Richness and distribution of aquatic pteridophytes in wetlands of the State of Rio Grande do Sul (Brazil)

ROLON, A.S. & MALTCHIK¹, L.

¹ Ecology and Conservation & Aquatic Ecosystems, Universidade do Vale do Rio dos Sinos, UNISINOS. São Leopoldo, Rio Grande do Sul, Brazil. 93022-000 maltchik@bios.unisinos.br

ABSTRACT: Wetlands are among the most important ecosystems on Earth. These systems must be considered as biological reserves because of the extensive food chain and rich biodiversity they support. In this sense, wetlands are important sites for conservation. Studies of biodiversity and distribution of aquatic pteridophytes are scarce in the world. The goal of this study was to analyze the richness and distribution of aquatic pteridophytes in wetlands in the State of Rio Grande do Sul using the Rapid Assessment Programme for Biodiversity as tool. Six pteridophyte species belonging to 4 families were observed: Azolla filiculoides Lam., Equisetum giganteum L., Marsilea ancylopoda A. Braun, Regnellidium diphyllum Lindm., Salvinia herzogii De la Sota and Salvinia minima Bak.. The pteridophyte richness varied over the Rio Grande do Sul and was not related to altitude (R²= 0.004; P= 0.698) and wetland area (R²= 0.004; P= 0.699). The highest richness was found on the Coastal Plain (6 species), and most of the analyzed wetlands (68.3%) presented only one pteridophyte species.

Key-words: aquatic macrophytes, aquatic ferns, biodiversity, conservation, Aqua-rap.