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Colorado Hiking   

Ecosystems                                         

Here's a brief stab at an inherently complicated subject - characterizing alpine ecosystems in terms of altitude. The elevation spans for these "indicator" plants are only approximate. In reality, they can be found at varying altitude ranges depending on local factors like precipitation, winds, sunlight, temperature ranges and history of fires over recent centuries.

Alpine tundra 11500 plus  Alpine tundra is what you get when it's too cold and windy for hardly any trees to survive. A stunted form of Engelmann Spruce can occur in this zone. High winds often desiccate this environment and it's mostly inhabited by small plants like herbs, lichens and mosses.
    Mountain goats like tundra areas, and bighorn sheep and elk are also found up there.

Sub-alpine Forest 9000-11500  Elk, mule deer, black bear, bighorn sheep, mountain lion, moose and mountain goats are found in this zone.

Engelmann Spruce 9000-11500 

Engelmann spruce can get large - exceeding 30 inches in diameter and 90 feet in height.  At  high elevations with severe winds,  the growth may be low and shrubby with some stunted trees.

Sub-alpine Forest cont.

Sub-alpine Fir 9000-11000  

Sub-alpine fir has a distinctive crown that is slender and spire-like - the uppermost part may have a diameter of less than 1 foot. The branches on the trunk go right to the ground. 

Native Americans used its needles to make hair tonic and ground-up needles were sprinkled on open cuts. Its resin was collected,  boiled and used as an antiseptic for cuts and as a tea for colds.

Sub-alpine Forest cont.

Lodgepole Pine 8500-10000

Lodgepole Pine is dependant on fire for reproduction. The cones of this tree remain closed until heated up. It often re-colonizes burnt ground.  If no fires occur, lodgepoles get replaced by other trees, such as firs and spruces. Lodgepole pine was traditionally used by native Americans in the construction of lodges. 

Sub-alpine Forest / Montane Forest 

Bristle Cone Pine 8000-11500 

Bristle cone pine is the most durable tree on earth. One in Nevada has been dated at  4,900 years. A Sierra redwood in northern California comes in second - a mere 2,300 years of age. Bristle cones can stand up to very hard conditions and are often contorted and gnarled in appearance.

Sub-alpine Forest / Montane Forest

Aspen 7500-10000

Aspens have a relatively short life span - about 120 years. They often form groves after a fire or avalanche has wiped out the conifers in a particular area. The aspen trees then provide shade for fledgling conifers, which eventually replace them. In the high mountains, instead of reproducing from seeds, aspen often do it through lateral root networks which produce shoots, which give rise to new trees. Tree groves produced by this lateral root system are genetic clones which wind up sprouting new buds and changing leaf colors at the same time, which amplifies the golden fall color effect.

The change from green to gold in the leaves usually starts in early September at the highest elevations, then works its way down for a couple weeks. The process depends on the weather, and varies from year to year.

Aspen trees often show scarring of their bark. During winter, elk, deer and other foragers often chew it to get at the soft inner bark. Elk and mule deer also rub their antlers against the trunks to shed velvet in autumn. Black bears mark their territory by clawing the trunks. If too much bark is removed or damaged, the trees will die.

Montane Forest / Shrubland 5500-9000  Elk, mule deer, black bear, bighorn sheep, mountain lion and moose are found in this zone.

Ponderosa Pine 6000-9000   

Ponderosa pines can reach heights of 180 feet, with diameters of 4 feet, though you won't easily find any like that nowadays. It has a pyramidal crown when young, maturing to a flat crown. The trees can age up to 600 years.

Montane Forest / Shrubland cont.

Pinyon Pine 5500-7000   

Pinyon Pines depend on a large root system for water. Tap roots can reach down 40 feet and lateral roots match that in extent. Because of this,  you don't see pinyon pines clumped together. The seeds or nuts of this tree ripen in October-November, and are very nutritious. Archeological work indicates they have been used for food for at least 6000 years. Navajo and Pueblo traditions both identify pinyon nuts as a food source for their ancestors. 

Juniper 5500-7000

Junipers can survive because their leaves, which are retained all year, are reduced to tiny, waxy scales covering the twigs and small branches. Native Americans use the juniper for medicine and ceremonial purposes and the berries for beads. They use the wood for hogans, wickiups, pit houses, utensils, firewood, prayer sticks, weaving tools and fence posts, and the shredded bark for bedding.

Short-grass Prairie Pronghorn antelope and mule deer are found on the prairie.

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