Effects of the urban environmental conditions on the physiology of lichen and moss

The lichen Evernia prunastri (L.) Ach. and the moss Ptilium crista-castrensis (Hedw.) DeNot were exposed in three different urban sites along with the different pollution loads in order to evaluate the environmental quality. Physiological changes after the exposition were assessed by evaluating the content of photosynthetic pigments, chlorophyll fluorescence, membrane lipid peroxidation and integrity of cell membranes. The differences in response of fluorescence, chlorophylls contents and injuries of cell membranes were observed between the two species and between the sites. E. prunastri showed a great capacity to sustain the photosynthesis processes in the urban environment, while this capacity was very low in the transplanted moss P. crista-castrensis. The levels of malondialdehyde (MDA) indicated a significantly higher oxidative stress in the transplants at urban and residential sites. The integrity of cell membranes in moss samples was also more damaged than in lichen.