Interaction of sea salt and atmospheric pollution alters the OJIP fluorescence transient in the lichen Pseudevernia furfuracea (L.) Zopf

This study investigated the effects of the interaction of sea salt and atmospheric pollution on the photosynthetic system of the lichen Pseudevernia furfuracea (L.) Zopf. v. furfuracea. Thalli of P. furfuracea were transplanted from remote area to different sites subjected to contrasting levels of atmospheric pollution and distance from the coast. Lichen chlorophyll a fluorescence was analysed weekly for one month by means of Handy PEA fluorometer. The effects of sea salt and atmospheric pollution were assessed by OJIP fluorescence transient and its derived fluorescence parameters. We showed that the response of the lichen to the single considered stressing factors was different and it could be detected in terms of variation of the electron flow at different steps of the OJIP fluorescence transient. Our data confirmed that the derived JIP-test parameters are good biomarkers to analyse different conditions of stress in lichens. In particular, we demonstrated that P. furfuracea is more sensitive to atmospheric pollution than to the proximity to the sea and to the interaction of these two factors.