Aspects of the postglacial history of lichen biota of forests in Central Europe, with special emphasis on montane beech forests (Fagetalia). – Based on recent observations, an attempt is made to reconstruct changes in lichen synusia of forests during the late Pleistocene and Holocene. The reflections are based largely on the premise that most epiphytes are adapted to certain pH-conditions and structural-anatomical bark features. These factors limit the potential spectrum of lichen species capable of establishing on the tree species mixtures dominating at any given period of time. Furthermore questions concerning speed of migration and origin of the forest lichens are discussed for the communities of the phytosociological order Fagetalia