The Alliances Arrhenatherion, Cynosurion and Trifolion Medii in Western Bulgaria - Environmental Gradients and Ecological Limitations

The vegetation of mesic grasslands distributed in the central part of Western Bulgaria is studied. A significant number of 533 relevés were made following the Braun-Blanquet approach. Classification and ordination of the vegetation was performed. The vegetation is classified up to alliance level. The result of the classification are four groups which correspond to the alliances Arrhenatherion elatioris, Cynosurion cristati and Trifolion medii. Within Cynosurion alliance two well distinct subgroups are observed, differing in moisture of the substrate - provisionally called "wet" and "dry" Cynosurion. Ellenberg Indicator Values are used for assessment of ecology of the habitats. The pasture/mowing management of the studied vegetation types is commented.