Fern and lycophyte communities at contrasting altitudes in Brazil’s subtropical Atlantic Rain Forest

Abstract

Ferns and lycophytes are a species-rich group in Brazil’s Atlantic Rain Forest, but studies on richness and diversity patterns on a regional scope are scarce. We investigated communities at different altitudinal belts in the Atlantic Rain Forest in southern Brazil, spanning from lowland and submontane to montane and upper montane forest formations. We tested the hypotheses that each forest formation differed in its fern and lycophyte community composition and that species richness peaked in montane forests. Species composition, from the ground level to the phorophyte canopy, was studied at five sites per belt (together 120 plots of 10 × 10 m). Species were according to substrate types (epiphytic, rupicolous and terrestrial species). Analyses were conducted for the entire species set, and for the epiphytic, terrestrial and rupicolous component separately. We found a total of 139 species of ferns and lycophytes, of which Polypodiaceae was the family with the highest species number. Overall composition differed among altitudes and for the three substrate types. Richness was highest in the montane and upper montane formations. The study indicated the presence both of species with high habitat specificity and of species with broad ecological amplitude along the gradient. Altogether, our study reduces the lack of information ferns and lycophytes communities at a regional scale and confirms the high diversity of this group for biodiversity in the Brazil’s Atlantic Forest.