Plant societies and vegetation structure in the southern Gesäuse Mountains (Northern Limestone Alps, Styria)

The southern Gesäuse Mountains include the Admont Reichenstein Group and the Hochtorgruppe. The natural structure of the study area, its geology, climate, soils, flora.Vegetation history as well as natural and biotope conservation aspects are discussed in the introductory chapters of the thesis. The subalpine and alpine vegetation was studied in both massifs using plant sociological images according to BRAUN-BLANQUET (1964). Of the reception areas, one part was selected according to optical, floristic and structural criteria (approximately 500), another part (80) on the deep spiked soils due to a grid process. All recordings are recorded in Tables I to 33. The recordings were numerically classified; some of the resulting groups had to be reworked. Most groups correspond to one in MUCINA & al. (1993 a, b) and Grabherr & MUCINA (1993) plant societies (Associations). They belong to the following classes: Asplenieteatrichomanis.Thlaspietea rotundifolii, Montio-Cardaminetea, Scheuchzerio-Caricetea fuscae, Seslerietea albicantis, Carici rupestris-Kobresietea bellardii, Caricetea curvulae, Mulgedio-Aconitetea, Molinio-Arrhenatheretea, Erico-Pinetea. Some groups could not be assigned to a described plant society (association). Their probable syntaxonomic position is discussed. There is a strong floristic difference between the Seslerio-Caricetum sempervirentis and the Helictotrichon parlatorei-Carex sempervirens society. Their possible status as an assozition requires further comparative studies. The societies found on the spiked soils are discussed again for methodological reasons in a separate chapter, together with the smallest populations and clonal formations of otherwise rare species in the Northern Limestone Alps. The Agrostis rupestris Society and the Salix retusa-Oreochloa disticha-Gesellschaft may be relict floor companies. One of the latter similar Oreochloa disticha lawn was described by Pachernegg (1972) from the high swabbed of similar, relictic soils. Vegetation profiles have been made by some important societies. The structure and texture as well as the floristic similarities of the alpine cleft, rock grass and lawn societies are discussed on the basis of these profiles and a correspondence analysis. In this context, the alternative approaches of Wenninger (1951) to the Zurich-Montpellier School for the systematics of alpine lawns and rock fissure societies are discussed.