Lichens as Bioindicators of Air Quality in Distant Areas in Patagonia (Argentina)
SUSANA CALVELO, NORA BACCALÁ, AND SANDRA LIBERATORE
Centro Regional Universitario Bariloche, Universidad Nacional del Comahue, Bariloche, Argentina
This contribution is part of a more extensive assessment of the effects of air pollution in urban environments in Patagonia (Argentina) through its effects on the lichen flora. Different methodologies were applied. This paper presents calculations of the Index of Atmospheric Purity (IAP) for urban contaminated (Bariloche city) and periurban uncontaminated environments, calculated at sites for which data were available on the elemental composition of contaminating elements. The IAP results obtained were correlated with the elemental composition of lichen thalli. Principal Component Analysis and Cluster Analysis were performed to determine data partitioning using Ward’s method. The results yielded four clusters: three of them correspond to thalli and IAP values from urban areas, where the most important factors affecting the lichen flora have been identified as their proximity to medium to high traffic density or petrol stations. Thalli from periurban uncontaminated environments form an independent cluster, characterized by lower concentrations of contaminating elements and higher IAP values. The results obtained allow IAP to be related to atmospheric conditions in these human settlements and evaluation of the ecological effects of these settlements on the natural environment by comparison with unaltered surrounding environments.
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