Alpine Acid Grassland

On crystalline rock and other lime-deficient substrates crocked sedge (Carex curvula) often predominates. The olive-green leaves of this species give the sward a perpetual autumn look and it has very low grazing value. Other flowering plants are not particularly well represented but still add welcome colour to the sward with the yellows of Arnica montana, Leontodon helveticus, Potentilla aurea and Senecio incanus ssp. carniolicus, and the blues of Campanula barbata, Veronica bellidioides and species of Phyteuma. In other acidic areas, such as the slopes near Puschlav the alpine, endemic grass Festuca varia (Poaceae) becomes widespread. A common companion is Carex sempervirens. In the lower alpine and sub-alpine belts Nardus strictus (mat grass) often becomes the dominant grass of acidic areas.

Alpine and Subalpine Heaths

In the Alps these can be divided into at least three separate associations. In the true alpine zone only a few woody species are able to survive. One of the most important of these is the prostrate azalea Loiseleuria procumbens and a few dwarf willows. The herbaceous willow Salix herbacea may occur in protected snow coombs for example. Creeping azalea heaths are often exposed to strong winds and may not gain a covering of protective snow during the winter and so can experience temperatures down to -40°C. In slightly less exposed areas other dwarf shrubs such as Arctostaphylos uva-ursi and Vaccinium uliginosum may be present. At lower levels, in the subalpine zone, Empetrum hermaphroditum (mountain cranberry) and Vaccinium uliginosum (bog bilberry) can form distinct heaths, but these formations are often protected by a covering on snow in winter, and as a result can grow to their full stature during the growing season, but many stands are now heavily grazed. More conspicuous in the sub alpine zone are alpenrose (Rhododendron ferrugineum) heaths with their displays of bright red flowers.

Alpine Acidic Scree

Surprisingly acidic, silicate scree tends to be more favourable to plant growth than limestone scree since it usually supports quantities of sandy soil that has a better water holding capacity than the soils of limestone screes. The main plant formation of these acidic screes is characterized by the alpine endemic Androsace alpina (Primulaceae). Other dominants may include Geum reptans and Trisetum spicatum, while typical endemic taxa include Gentiana bavarica var. subacaulis (Gentianaceae) and Saxifraga sequieri (Saxifragaceae). On silicate screes poor in humus, Oxygria digyna together with Adenostyles tomentosa and the alpine endemic Cerastium pedunculatum (Caryophyllaceae) may become conspicuous.

Alpine and Subalpine Acidic Rock and Boulder Formations

On silicate rocks in the Alps Androsace vandellii often characterizes the chasmophytic flora together with species such as the endemic or near endemic Erigeron gaudinii (Asteraceae), Eritrichum nanum (Boraginaceae) and Minuartia cherlerioides (Caryophyllaceae). At lower altitudes Primula hirsutum can become one of the main silicate rock fissure species, while the endemic Phyteuma scheuchzeri (Campanulaceae) is likely to be one of its associates.

References

Ellenberg, H. 1988. Vegetation Ecology of Central Europe. Cambridge University Press.

Favarger, C. 1972. Endemism in the montane floras of Europe. In: Taxonomy, Phytogeography and Evolution. Ed. D. H. Valentine. Academic Press.

Jentsch, A. & Beyschlag, W. 2003. Vegetation ecology of dry acidic grasslands in the lowland areas of central Europe. Flora, 198: 3-25.

Ozenda, P. 1983. The vegetation of the Alps. Council of Europe, Strasbourg.

Peter, M., Gigon, A., Edwards, P. J. & L├╝scher, A. 2009. Changes over three decades in the floristic composition of nutrient-poor grasslands in the Swiss Alps. Biodiversity and Conservation, 18: 547-567.

Polunin, O. & Walters, M. 1985. A guide to the vegetation of Britain and Europe. Oxford University Press.

Tribsch, A. 2004. Areas of endemism of vascular plants in the Eastern Alps in relation to Pleistocene glaciation. Journal of Biogeography, 31: 747-760.