Beta diversity predictors of the phytoplankton community in a tropical floodplain

Our study aimed to evaluate how the physical and chemical characteristics of water, species dispersal, and land use affect the spatial beta diversity of phytoplankton (species composition and Morphology-Based Functional Groups—MBFG) in 50 lakes connected to the Araguaia River over a distance of 600 km. We considered beta diversity as the total variation of the Sorensen matrix and separated from beta diversity the turnover and nestedness compartments. We then performed a Partial Redundancy Analysis with all predictors and total beta diversity, turnover, and nestedness. We found the predominance of the turnover component for taxonomic data; conversely, we found the predominance of nestedness for functional groups. All predictors were influential for beta diversity and turnover in evaluating taxonomic data, while no predictor explained the nestedness component. Conversely, the total beta diversity of functional groups was influenced by the physical and chemical characteristics of water and land use, turnover only by dispersion, and nestedness by all factors except land use. This study demonstrated the importance of different predictors in phytoplankton beta diversity in the Araguaia River, highlighting the predominance of species turnover in community structure. Additionally, it reveals the presence of functional redundancy among species, indicating a complex interaction between environmental factors and biological diversity in the aquatic ecosystems of the region.