Sulla presenza di boschi dell’alleanza Tilio-Acerion nella Riserva Naturale Integrale di Sasso Fratino e nella Riserva Naturale Biogenetica di Badia Prataglia-Lama (Parco Nazionale delle Foreste Casentinesi, Emilia-Romagna).

The forest vegetation of the Integral Nature Reserve “Sasso Fratino” and the Biogenetic Nature Reserve “Lama-Badia Prataglia” (eastern side of the National Park “Foreste Casentinesi”) was investigated using a phytosociological approach based on twenty sample plots carried out in the field. Plant communities floristically and physiognomically corresponding to the alliance Tilio-Acerion thanks to the abundance of “noble broadleaf” trees (genera Acer, Fraxinus, Tilia and Ulmus), were identified. Two ecologically different variants were found to occur, a more mesophilous and a more thermophilous one, both, however, belonging to the association Ornithogalo sphaerocarpi-Aceretum pseudoplatani subass. geranietosum nodosi; the two types were connected by transitional aspects. Some structural aspects of these forest communities werealso investigated, in particular stratification and basimetric area of the dominant broadleaf species. No relationship between the latter and the floristic richness in the sample plots was found. Finally, the number of species tended to decrease with increasing altitude of the plots, in a weakly but statistically significant way.