SYNTAXONOMY OF QUERCUS CERRIS AND OSTRYA CARPINIFOLIA WOODS IN THE NORTHERN APENNINES OF THE MARCHE REGION (ITALY). The AA. discuss the syntaxonomy of Quercus cerris and Ostrya carpinifolia woods in the northern Apennines of Marche region (Pesaro-Urbino province), with special reference to communities growing on flysch soils. According to cluster analysis by average linkage, the following types are recognized: a) Aceri (obtusati)-Quercetum cerris (Ubaldi 1979) em, colline-submontane association, including mixed woods with Quercus cerris, Ostrya carpinifolia, Acer obtusatum and Fraxinus ornus; b) Seslerio (italicae) Ostryetum (Ubaldi 1974) em., including Ostrya carpinifolia woods on little deep soils of marl-calcareous flysch; this type lies in the montane belt, in the Cephalanthero-Fagetum zone; c) Ostrya carpinifolia Fagus sylvatica-Calamagrostis varia community; mountain woods near to Cephalanthero-Fagetum sociology; d) Arisaro (proboscidei)-Carpinetum ass. nova, including Quercus cerris-Carpinus betulus-Fagus sylvatica woods, occurring in the Aceri (obtusati)-Quercetum cerris belt.
These types may be included in a Orno-Ostryon, floristically delimited by Lilium croceum, Laburnum anagyroides, Ostrya carpinifolia and Acer obtusatum. Compared to Orno-Ostryon of yugoslav Authors, and particularly to Ostryo-Carpinion orientalis, it is more mesophilous and near to Capinion betuli. According to our present knowledges, this Orno-Ostryon lies in the Central and Northern Apennines and in the Centrai Pre-Alps too. For this vegetation Ubaldi(1981) has suggested the name Laburno-Ostryon carpinifoliae.
