Ranking of epiphytic lichen sensitivity to air pollution using survey data: A comparison of indicator scales

Epiphytic lichens were recorded on wayside trees in the Netherlands. Four s tatistical methods were used to detect the relationship between presence an d abundance of lichen species and measured atmospheric concentrations of SO 2, NO2 and NH3. The observed relationships were compared to published indic ator scales of lichen sensitivity to atmospheric pollution. For SO2, a good agreement was found between all scales and calculated sensitivities based on presence or absence of species. For NO2 and NH3 the correspondence was l ess obvious. The sensitivity to NH, was inversely related to Wirth's acidit y indicator scale. Species that react positively to NH, tend to be sensitiv e to SO2 and NO2. (C) 1999 The British Lichen Society.