Lichens as Bioindicators of Air Quality in DistantAreas in Patagonia (Argentina)

摘要

This contribution is part of a more extensive assessment of the effects of air pollution inurban environments in Patagonia (Argentina) through its effects on the lichen flora.Different methodologies were applied. This paper presents calculations of the Index ofAtmospheric Purity (IAP) for urban contaminated (Bariloche city) and periurbanuncontaminated environments, calculated at sites for which data were available on theelemental composition of contaminating elements. The IAP results obtained were cor-related with the elemental composition of lichen thalli. Principal Component Analysisand Cluster Analysis were performed to determine data partitioning using Ward'smethod. The results yielded four clusters: three of them correspond to thalli and IAPvalues from urban areas, where the most important factors affecting the lichen florahave been identified as their proximity to medium to high traffic density or petrolstations. Thalli from periurban uncontaminated environments form an independentcluster, characterized by lower concentrations of contaminating elements and higherIAP values. The results obtained allow IAP to be related atmospheric conditions inthese human settlements and evaluation of the ecological effects of these settlements onthe natural environment by comparison with unaltered surrounding environments.