Floristics and ecological aspects of lycophytes and ferns from the central coastal plain of Rio Grande do Sul state, Brazil

Abstract

We performed a floristic survey and an ecological characterization of the lycophytes and ferns from the municipalities of Cidreira, Balneário Pinhal and Palmares do Sul, midcoast of Rio Grande do Sul state, Brazil. The following aspects were assessed for the species: preferential substrate, life-forms, and occurrence in aquatic formations, wetlands, grasslands, ruderal formations, and swamp and dune forests. We found three lycophytes and 62 ferns. The Polypodiaceae had the highest species richness (15 ssp.), followed by the Pteridaceae (9 ssp.) and the Blechnaceae (9 ssp.). The environments with the highest species richness were ruderal and forest formations. The preferred substrate was terrestrial and the predominant life-forms were rosette and creeping hemicryptophytes. The results suggest a high species diversity in this portion of Rio Grande do Sul coast, yet lower than in other forest formations such as the Araucaria Forest or Dense Ombrophilous Forest. The high level of environmental disturbance and the degree of threat to species could be evidenced by the record of four endangered species in a regional scale.