|McNeil Point on Mount Hood|
Yet, the beauty of these trees is forged in adversity. It is a wonder that conifers can survive at these high elevations where they can be completely covered in deep snow, where they can be blasted with ice crystals in fierce winds, and where their branches and even their roots can be frozen by severe winter temperatures. To survive here they must adapt. The short branches of subalpine fir and Pacific silver fir keep them from breaking when covered in snow. Mountain hemlock branches are bendable and small trees that are covered with snow bend to the ground and pop back up in summer. The drooping branches of Alaska cedar just don’t collect much snow. On the other hand, many species depend on deep snow to protect their roots from freezing. The snow also protects trees from high winds that would blast them with ice crystals.
|Mountain hemlock and whitebark pine|
Contrary to common sense, it is not only the cold of winter that is destructive to alpine conifers. It is also … wait for it … heat. Conifers prepare for cold weather in the fall when temperatures begin to drop below freezing. If needles do not mature in the summer, they can be damaged by frost. But warm weather can dry out the new growth in winter, especially when it is windy or sunny. This drying or “winter desiccation” can be fatal to needles that have not had a chance to mature in summer. This hardening protects the needles, enabling them to retain their moisture. You can look at damaged needles and tell whether they were damaged by frost or winter desiccation. Frost damaged needles shrivel and then turn black. Needles damaged by winter desiccation turn orange-brown. (Arno, p. 58)
Late summer is a great time to visit alpine areas. The snows have melted, and wildflowers are taking advantage of their brief summer and blooming in abundance. These parklands of life living on the edge are unmatched in stunning beauty themselves. Also, the view there is often framed by picturesque, snow-capped mountain peaks.