Physiological response of the epiphytic lichen Evernia prunastri (L.) Ach. to ecologically relevant nitrogen concentrations

► The lichen Evernia prunastri responds gradually to increasing N concentrations. ► Physiological effects happen increasing N concentration or number of treatments. ► The index of photosynthetic performance (PIABS) was the most sensitive parameter. ► This lichen species can be used as biomonitor of early N pollution effects.