Bengtsson, O./ H. Paltto 2013: Changes in the epiphytic flora over 17 years in Härryda, southwest Sweden. - Svensk Botanisk Tidskrift107(2): 100-105. [RLL List # 232 / Rec.# 34852] Abstract: We describe the results of a monitoring programme of the epiphytic moss and lichen flora at 20 sites in Härryda from 1992 to 2009. At each site two or three trees (in total 57 trees) were surveyed for mosses and lichens. Most trees were species with neutral bark: ash, Norway maple and elm. The average number of lichen species per tree did not change over time whereas the number of bryophytes increased by 20%. Several lichen species with a preference for acidic substrates declined. The reduction is significant for Hypogymrtiaphysodes, Platismatia glauca and Melanelixia glabratula. The reduction of sulphur pollution over recent decades is the most likely explanation. Lichens with Trentepholia algae increased. It has been suggested that these species are favoured by global warming. Species in the red data book were recorded from a limited number of trees and the situation appears to be stable.