Biomonitoring of geothermal air pollution by epiphytic lichens and forest trees

Epiphytic lichens and forest trees have been used as biomonitors of geothermal air pollution in the Travale-Radicondoli area (central Italy). The diversity of the lichen flora and the crown status of Quercus cerris were taken as active indicators of air quality, and both lichens Parmelia caperata and tree leaves were analyzed for their elemental content. The lichen survey pointed out a belt of about 500 m around the power plants as the area of highest contamination and boron as the main trace pollutant. As far as forest trees were concerned, crown thinness was affected mostly by the nature of the geological substrate, while reduction in leaf area and increase in specific dry weight were well correlated with the presence of the geothermal power plants. High levels of sulphur were detected in leaf tissues.