Lichen community diversity on a remnant forest in south of Chaco region (Cordoba, Argentina)

The lichen community diversity in patches of Chaco forest -NE of Cordoba Province, Argentina was analyzed. Fifteen forest patches embedded in farmland areas were sampled. Size of the patch and exposure to the crops were registered. In each patch, ten trees (sample units) with epiphytic lichens were sampled. The cover for epiphytic lichen species and the number of species present were recorded. Shannon-Wiener diversity index was calculated for each patch and multivariate analyses (DCA and Indicator Species Analyses) were applied in order to study the composition of the community. The sample patches in the DCA were associated with patch exposition. Four quantitative variables (patch size, relative cover of Physciaceae, Parmeliaceae and Collemataceae; the most representative families) were related with the first two axes of DCA using correlations coefficients. Twenty one species in patches were identified. A multivariate analysis of sample units showed preferences of some species to exposure of patches to the crops. The data indicated that there would be a degradation marked by the impact of the edges on the remaining forests. There is a trend towards more homogeneous communities, formed by species resistant to these boundary conditions and possessing high coverage.