Comunidade de liquens corticícolas em um gradiente de urbanização na Bacia Hidrográfica do Rio dos Sinos, no sul do Brasil

Lichens are known worldwide as indicators of environmental quality because they are sensitive to environmental changes, specially the ones with anthropogenic origin. In this study, we analyzed species composition, richness and coverage of corticolous lichen communities in nine municipalities with different urbanization levels, and evaluated their similarities considering lichen species composition. The studied sites were distributed in rural, rural/urban and urban/industrial matrices. Ten phorophytes were sampled in each area using the rubber band method. A total of 215 lichen species were identified, of which nine species are new records: four are being cited for Brazil for the first time, and five for Rio Grande do Sul. As urbanization increased, a simplification of the lichen community structure was observed, as well as a decrease in species richness and changes on species composition. Besides, in the urban/industrial matrix, few species had high coverage percentage and together added great importance to the community. We found higher homogeneity on species composition in closer areas and in the ones that were inserted in the urban/industrial matrix. This study showed that urban tree vegetation is an important factor for lichen species establishment along an urbanization gradient.