| Three sampling sites were analysed in each of the following tropical regions: 1) northwestern São Paulo State, representing a disturbed region; 2) Bonito, Mato Grosso do Sul State, representing a hard water region; and 3) Ubatuba, northern costal region of São Paulo State, a well preserved tropical rainforest region. The hard water region had the highest mean values for macroalgal species richness (6.3) and diversity index (H' = 0.62). Northwest and rainforest regions had the highest percent cover values (22.5% and 17.0%, respectively). All sites in the northwest region had one or two dominant species (percent cover significantly higher than the remaining species), characterizing the niche pre-emption distribution pattern. The same pattern was found in two... |
