Habitates and Levels of Vegetation

In nature, individual plants form populations; different species form plant communities whose members share soil and climatic requirements. If these conditions change the plant communities change as well. Chemistry and food resources provided by the ground will vary depending on the underlying rock. Acid soil grows on silicate rock (frequently called primary rock) as it derives from magma from the earth’s core. Alkali soils are found on lime rock created from the marine sediments of skeletons of corals and chalk algae.
Most alpine plants have adapted their metabolism to one or other type of soil; some of them tolerate both kinds of soil.


We thus speak of silicate and lime vegetation.
With increasing sea level, the climate becomes rougher; the atmosphere becomes colder; wind frost and duration of snow cover increases.
The time available to plants for useful (re)production becomes increasingly shorter. Certain plant societies reach their highest survival level at different sea levels and we can compare these levels of vegetation to the storeys of a house: in the drier and warmer Inner Alps the deciduous woods of the warm valley floors to the higher perennial wood levels of the Fir or the Norway Spruce (Pinus sylvestris or Picea abies), and finally by the Larch and the Arolla Pine (Larix decidua and Pinus cembra), forming the border to tree growth.

At the less arid and cooler foot of the Alps the Beech (Fagus sylvatica) and Dwarf Mountain Pine (Pinus mugo) grow tallest. All these plant communities have accommodated themselves to the given soil and climatic conditions, and we therefore speak of climax vegetation. The levels of vegetation are influenced by the macro-climate, the individual plant communities within the alpine level on the location profile.

Above the tree line the kingdom of the dwarf shrub heath of Alpenrose and berry bushes begins and above, that of the alpine meadows, which above 3000 metres sea level shift to favourable south-facing locations and then peter out. On alkali or neutral soils on lime or dolomite, such as found on the Kitzbuehel Horn, we find the Wimper Alpenrose (Rhododendron hirsutum), and on acid grounds on silicate rock the rust red Alpenrose (Rhododendron ferrugineum). The alpine meadows differ more widely: on deep lime rich soil lush flowering Blue Sesleria-Evergreen Sedge slope (Seslerio-caricetum sempervirentis). Then further up, on shallow rock ridges the Cushion Sedge pioneer sward (Caricetum firmae) supersede. Even on lime rock the ground can turn acid due to the accumulation of humus soil.
Mat grass meadows (Nardetum) then form the widespread pasture meadows of the mountain pastures. In the silicate mountains the brush meadows change into Crooked Sedge sward (Caricetum curvulae), which in some areas, with exposure to the south, can grow above 3000 metres sea level. Wind threatened plants not only live by drawing water, which leads to them drying out rather than freezing (frost parching), but in the placement of snow also. This can be observed quite clearly when investigating thaw patterns. The terrain profile generally determines the microclimate of the plant location and thus the distribution of the vegetation: on snow free, windblown ridges the only a few centimetres tall trellises of Creeping Azalea (Loiseleuria procumbens), or further up the steppe, meadows of Naked Rush (Elyna myosuroides) survive.
In hollows covered with snow for long periods of time, i.e. up to more than 6 months snow terrain, only temperate specialists like Dwarf Willow (Salix herbacea), Retuse Leaved Willow (Salix retusa), Dwarf Cudweed (Gnaphalium supinum), Sibaldia (Sibbaldia procumbes) or lichens (e.g. Solorina crocea) can survive.

Habitates and Levels of Vegetation

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