Contributo alla conoscenza sintassonomica dei boschi del Tilio-Acerion Klika 1955 dell’Appennino centro-settentrionale (Italia centrale).

A phytosociological study of the Tilio-Acerion woodlands in the northern part of the central Apennine chain is presented. 71 unpublished relevés were analysed using the Twinspan software. Four groups are recognised: the first one is referred to the Ornithogalo sphaerocarpi-Aceretum pseudoplatani association in its typical form; the second is characterized by species linked with deep soils with a good presence of clay and has been referred to the new subassociation Ornithogalo sphaerocarpi-Aceretum pseudoplatani geranietosum nodosi; the third group is referred to the new association Glechomo hirsutae-Aceretum obtusati characterized by species linked with nitrophilous and saxicolous conditions of the microhabitat; the ultimate group is formed by little phytocoenoses isolated in a matrix formed by exstensive pastured areas and a syntaxonomic treatments is not proposed.