ABSTRACT
On a global scale, plant life at high elevations is primarily constrained by direct and indirect effects of low temperature and perhaps also by reduced partial pressure of CO2. Other atmospheric influences, such as increased radiation, high wind speeds or insufficient water supply may come into play on a regional scale, but exert no globally uniform characteristics of high mountain systems (for climatological data see Lüdi, 1938; Fliri, 1975; Lauscher, 1977; Körner and Larcher, 1988; Barry, 1992).
