Richness and composition of ferns and licophytes in a hectare of Mixed Humid Forest in Rio Grande do Sul, Brazil

Abstract

In Southern Brazil, the Mixed Humid Forest (MHF) presents a large richness of ferns and licophytes. A floristic survey of the fern and licophyte species occurring in one hectare of MHF was accomplished at the “Parque Natural Municipal da Ronda” (PNMR), in the municipality of São Francisco de Paula (29º26’50.5”S and 50º32´54.2”W; mean altitude 870m), Rio Grande do Sul (RS), emphasizing the life and growth forms, as well as the preferential substrate of the plants. A total of 42 species was recorded, belonging to 28 genera and 15 families, 40 of them being ferns. The hemicryptophyte life form presented the highest specific richness (n=20), being 12 of the species of reptant growth and eight of rosulate growth. The majority of species was terrestrial (n=23). The specific richness found in just one hectare of forest corresponds to 12% of the total fern and licophyte species listed for RS and shows the importance of the Park for the conservation of biodiversity in MHF fragments.