Mixed forests of Acer pseudoplatanus, Fraxinus excelsior and Ulmus glabra, developed on colluvial deep soils at the foot of very rainy slopes and on rarely inundated river sediments of the submontane to high montane levels of the northern pre-Alps and their piedmont, with Prunus avium, Prunus padus, Alnus incana, Alnus glutinosa, Fagus sylvatica, Carpinus betulus, Quercus robur, Corylus avellana, Mercurialis perennis, Aegopodium podagraria, Cirsium oleraceum, Deschampsia cespitosa, Filipendula ulmaria, Carex pendula, Equisetum telmateia, Matteuccia struthiopteris, Primula elatior, Brachypodium sylvaticum, Cardamine trifolia, Carex sylvatica, Paris quadrifolia, Stachys sylvatica.