To understand the Present on the Basis of the Past
Earth History
4,5 Billion years ago a new planet was created in the universe, the earth. When the external crust of the originally fiery planet solidified, land and sea were born. This thin crust broke into approx. 20 greater and smaller islands floating on the liquid magma below. The slow movement of the islands led to dislodgements, to collisions and separations, pushing the edges upwards. Mountain ranges were created (the Alps, the Andes, the Himalayas). In the course of earth history the Euro-Asian continental plate and the climatic zones moved further south, causing the vegetation borders to shift as well: they moved north. Where 60 billion years ago subtropical forests stood, the Alps are found today. 2 million years ago the temperature fell globally resulting in the Ice Age.
The Ice Ages
During the Ice Age climatic catastrophes caused the tropical plants to die out in Europe. At the same time the alpine mountain range was created, i.e. new land without plant colonization. The development of alpine plants must be seen as a process of adaptation and transformation, lasting millions of years. Not only the external form but also the internal properties have to be adapted to the more arduous conditions in order to survive (e.g., the evolution of resistance to cold). Unfavourable, variable environmental conditions result in a change in the genetic makeup (genes) and the spontaneous generation of numerous new biotypes, creating new chances for survival. Many of the species we know, like the Alpenrose, Primula and Edelweiss are to be found in greater variety in the Asian mountains (Altai, Himalayas), so that we have to assume that they originate there. Pine, Yellow Genipi (Artemisia mutellina) and our famous Edelweiss, viewed as symbolic representatives of the Alps, are in fact immigrants.
During and after the ice ages, far-reaching plant migrations took place, to which the Alps owe many settlers. Perhaps only after the end of the last Ice Age 20.000 years ago mountain steppe plants from Central Asia migrated, e.g. species of the Naked Rush windy corner: Bellard's Kobresia (Elyna myosurides), Edelweiss (Leontopodium alpinum), Wormwood (Artemisia sp.), Alpine Saussurea (Saussurea sp.), Vetch - and Milk-vetch species (Astralagus sp, Oxytropis sp.). Even the Arolla Pine (Pinus cembra) migrated from a huge area in Southern Siberia to the Alps in geologically recent times.
In the course of the last millennium, man began to settle the inner alpine valleys and parts of the natural forests were cleared. Development through roads, funiculars, ski runs, and hotel buildings during the last 100 years has changed the original appearance of the Alps and its vegetation most substantially, so that we are forced to protect the remaining nature reserves for posterity. Global warming - generally caused by man - does not stop at the Alps. The glaciers melt, the borders of growth to vegetation are shifting upwards and the skiing seasons grow shorter.
|
|
| During the ice ages the Inner Alps might have looked like this. Single peaks overtop the glacier. Western Alps: photo taken from the aeroplane | Maximum glaciation of the Central Alps during thelast ice age. Ice free refuges are coloured green |