Biodiversity of the orophilous communities of Pino-Juniperetea class in the Central and Eastern Mediterranean area.

The authors examine the orophilous communities, occuring in the Central and Eastern Mediterranean area, characterized by the dominance of trees and shrubs belonging to the genera Juniperus, Abies and Pinus. These communities are localized in the supra- and oromediterranean belt and show a relict role. From the structural point of view, this kind of vegetation is usually bistratified, with a low dense shrubby layer and spaced tree layer; sometime the latter one is absent. This vegetation is floristically poor and characterized by prevalence of Coniferous, such as Juniperus sabina, J. foetidissima, J. excelsa, J. oxycedrus. J. hemisphaerica, J. communis, J. nana, Abies nebrodensis, A. alba, A. borisii regis, A. cicilica, and various taxa belonging to the cycle of Pinus sylvestris and Pinus nigra. Numerous shrubs of the genera Rosa, Daphne, Berberis, Prunus, Crataegus, Sorbus, Acer, etc. are here well-represented too. On the basis of personal unpubblished and literature data, a comparison among the various communities occuring in the Central and Eastern Mediterranean has pointed up that there is a remarkable flostical and structural homogeneity together with a series of geographical vicariants. From the phytosociological point of view, this justifies the arrangement of the aforsaid communities in one class only, Pino-Juniperetea, which is represented, in the examined area, by the order Juniperetalia hemisphaericae. This sintaxon comprises several alleances and suballeances which bear witness to a certain geographical isolation regarding some well-defined phytogeographical districts.