Temporal variation of air pollution in a geothermal area of central Italy: assessment by the biodiversity of epiphytic lichens

The results of a biomonitoring survey carried out in the geothermal area of Travale-Radicondoli (central Italy) are reported. The aim of the study was to evaluate the temporal variation of air pollution from 1992 to the present, based on the actual biodiversity of the epiphytic lichens compared with that of a previous study in the same area. Although instrumental measurements were not available, it was assumed that variations in the lichen biodiversity mostly reflected changes in the air pollution status. Furthermore, adopting a "before-after" strategy, the impact of a sansa oil extraction plant built in 1993 was also evaluated. The results showed that after 8 years, the geothermal area of Travale-Radicondoli is undergoing a gradual process of improvement, as clearly indicated by the colonization of some lichen species in areas previously affected by the "lichen desert". The surroundings of the geothermal power plants did not show evident changes from the previous study, as the biodiversity values remained low. The sansa oil extraction plant had a noticeable environmental impact that caused the air quality to worsen