A Harkány-Nagynyárádi-sík zárt lösztölgyesei (Pulmonario mollis-Quercetum roboris Kevey 2008)

Abstract

The study deal with the phytosociological charac-teristics of oak forests growing on the loess-covered hills on the Harkány-Nagynyárád plain, where the author found rep-resentative stands of a recently described community, the closed pedunculate oak forest on loess (Pulmonario mollis-Quercetum roboris). This community occupies xero-mesic habitats between the more xeric habitat of the open steppe woodland (Aceri tatarici-Quercetum roboris) and the mesic habitats of the closed oak-hornbeam forest (Corydali cavae-Carpinetum). In terms of its ecological role, this community is the ecological equivalent of the closed pedunculate oak forest on calcareous sand (Convallario-Quercetum roboris). In the closed pedunculate oak forest, character species of dry grasslands (Festuco-Brometea, Festucetalia valesia-cae, Festucion rupicolae, etc.) play a subordinate role as opposed to the open steppe woodland, in which these spe-cies are prevalent. Unlike the open steppe woodland, the community harbors a number of mesic species (Querco-Fagetea, Fagetalia, Carpinenion) in the understorey, owing to the xero-mesic character of its habitat. It is separated from the often adjoining stands of closed oak-hornbeam forest, which grows at the bottom of the valleys, by the oc-currence of species characteristic of dry oak woods (Quer-cetea pubescentis-petraeae, Quercetalia cerridis, Aceri tatarici-Quercion), and the absence of several mesic spe-cies (Querco-Fagetea, Fagetalia, Carpinenion) typical in the oak-hornbeam forest. This community is thus classified as a member of the Polygonato latifolio-Quercenion roboris Kevey 2008 suballiance.