INTERACTION BETWEEN SULFUR-DIOXIDE AND NITRATE IN SOME LICHENS

Lichen sensitivity to So2, NO3- and to the combination of both pollutants in three fruticose lichen species, Anaptychia ciliaris (L.) Korber, Evernia prunastri (L.) Ach. and Ramalina farinacea (L.) Ach., was studied by evaluating pigment status. A synergistic inhibitory effect of the combination SO2 + NO3- was evident. The role of NO3- as a nutrient and as a phytotoxic agent, as well as the differential sensitivity of the species to SO2 when applied alone, are discussed.