A FLORISTIC SURVEY OF FERNS AND LYCOPHYTES ASSOCIATED WITH SEMI-DECIDUOUS FOREST REMNANTS IN SOUTHERN BRAZIL

Abstract

The richness of ferns and lycophytes associated with the semi-deciduous forests of southern Brazil remains poorly known. Addressing this situation, the richness of lycophytes and ferns in 11 semi-deciduous forest remnants, located in the northwestern region of Rio Grande do Sul State, Brazil, is presented. In total, four species of lycophytes (two families and two genera) and 88 species of ferns (15 families and 44 genera) were recorded. The most diverse families were Pteridaceae and Polypodiaceae, with 18 and 17 species respectively; Asplenium (10 spp.) was the most diverse genus. Among the recorded species, only Dicksonia sellowiana is cited in the Brazilian List of Threatened Plant Species. Most of the surveyed species have a broad distribution, occurring in South America (44.6%) and Tropical America (32.6%). The surveyed remnants showed intermediate species richness in relation to other areas previously studied in the state of Rio Grande do Sul, except for Parque Estadual do Turvo, where 81 species were recorded. The floristic similarity analysis shows that the Parque Estadual do Turvo is the most dissimilar area, presenting a high number (28) of exclusive species. The observed high value of the cophenetic correlation coefficient (0.968), indicate a small distortion between the similarity matrix and multidimensional space shown in the dendrogram. The present study constitutes an important contribution to the knowledge of the richness of ferns and lycophytes occurring in semi-deciduous forests in southern Brazil.