Universals in mountain habitats

When Lucien Febvre wrote, in 1922, that ‘il n'y a point une sorte d'unite de la montagne’, he was reacting against those followers of Ratzel who stressed the similarities found in the social and economic life of upland populations in order to demonstrate that analogous geographical conditions always entail analogous developments. If too strong an emphasis is placed on general similarities, he rightly argued, the various mountain areas are inevitably stripped of their distinctive history. Yet neither Febvre nor Vidal de la'Blache, the forerunner of geographical possibilism, would deny that in the mountains the impact of the natural environment on human populations is most dramatic and direct, especially in the high valleys. Nor would they dispute that mountain habitats are universally characterized by a certain number of major physical and climatic features.

The outstanding feature of any mountain habitat is of course altitude, which powerfully affects such climatic factors as air pressure and composition, insolation, winds, evaporation, humidity, precipitation, and above all temperature. It is well known that with the rise from the sea level into the upper regions of the atmosphere the temperature decreases. It was been calculated, for instance, that on the northern side of the Swiss Alps the mean annual temperature drops from about 8.5 C at 500m of altitude to 5.4 C at 1,100 m and to 0.3 C at 2,000 m.