Hiking the tundra communities trail in Rocky Mountain National Park I appreciated the classic engraved interpretive signs. Even better, the text is almost poetry!
The alpine tundra is a land of contrast and incredible intensity, where the sky is the size of forever and the flowers the size of a millisecond. - Ann Zwinger
Land Above the Trees. You are entering a special world. Life here is strained by scouring winds and bitter cold, and only the hardiest survive.
The march of forests up the mountains is abruptly halted by cool summer temperatures. At their upper limit, trees may grow only an inch in diameter every one hundred years. On the tundra, snow can fall any day of the year. Nighttime temperatures often dip below freezing. Only plants adapted to this harsh environment can surviye where the growing seasons last six to eight weeks each year.
Each winter, hurricane force winds in excess of 100 miles an hour drive snow across the tundra. Thirty foot drifts form in places, covering plants and animals with a protective, insulating blanket. Where snow is blown free, the winds rob heat and moisture from vegetation and blast every exposed leaf and twig with particles of ice and sand.
In the distançe, the tundra appears unvaried and uniform. But closer inspection reveals an intricate patchwork of alpine plant communities. These were created by differences in snow cover, moisture, and soils. Unless disturbed, this thick turf of grasses andsedges will remain unchanged for hundreds of years.
Many alpine plants contain anthocyanin, a chemical “antifreeze" that converts sunlight into heat. Plant hairs provide a furry coat that reduces the loss of heat and moisture. These hairs also protect plants from the intense ultraviolet radiation that is twice what it is at sea level.
Winter winds sweep this fellfield or "field of stone" free of snow. This alpine desert may therefore receive as little as two inches of moisture each year. Dense cushion and mat plants survive best here; their moisture-seeking roots penetrate four to five feet into the rocky ground.
In wet areas, buried rocks are churned about as moist soil repeatedly freezes and thaws. Rocks are squeezed to the surface, where they form rock streams, stripes, garlands, or polygons.
Ice shaped Trail Ridge, even though glaciers never reached thishigh. The ground beneath your foet was permanently frozen during the Ice Age, and only the surface layers thawed in summer, Water trapped in the earth above the ice caused the supersaturated soil to creep down the mountain in ridges, or solifluction terraces.
In wet areas, buried rocks are churned about as moist soil repeatedly freezes and thaws. Rocks are squeezed to the surface, where they form rock streams, stripes, garlands, or polygons.
These gentle, rolling mountaintops are remnants of an ancient plain, lifted into the sky by tremendous mountain building processes. Rivers of ice a thousand feet deep once filled Forest Canyon to your right.
Glaciers ripped away the rock, widened the valley, and quarried the basins now filled with alpine lakes.
Lichens also help erode rock. These multicolored miniature plants produce weak acids that gradually dissolve the cement binding minerals together. They are one of the first plants to pioneer an area after glaciers retreat. Some species live for thousands of years.
White-tailed ptarmigan are also supremely adapted to alpine climates. These chickenlike birds have feathered feet that act as warm snowshoes. Ptarmigan often wait out winter storms in miniature snow caves. Their ability to turn white in winter and mottled brown in summer makes them masters of camouflage.
If you're quick, you may catch a glimpse of small, rabbitlike animals scurrying among the boulders. Pikas are the farmers of the tundra. They harvest plants: throughout the summer and store them in "haystacks" under rocks for their winter food supply. Deer mice, meadow voles, shrews, pocket gophers, and weasels are other small dwellers of this community.
