Scree forests (Mercuriali-Tilietum) of the Börzsöny Mountains, Hungary

Scree forest communities Mercuriali-Tilietum Zólyomi et Jakucs 1958 of Börzsöny Mts were not processed until the present. These lime-dominated forests develop on andesite base-rock, mainly on periglacial scree surfaces. Using the Braun-Blanquet-Soó method 15 sampling spots were studied and analysed based on floristical composition, cenological aspects and habitat characteristics. The stand's species stock consists of tree species like Acer platanoides, Carpinus betulus, Fraxinus excelsior, Tilia platyphyllos, shrubs like Cornus mas, Corylus avellana, Euonymus verrucosus, Ribes uva-crispa and herbs like Cystopteris fragilis, Dryopteris filix-mas, Galeobdolon luteum, Galium schultesii, G. odoratum, Hedera helix, Melica uniflora, Mercurialis perennis, Mycelis muralis, Poa nemoralis, Waldsteinia geoides. Rare Tilio-Acerion species are Adoxa moschatellina, Gagea minima, Geranium lucidum. Cenological categories, life forms, geoelement distribution, and Borhidi's Social Behaviour Types were studied on the basis of the synthetic table. Relative ecological T, W, R values according to Zólyomi, and Borhidi's continentality were also evaluated. Results were compared to Parietario-Aceretum (Horánszky 1964) Soó 1971 community belonging to alliance Tilio platyphylli-Acerion pseudoplatani. This andesitic gorge forest community where highly dominant species are Acer pseudoplatanus, Fagus sylvatica, Fraxinus excelsior is a closely related to the scree forests