Afloramento de calcário como condicionante florístico estrutural de floresta estacional decidual

Abstract

The aim of this study was to describe the structure and floristic composition ofdifferent environments in a deciduous forest on a limestone outcrop in the municipality of Juvenília. We sampled five plots in each environment, totalling 25 plots, in which we recorded and measured all individuals with circumference at 1.30 m equalling or exceeding 10 cm. To assess floristic differences among the sampled environments, we applied non-metric multidimensional scaling (NMDS), beta diversity measures, rarefaction species curves, Shannon diversity index and Pielou’s evenness. We examined community structure through phytosociological parameters, dominance patterns (accumulated importance value, or IV), canonical correspondence analysis (CCA) and indicator species analysis. Through the NMDS, an ordination analysis, we verified that the environments differ significantly from each other, revealing distinct floristic compositions and high species substitution, which reflected directly on species richness and diversity patterns. Concerning community structure, we observed that the limestone outcrop also conditioned structural differences, altering the set of most important species (based on IV) and dominance patterns among the environments. On the other hand, the CCA showed that plots from the APR and AFSIA environments, despite having high fertility soils, were positively correlated with low aluminum acidity. Furthermore, the indicator species analysis showed that each environment has its particular set of species, corroborating the dissimilarities and high heterogeneity driven by the limestone outcrop.