A relatively quick and simple method is presented for monitoring changes in distribution and in site and substratum preferences of epiphytic macrolichens; the method also records the natural turnover of common species. Changes in the epiphytic lichen flora in southern Sweden were recorded at 64 sites in 1986 and again in 2003. In total 1990 observations of lichens were recorded on 15 tree species, mainly on trunks but also on branches up to 2 m above the ground. Almost all species showed a high turnover with regard to substratum, including very abundant species such as Hypogymnia physodes. Many of the species had changed substratum within their sites, possibly reflecting a general change in the ecological quality of sites. Canonical Correspondence Analysis was used to extract the variation in species composition over time, using 1685 records of 55 lichen species on 8 different substrata. Some species such as Hypogymnia tubulosa had increased in abundance whilst others such as Vulpicida pinastri had decreased.
