Between timberline and summit lies a delicate yet tenacious floral world
Text by Graham Osborne
Nature saves some of her most spectacular displays for the harshest of environments. Tossed by incessant winds, this "garden of the gods" clings to the steep slopes of the Selkirk Mountains in Southeastern B.C. Among the species in this alpine meadow are Indian paintbrush, purple lupines and tall, white Sitka valerian (wild heliotrope).
THE SNOW has not yet left the mountain meadows when the first green shoots appear, nipping at the heels of the retreating snows and chasing the remnants of winter high into the icefields. Bright yellow glacier lilies and showy white avalanche lilies lead the mid- to late-June floral insurgence, followed closely by the creamy flower cups of western anemones.
By mid-July the rich and varied shades of Indian paintbrush vie with purple lupines and yellow arnica. And as August nears, the meadows reach a crescendo of colour and abundance. In the showiest of displays, great seas of blossoms stretch for acres, belittling the accomplishments of even the most ambitious human gardeners.
Yet these most delicate and brilliant of nature's displays occur not in mild and clement climes, but amid a landscape of ice-ravaged mountains and unforgiving elements. This is a land of contrasts and unlikely cohabitants, the land of the alpine meadow.
At first glance plants seem merely foolish to attempt to live here. Many areas remain snowbound for eight months or more. And while the snow pack provides an insulating blanket against winter's cold, and supplies the moisture on which these meadows thrive, the alpine growing season is limited to a few frenzied months. Even then, heavy frosts are a threat at any time of the year, and desiccating alpine winds blow incessantly through the meadows.
But these flowering species have evolved surprisingly sophisticated adaptations to help them deal with environmental stresses. Some have developed an internal antifreeze as protection against killing frosts. Some have thick, leathery leaves, or a coating of tiny hairs, to cope with the endless winds. And others have clever design features, like the western anemone's cup-shaped flowers that can trap solar energy and raise the temperature of the reproductive structures by several degrees.
The term "alpine meadow" is often applied to any meadow on a mountain, but in a strict sense, the alpine zone extends only from the barren, rocky mountaintops down to the timberline, that rather nebulous "line" that defines the upper limit of tree growth. Below it, the subalpine begins, characterized by patchworks of meadow and forest in its upper reaches, and gradually thickening to dense, closed stands of Engelmann spruce, fir and other coniferous species.
Latitude largely determines at what elevation the alpine zone begins. For example, at the northern extremity of the Rockies in northern B.C., the alpine zone begins at about 1,200 metres. Yet at the southern end of the Rockies in New Mexico, you have to climb as high as 3,600 metres to reach alpine meadows. Despite this variation in elevation, most alpine meadows tend to look very similar. Many of the same species found flowering in southern B.C. also grow as far north as northern B.C. and Alaska and as far south as California.
But while these hardy alpine survivors can withstand and adapt to the rigors of mountain life, they are vulnerable to outside disturbance. Subalpine and alpine regions are widespread in Western Canada, but areas of truly exceptional floral displays are not. Some are protected to some degree in our parks and ecological reserves, but perhaps the finest flower meadows in the world remain menaced by cattle grazing, mineral exploration, all-terrain vehicle traffic, and careless hiking. Even a misplaced footstep can upset the delicate balance of soil and moisture that allows these plants to thrive at such elevations. There is a fragile web of life in this mountain environment, and even the adage "leave nothing but footprints" may be an inadequate warning.
