The Association Erysimo - Trifolietum Micev. 1977 in Bulgaria and Some Remarks on its Mediterranean Character
We endeavor to enlarge the knowledge about Bulgarian vegetation diversity. Data on seminatural grasslands containing 344 relevés, collected in Southeast Bulgaria were analyzed by the combine method, using TWIN-SPAN and the Cocktail method. The Erysimo diffusii-Trifolietum angustifolii association and the alliance Trifolion cherleri were established for the first time in Bulgaria. So far the presence of this association was known for Macedonia. The aims of our study are to present more data about the Erysimo-Trifolietum in Bulgaria and to make some comments about its affiliation to Helianthemetea guttati. The association is characterized ecologically and floristically. Analysis of the floristic elements shows that the most numerous are sub-Mediterranean species. Analysis of the life forms shows that these communities are hemicryptophyte-therophytic. A review of syntaxonomical systems and association assignment to higher syntaxa were made. According to current European vege-tation surveys the association should be related to class Helianthemetea guttati. Our results reveal an intermediate character of the studied vegetation - closed dry grasslands, with distinct presence of Festuco-Brometea species with a high percent of therophytes and Mediterranean floristic elements related to Helianthemetea guttati as well.
The geographic position of Bulgaria results in a variety of climatic and biogeographic influences on the country’s vegetation. We aim to describe the plant diversity of dry grasslands distributed in the transitional belt between the south-eastern European and Mediterranean biogeographic regions in SE Bulgaria, and to reveal if there are any obvious differences in soil properties, presence of life forms and chorotypes between syntaxa. The data set consists of 349 releves of vascular plants and bryophytes sampled in different semi-natural herbaceous vegetation types. By applying TWINSPAN, we classified 176 releves of dry grasslands to eight associations and one unranked community. One association and two subassociations are described here for the first time. Data on soil depth, soil moisture, soil pH, humus and total N content, numbers of different life forms and chorotypes were analysed statistically. The dry grasslands in SE Bulgaria were classified into different vegetation classes sharing the same territory: their communities present similarities in species composition and they have similar ratios of hemicryptophytes/therophytes and Euro-Asiatic/Mediterranean species. Dry grassland vegetation occupies mostly shallow and dry soils that vary slightly in pH, humus content and soil moisture between associations.
This study deals with the diversity of forest vegetation in the Slivenska Mountain (Eastern Stara planina) and presents a contemporary classification scheme for the identified syntaxa. A total of 137 relevés were collected and analyzed using specialized software (JUICE 7.0 and PC-ORD Version 4). As a result, forest vegetation is classified into 10 associations, 3 subassociations, 4 variants and 5 communities They belong to 7 alliances, 5 orders and 3 classes: Carpino-Fagetea sylvaticae, Quercetea pubescentis and Alno glutinosae-Populetea albae. The recorded 18 distinguished vegetation groups show a relatively high diversity of forest plant communities of the study area.