M. Waber et al., STANDARDIZED LICHEN EXPOSURE - CRITICAL-E VALUATION OF THE APPLICATION FOR BIOINDICATION OF IMMISSION EFFECTS, Gefahrstoffe, Reinhaltung der Luft, 57(7-8), 1997, pp. 337-338
In areas without natural lichen populations because of high levels of
air pollution the pollution effects can only be monitored by the activ
e method of ''standardized lichen exposure'' according to guideline VD
I 3799 part 2 [2]. Connected with a not immission caused total loss of
exposed lichens in the investigation area of Munich in 1992/1993 the
reliability and application perspectives of this method are critically
discussed. Repeatedly acclimatization stress or deep freezing before
exposition had been assumed to be the reason for a failure of this act
ive method. Future alternative application of the passive method of ''
lichen mapping'' should be considered where natural lichen populations
still exist - under the aspect of nature protection as well.