Rocky Mountains subalpine zone
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The Rocky Mountains subalpine zone is the biotic zone immediately below tree line in the Rocky Mountains of North America.
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[edit] Flora and fauna
In the North American Rocky Mountains, the region is characterized by a concentration of Subalpine Fir and Engelmann Spruce and generally the exclusion of trees found more commonly at lower elevations such as Aspen, Ponderosa pine and Lodgepole Pine. In other areas, Engelmann Spruce and Subalpine Fir mix with or give way to various pines, such as Whitebark Pine and Bristlecone Pine, other firs such as Douglas-fir and Silver Fir, and various junipers and other hardy species.
Due to harsh winters and a relative dearth of food sources, the subalpine harbors limited native animal species. While bears and the Cougar visit the subalpine, lynx, the Snowshoe Hare, the American Marten and various squirrels are among the few important native furred mammals. A few birds, such as the Mountain Chickadee and Stellar's Jay are commonly seen and heard in Rocky Mountain subalpine regions, with others such as owls, nuthatches and certain finches less obvious.
[edit] Climate
The climate of the Rocky Mountains subalpine zone is never warm, with summer highs reaching 75°F / 24°C on only the warmest days near the montane, and commonly failing to reach 60°F / 16°C near tree line; Frost may occur any day of the year. Although winter low temperatures may be warmer than those in nearby lower valleys, typically staying above −10°F / −23°C, prodigious snows blanket the region well into spring. Some drifts may linger into summer. Convectional precipitation, typically thunderstorms, often form rapidly and frequently drop graupel or hail. Although uncommon, hurricane-force winds may develop and cause massive destruction such as the Routt Divide Blowdown.
[edit] Books
- Benedict, Audrey D. (1991). A Sierra Club Naturalist's Guide: The Southern Rockies (1st ed.). San Francisco: Sierra Club Books. ISBN 0-87156-647-8.
