Lichen communities as bioindicators of the Aburra Valley air quality

Lichens have been used as bioindicators of air quality. They are sensitive to changes in air composition at any given site affecting their abundance, biomass and vitality.This study evaluated lichen affectation as a consequence of air pollution. Two study areas within the Aburra Valley and the RedAire network were selected: Miguel Aguinaga (high pollution station) and the Medellin University (low pollution station). Four phorophytic tree species were chosen at each site Terminalia catappa Linneaus, Eritrina fusca Loureiro, Mangifera indica Linneaus y Fraxinus chinensis Roxb. The lichen cover by species, the vitality and the fructification were used to analyze the effect of air pollution. Finally, the lichen cover information was used to calculate the index of atmospheric purity (IAP) and the Q factor determination. Total qualitative and quantitative information obtained made evident that Canoparmelia sp. and Parmotrema austrosinensis (Zahlbr) Hale. lichen species are the most sensitive, and therefore appropriate to assess air quality. Additionally, the statistical analysis carried out using the relative abundances by phorophytic trees, showed that Fraxinus chinensis Roxb is the most appropriate tree species for bioindicator lichens studies into the Aburra valley.