Mountain flora

Edelweiss and gentian are two of the best known Alpine flowers, but many others are also perfectly adapted to this hostile environment.

The bright colours of the mountain meadow flowers are not there by chance; they are vital to their survival and reproduction. In the first place, the pigments protect them from the intensive ultra violet rays found at high altitude. Secondly, weather conditions often prevent insects from flying, so the plants cannot afford to waste a moment of precious pollination time. The colours attract the insects without which they could not reproduce. They have to be quick about it too: the specialised plants must produce their seeds before the haymakers move in for the first harvest of summer.

Plants that share their habitat with grazing animals have quite different problems. Tasty plants will get eaten before they can produce seeds, so those with tough, prickly leaves stand a better chance. Being trampled is scarcely better than being eaten as far as the chances of reproduction are concerned, so delicate plants like orchids will only survive close to rocks or cliffs away from heavy hooves. Other tender plants have strongly developed root systems which help them withstand the ravages of hungry animals.

As glaciers melt, they leave behind unstable, stony ground, with no water and no nutrients. And yet within just a few years, specially adapted plants manage to colonise this apparently hostile terrain. Mosses move in first, producing a thin layer of humus when they die, which gives a chance to the saxifrages and toadflaxes to take root. The greatest problem for these pioneers is not so much the lack of soil as the constantly moving ground: even the tiniest plants anchor themselves with roots that can be a meter long, and their underground shoots are always ready to put out new sprouts if they find themselves buried by rolling stones. This is also the habitat of the world's smallest tree, the dwarf willow, which keeps its trunk below the surface, leaving just a few small branches poking out. Not only does this strange way of growing keep it warm, but shelters it from the wind, and thus prevents water loss.

Plants growing on rock faces have developed various strategies to deal with water shortage. The poor soil is unable to retain moisture, and the sun beating down on the cliffs soon removes what is left. Strong winds, common at high altitude, would dry out the leaves of normal plants. But the ones here have developed different coping strategies. Some are covered in hairs, which deflect part of the sun’s rays, and also form a layer of air which traps moisture, while others have a waxy coating. Succulents store water in their fat leaves, and many form rosettes so that the leaves all shade each other. Yet other plants increase their chances of withstanding drought by growing close to the surface, which protects them from the wind. And of course, many of them combine several of these strategies.

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