Vascular epiphytes on Pseudobombax (Malvaceae) in rocky outcrops (inselbergs) in Brazilian Atlantic Rainforest: basis for conservation of a threatened ecosystem

Abstract This study evaluated the richness of vascular epiphytes on Pseudobombax sp. nov. in three inselbergs in the Atlantic Forest Domain in state of Espírito Santo and evaluated the floristic similarity between the areas. We sampled 111 phorophytes in three regions in the southern of Espírito Santo state and identified 151 species, 77 genera and 21 families of vascular epiphytes, of which the families Orchidaceae and Bromeliaceae showed the highest richness. Non-parametric estimators (Chao 2, Jackknife 1) indicate that 90 and 95% of species richness of epiphytes was recorded. The most diversified ecological category was the characteristic holoepiphytes. The ratio of the number of epiphytes and number of phorophytes sampled in a montane inselberg, in this study, was greater than the richness of vascular epiphytes found in the rocky outcrops of quartzite, and, in general, different types of Atlantic Domain forests, but smaller in richness for some Dense Ombrophilous Forests of southern Brazil. The three inselberg areas had distinct floras. The high richness, the endemism found, and the number of endangered species of epiphytes demonstrate the important role of Pseudobombax sp. nov., because of its architecture and size, in the maintenance of biodiversity on the inselbergs in southeastern Brazil.