On the Occurence in Romania of Potentillo albae-Quercetum petraeae Libbert 1933 Association

The paper presents a plant community of dry-mesic oak forests that is new to Romania, Potentillo albae-Quercetum petraeae Libbert 1933. This association belongs to Quercion petraeae alliance and its range extends over the subcontinental area of Central Europe. A multivariate analysis (cluster analysis, non-metric multidimensional scaling ordination) of a large phytosociological database was used to identify diagnostic species, interspecific associations and the gradient of species composition. Based on species composition and site parameters, a group of relevees in oak forests that correspond to the diagnosis of Potentillo-Quercetum was identified. The Romanian relevees corresponding to this association were previously assigned, pro parte, to Carici montanae-Quercetum Gergely 1962 and Quercetum robori-petraeae Borza 1959. The relations with these and other potentially related two associations, Genisto tinctoriae-Quercetum petraeae Klika 1932 and Quercetum petraeae-cerris So� 1963, are discussed. The vegetation and site conditions of the Potentillo albae-Quercetum association in Romania are illustrated in a phytosociological table with 25 relevees and a distribution map is provided