AQUATIC AND TERRESTRIAL VEGETATION OF THE PRESPA AREA

We studied the vegetation of the aquatic ecosystems of Lake Mikri Pres pa. The lacustrine vegetation comprises three distinct forms: floating plants, benthic hydrophytes and helophytes, which are described and c lassified from the phytosociological point of view, as follows: (a) th e vegetation of the floating plants belong to the Lemnetea class and i s represented by two plant communities; (b) the vegetation of the bent hic hydrophytes, belongs to the Potametea class consisting of two diff erent categories, namely the submersed formations and the emergent for mations of the hydrophytes. Various plant communities were recognised in this type of vegetation and three among them are considered as the most representative, (c) the vegetation of helophytes, the prevailing life form in this wetland, belongs to the Phragmitetea class and is re presented mainly by seven well organised plant communities. The respec tive vegetation of two of the five more important wetland sites is des cribed. The terrestrial vegetation is composed of forest and meadow ve getation. The forest vegetation of the National Park belongs to the cl ass Querco-Fagetea and shows the following zonation: (a) in the vicini ty of the lake, at the elevation of 860-1000 m, two associations have been found: the mixed deciduous and evergreen forests of Ostryo-Carpin ion orientalis and the evergreen forests of Ostryo-Carpinion adriaticu m; (b) the deciduous oak forests surround the previous zone at the alt itude of 900-1300 m with two principal associations, namely the Querce tum frainetto and the Quercetum petraeae; (c) in the upper forest laye r between 1200-1800 m asI, dominate beech forests of the association F agion moesiacum and the less extensive occurrence of the mixed beech-f ir stands (Ass. Abieti-Fagetum moesiacum). The zone above the tree lim it is distinguished by its subalpine character semi-shrub vegetation e xtending higher than the forest (1800-2000 m), whereas alpine meadows cover the vegetation at higher altitudes. On the plains and in the for est clearings exist herbaceous meadow formations of variable structure , in parallel with the vegetation of specific habitats, such as nitrop hilous and ammophilous plants.