The next study which using epiphytic lichens as indicators of environmental quality was from Munzi et al. (2007). The authors studied in Rome and used the applied Lichen Diversity (LD) method. The epiphytic lichen flora of Rome was composed mostly of species adapted to an anthropogenic environment, characterized by the complex interactions of contrasting biological and ecological variables. Significant changes in the lichen flora have been noted over the past 20 years, with the lowest diversity now being found in the urban centre and in the eastern and southern sectors, while the ‘‘lichen desert’’ area has decreased in parallel with decreasing concentrations of CO, NOx and SO2.