Assessing photosynthetic biomarkers in lichen transplants exposed under different light regimes

tThe present work is a methodological study testing alternative exposure conditions of lichen transplantsfor biomonitoring studies. We evaluated the effects of different light regime on the vitality of lichenby analysing the photosynthetic efficiency of transplanted thalli of the fruticose species Pseudeverniafurfuracea (L.) Zopf. var. furfuracea. In particular, we tested the hypothesis that shading lichen transplantsis necessary to ensure sufficient lichen vitality during the exposure time. Thalli of P. furfuracea wereexposed in a polluted area within the harbour of Genoa (N-Italy) for 4 weeks under two experimentalconditions: 5 thalli were covered with a shade cloth, whereas 5 thalli were kept in the light. We showedthat, under the same environmental conditions (i.e., climate and pollution regime), shading the thalliminimised the photoinhibition and prolonged the vitality of the lichen. Thus, we recommend shadinglichen transplants during biomonitoring surveys to better detect the effects of pollution on the lichens.