The Ever Changing Forest
Douglas Fir trees are the climax species that will grow to dominate the forest if there are no disturbances, even on the south-facing slopes, where Ponderosa Pine thrives. If a Ponderosa Forest becomes too thick and shady, the Ponderosa seedlings will not grow healthy. The Douglas Fir seedlings will grow strong in the shady, overgrown conditions and will eventually crowd out the Ponderosa.
Aspen trees are a pioneer species that are quick to grow after a disturbance such as an avalanche or fire. Aspens have suckering root systems that can grow or die back according to sunlight or competition from shade-loving plants. After a forest fire creates a clearing in the firest, Aspens begin to sprout from the root system that remains alive undergrown, waiting for a sunny opportunity to grow.
The Land of Few Trees
The Great Plains that stretch to the eastern horizon are inhospitable to trees. The sandy and clay soils do not hold enough water to support large plants such as trees. Plains Cottonwood trees mark the presence of water on the harsh, dry grasslands. Trees naturally grow along creeks and rivers like a green ribbon across the prairies.
Today, the native trees are hard to find in the urban forest that has grown up with our city at the foot of Pikes Peak. Since 1972, city foresters and citizens have been planting trees, and with the help of irrigation water, our hot, dry grasslands have shade.
Trees are Attracted to Rocks
Water seeps into the fractures and spaces among rocks. Trees naturally cover the bluffs, foothills and mountains that mark where Colorado Springs lies at the edge of the high plains. The mountain cañons were once amoung the few green and shady places to be found near our city. Growth patterns that change with elevation and water supply are easily seen here. Visitors may notice how the cool north-facing and the hot south-facing slopes of the mountains support different variations of trees, shrubs and ground cover. North Cheyenne Cañon Park is an Ecotone
Plant and animal diversity is abundant in this mountain park where 3 different lifezones are intermixed in this area defined as an ecotone. The creek suports a moist riparian lifezone that flows from the high elevation mountaine lifezone down the steep Cañon to the lower elevations of the foothills lifezone.
Ecology of a North Facing Slope
There is more moisture on the north side of a mountain, because snowfall lasts longer in shade locations, slowly melting into the soil. The cool temperatures also reduce evaporation of rainwater. You can feel the shade created by the trees and listen to the chatter of the little Chickaree Squirrel or the beautiful blue-colored Stellers Jay.
Fir Trees Love the Shade
Douglas Fir and White Fir trees tend to grow close together and the crowns of their treetops grow into a closed campoy forest with patchy sunlight reaching the ground. The triangular shape of a Fir's branching pattern makes it very efficient at collecting sunlight while growing close to other trees. Mosses, mushrooms and moisture-loving flowers are found in these cool, shady places.
Survival of the Fittest
Each tree must compete for sunlight. Young Fir trees are able to grow under the shade of their parents for a few years. Many seedlings and saplings can been seen growing within inches of each other. Eventually, dominant trees will live and weaker trees will die out because they cannon compete for water and sunlight. You can notice that big trees are spaced further apart than the little trees.
Seedlings--are up to 3-feet tall.
Saplings--are between 3- and 10-feet tall.
Pole Size--trees have a diameter between 6 and 10 inches wide.
Standard Size--trees have a diameter between 10 inches and 2-feet wide.
Veterans--have a trunk that is over 2-feet wide. Think about tree years compared to human years. You can roughly estimate the age of seedling and sapling trees by counding the spaces in-between whorls of branches they produce each summer.
Ecology of a South Facing Slope
The sunny southern slope of a mountain is hot and dry. Water is scarse because of intense sun and rapid evaporation. On Cheyenne Cañon's south facing slopes you can feel the heat of the sun and smell the sweet red bark of a Ponderosa. You can look for a black or gray Alberts Squirrel with long tufted ears. The long-tailed black and white Magpie has blue-green colored feathers if the light is right.
Ponderosa Pines thrive on southern slopes. Ponderosa have a deep, moisture-seeking taproot, and a broad, rounded, branching pattern for the crown. A healthy Ponderosa forest is open and sunny because trees space themselves far apart to avoid competition for precious water. Other common plants found in this sunny forest are Scrub Oak, Yucca and Kinnikinik. Fire Survival
The Ponderosa has thick, insulating bark that protects it from small fires. The low branches of trees eventually die and fall off because they do not collect much sunlight. This self-pruning of an old branch also helps trees survive small grass fires that do not reach high branches of the crown. The Fires of Cheyenne Cañon
1840s--A trapper named George Ruxton documented a terrible fire in his journal. He described Cheyenne Mountain as being "invaded by the devouring element," of flames one night, and the skies glowed for 14 nights longer as the mountains 40 miles further west, (to Wilkerson Pass) burned.
1890--The Colorado Springs Gazette reported on Sunday, January 26, of a fire from the day before. "Old Cheyenne Mountain, standing out bold and alone from the range, was a seething mass of fire. It was grand, but pitiable to those who realized what such a fire means."
1950--The last major fire was also in January. On the 17th, the range from Cheyenne Mountain on toward the south was in flames. The US Army sent troops to fight the fire. Seven Camp Carson soldiers lost their lives working to bring the inferno under control.
The Forest has Layers of Life Tree Canopy
The upper layer includes the leaves and branches of tall trees such as Douglas Fir, White Fir, Ponderosa and Aspen.
The middle layer includes shrubs like Boulder Rasberry, Rocky Mountain Maple and Chokecherry.
The ground layer includes grass, Poison Ivy, and wildflowers, such as Shooting Star, Mariposa Lily and Columbine.
The unseen world includes burrows, roots and wormholes where fungi and microorganisms help make soil rich by decomposing dead plants and animals.
Buffalo Creek originates from natural runoff on Mount Rosa. It converges with North Cheyenne Creek below the Silver Cascade falls and beyond the ridge that separates it from North Cheyenne Creek. In the Colorado's dry climate, water is our most precious resource. This wet ribbon of land is essential for all wild animals. In the Cañon, look for a natural spring flowing from the middle of the trail or seeping from the rocks. Notice the abundance of lush-green plant life, including Wild Roses and Aspen.
Survival of the Veterans
Massive tree trunks mark the spot where you can enjoy the shade of giants. The veteran size of the fir trees in this moist pocket among boulders and waterfalls does not mean they are ancient in age. Trees can grow to be very large if they have plenty of water and sunlight. Photographs taken 100 years ago show sapling and pole size trees at this site.