The impact of traffic on the epiphytic lichen species composition

For the assessment of traffic-originated pollutants input into the environmentand their impact on biocenosis, the passive bioindication was used at eight selected road sections, where mapping of epiphytic lichen flora was implemented according to a German (VDI) method. The mapping of epiphytic lichens implies that lichens can be used in bioindication studies along roads; indeed, at locations with higher traffic density (average daily traffic > 20,000) fewer lichen species were identified in comparison with locations with lower traffic density. At road sections with very high traffic density only epiphytic lichen species most resistant to pollution were recorded, while less resistant but still highly tolerant to nitrogen pollution lichen species were recorded at road sections with moderate traffic density (average daily traffic around 10,000). At those road sections, the lichen species more sensitive to air pollution also begin to occur, which were not recorded at road sections with very high traffic density, not even 100 m away from the roadside.