Ocorrência e cobertura de samambaias aquáticas e suas relações com os fatores abióticos

Abstract

When in overcrowding, the ferns can cause numerous ecological and economic problems, requiring the ecological knowledge of the species for making population control measures. In this context, the objective is to establish which and how abiotic variables influence the coverage and occurrence of aquatic ferns. The study was conducted in the state of Paraiba in 20 reservoirs located in three basins and two sub-basin. In each tank worked on a part-seven transects to collect biotic and abiotic data. GLM and CCA were performed to correlate the ferns with the variables. seven species of ferns found. Salvinia auriculata Aubl. and Ceratopteris thalictroides (L.) Brongn. They were related to environments with high concentrations of nitrate and ammonia. Azolla filiculoides was related to low pH, nitrate, ammonia and dissolved oxygen and Marsilea sp. at high pH values. The variables selected in GLM models showed greater similarity between the species of ferns with the same way of life. It is concluded that the coverage of the aquatic ferns and influenced by different environmental variables, and these variables are more similar to explain the occurrence of species with the same way of life.