Geothermal energy and air pollution at Larderello (Tuscany, central Italy): biodiversity of epiphytic lichens as indicator

The results of a biomonitoring survey carried out in the geothermal area of Larderello (Tuscany, central Italy) using the biodiversity of epiphytic lichens as an indicator of air pollution are reported. A "lichen desert" was lacking, and stations classified as "altered" were found only in the surroundings of two old power plants that ceased production in 1992 and 1997, respectively, and installations for the extraction of boron salts. Areas of "semi-alteration" were found in surrounding areas of all other power plants. The overall pattern of increasing biodiversity with distance from geothermal power plants suggested that air pollution from geothermal installations, chiefly hydrogen sulfide, is the main cause of the observed impoverishment in lichen communities.