens have begun a cautious program of small prescribed fires. The Yellowstone fire (which burned 2/3 of the park down in 1988) is a good example of what happens if fires are suppressed for too long. Another issue is human activity. Both Banff and Jasper town sites are situated in montane forest. Highways run through almost every montane forest in the national parks. The most essential habitat for many of species living in the mountains is also the region that is increasingly fragmented and degraded by towns, roads, and heavily utilized services. As the elevation increases, temperatures generally decrease at a rate of 20 Celsius for every 300 metres. At around metres (depending on the source) the climate is too cold for many of the montane species to survive. Above is the sub-alpine forest. Sub-Alpine Forest From about ( ) to ( ) metres on high valleys and mountain slopes lies the sub-alpine forest. This is a cooler life zone or region with a shorter growing season and longer winters. Common plants in this region include: Sub-alpine fir Larch (Bow Summit and south) Engelmann spruce Labrador tea Mossy forest floor

4 Common animals are: Pine martens Mountain caribou (not common but clearly associated with the sub-alpine forest in winter) *At time of writing the mountain or woodland caribou is believed to have recently been extirpated in Banff National Park. Spruce grouse Pika (in rock piles or moraines near open meadows near treeline) The sub-alpine forest is not as diverse as the montane region, but covers about half of the central Canadian Rockies. Fire plays a smaller role here with burns occurring about every 100 years. These tend to be larger more intense fires than found in the montane environment. Avalanches can play a significant role in opening up the forest on moderate to steep slopes. In the summer these open slopes are often covered in plants and shrubs that provide good forage for species such as grizzly bears. As the elevation increases life becomes increasingly difficult for trees and they become dwarfed and stunted. At a vague barrier known as tree line, the forests end. The small tortured limbs of the last trees are called kruppelhoz (crippled wood). Above this lies the alpine life zone. Alpine Life Zone Life above metres is not particularly pleasant. The growing season is often only days. Frost can occur on any evening, and snow may fall even in summer. The alpine environment occupies about 40% of the region, most of it unsuitable for vegetation. Many of the plants living at this elevation will require years or even decades before their first bloom. What little lives up here is very fragile. Higher in the alpine zone the plants diminish until there are only lichens and rock. Eventually even the lichens disappear, leaving only snow, ice, and the rock. Common plants include Purple Saxifrage Moss Campion Alpine Cinquefoil Animals found in the alpine zone include: Hoary Marmots

5 Ptarmigan Mountain Goats Mountain Caribou (in summer ) The exposed rock high up on the mountains, permanent snow caps, glaciers, and icefields are all examples of the alpine life zone. In many ways this landscape is comparable to arctic conditions in northern Canada. Many of the same species can be found in both regions. In many ways the alpine life zones on top of the higher mountains are tiny arctic islands that became stranded as the last major ice age retreated 11,000 years ago. Protecting Ecosystems in Alberta, A Survey of Government Mechanisms, prepared by Susan Bramm, Environment Council of Alberta, 1992 GIS map, Jasper National Park, Banff National Park