The lichen flora of roadside trees in the Elbe Sandstones region (was observed using a modification of the LDV method, i. e. The European guideline for mapping lichen diversity as an indicator of environmental stress.
Due to the strong pollution of northern Bohemia, including study area, caused by heavy industry, especially carbon power plants and intensive mining (annual average concentration of SO2 was 20–30 μg/m3 in 1996), epiphytic lichen flora was strongly damaged. However, recolonisation of juvenile thalli of some more sensitive species (Usnea spp.) was recently observed on some trees.
Lichens were observed namely on Common Ash (Fraxinus excelsior). In total, 49 lichen taxa were found.
Measurement obtained by LDV method ranged from 3 to 64 for single trees, which indicates relatively poor development of the epiphytic lichen flora. Statistical analyses confirmed the negative influence of traffic and local pollution sources on epiphytic lichens.