Biomonitoring of geothermal air pollution by epiphytic lichens and forest trees in central Italy

Epiphyti¢ lichens and forest trees have been used as biomonitors of geothermal air pollution in the Travale-Radicondoliarea (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 colltaminationand boron as the main U'ace 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 specificdry weight were well correlatedwith the presence of the geothermalpower plants. High levels of sulphur were detected in leaf'tissues