Classification of continental halophytic grassland vegetation of Southeastern Europe

Aims: A syntaxonomic revision of saline grassland vegetation according to floristic, ecological and biogeographical characteristics. Study area: Southeastern Europe with special emphasis to the Southeastern Balkan. Methods: The set of 2,362 releves from published and unpublished sources originally classified into the classes Thero-Salicornietea, Festuco-Puccinellietea and Molinio-Arrhenatheretea was analysed. Cluster analysis and ordination of the dataset were performed to assess particular vegetation patterns. Diagnostic species of each cluster were determined using the phi-coefficient as a fidelity measure. Results: The analysed dataset could be arranged into four main groups reflecting soil salinity as a key factor for the differentiation of halophytic vegetation. The first group comprised communities of extremely saline and wet soils (Thero-Salicornietea), the second group included highly saline Pannonian grasslands (Puccinellietalia), whereas the third group was rather heterogeneous, grouping different types of saline and alkaline vegetation, mostly on solonetz soil, including vegetation developed on wet saline places, steppe grasslands (Artemisio-Festucetalia) and halophytic vegetation from southern Serbia and R. Macedonia (Puccinellion convolutae). The fourth group comprised sub-Mediterranean grasslands from Molinio-Arrhenatheretea class occurring in habitats of a low salinity level. Conclusions: Variation in different types of halophytic vegetation corresponds to the salinity and moisture gradients. This is an additional attempt of large-scale analysis of the halophytic vegetation focusing on the Southeastern Europe and Balkan in particular. The occurrence of the alliance Puccinelion convolutae was confirmed within saline habitats in southern Serbia. There is an urgent need for conservation of the studied halophytic flora and vegetation