Ecological-vegetational and syntaxonomic characterisation of Quercus robur-dominated forests in Central Italy

Aims: Herein, the ecological, biogeographical, distributional, and syntaxonomic framework of Quercus roburdominated forest communities at the southern limit of the species distribution is outlined for the first time. Study area: The study was conducted in Central Italy. Methods: A total of 87 phytosociological relev & eacute;s, both published and unpublished, using the Braun-Blanquet approach were used. For literature data, phytosociological relev & eacute;s with a clearly dominant Quercus robur coverage >= 3 (Braun-Blanquet scale) and referring to syntaxa described at the association or aggregation level containing the Quercus robur epithet were selected. For each relev & eacute;, chronological spectra and mean indication values were calculated using Ellenberg indicator values (EIVs). The main vegetation groups were identified using cluster analysis and principal component analysis ordination. Each vegetation group was associated with a chorogical spectrum, average EIVs, and diagnostic species obtained from the indicator species analysis (ISA). Results: Six vegetation types, linked to four ecological and floristic contexts well defined by the chorological spectrum, EIVs, and ISAs, belonging to four alliances were identified: Carici remotae-Fraxinion oxycarpae and Lauro nobilis-Ulmion minoris of the class Alno glutinosae-Populetea albae, Carpinion orientalis and Physospermo verticillati-Quercion cerris of the class Querco roboris-Fagetea sylvaticae. Conclusions: The new association Carpino orientalis-Quercetum roboris of the alliance Carpinion orientalis on the pre-Apennine side of the Marche region was described. Additionally, the variability of the Fraxino oxycarpae-Quercetum roboris association was redefined with the proposal to elevate the subassociation sambucetosum nigrae to the rank of association Sambuco nigrae-Quercetum roboris which can be referred to the Lauro nobilis-Ulmion minoris alliance.