Phytosociology: A modern geobotanical method

Abstract

Vegetation Science is a scientific discipline devoted to the study of vegetation at all levels of complexity spanning populations, plant communities and biomes. It attempts to explain vegetation patterns and the processes governing vegetation assembly and dynamics in all temporal and spatial scales. Vegetation analysis serves to record anthropo-zoogenic effects and portrays similarly structured vegetation formations with characteristic vegetation complexes and plant communities. These plant communities consist of recognisable and reproducible associations of plant types which are subject to natural laws under the same ecological conditions. Wherever one finds similar habitat conditions in comparable bioregions or floristic zones on the planet, similar communities exist and can be typified. Such determinative plant community-habitat-type systems possess high bioindicator value for different biotic and abiotic habitat conditions. The floristic compositions and structure of plant communities and biotope-types can be categorised, and such vegetation units can be abstracted as elementary types, marked by their characteristic species combination under certain habitat-dependent conditions. Phytosociology provides the scientific background and method to address these questions. It was established by Josias Braun-Blanquet (Braun-Blanquet J. 1918. Eine pflanzengeographische Exkursion durch Unterengadin und in den schweizerischen Nationalpark. Beitr Geobot Landesaufnahme 4: 1–80.) and promoted for example in Germany by Reinhold Tüxen (Tüxen R. 1937. Die Pflanzengesellschaften Nord-Westdeutschlands. Mitt. Flor. Soz. Arbeitsgemein. Nieders. 3, Hannover, 170 p.). The Flora-Fauna-Habitat-Guideline (FFH-Natura 2000), enacted on 21 May 1992 established homogenous criteria for endangered biotypes throughout Europe, founded on a modern phytosociological basis. Phytosociological terminology also forms the basis of biotype-differentiation in the UNESCO Convention on Biodiversity (COP9). Vegetation science is a socially and politically critical discipline, serving to benefit and progress human society and sustainable usage of its natural resources.