The epiphytic lichen vegetation on the trunks of Pinus sylvestris and Picea abies was studied and analysed by canonical correspondence analysis in relation to a number of environmental variables. The distribution and abundance of epiphytic lichen species proved to be dependent on the age of the stand, showing divergent responses in relation to phorophyte species and environmental variables such as acidity of the bark and vertical location on the trunk. The importance of stand age in the pattern of community variation is concluded to be an outcome of interaction between changes in the structure of the tree canopy, microclimate and properties of the bark. The responses of single lichen species to changes in the environment seem to vary considerably, indicating differences in competitive ability and ecological strategy between the species.