de Souza D. A. auteur aut IRD Kraus C. N. auteur aut IRD Burliga A. L. auteur aut IRD de Melo S. auteur aut IRD Couceiro S. auteur aut IRD Dias-Silva K. auteur aut IRD Simoes N. R. auteur aut IRD Braga T. auteur aut IRD Bonnet Marie-Paule auteur aut IRD Marques D. D. auteur aut IRD text journalArticle eng text/pdf born digital access The Amazon floodplains are complex systems influenced by the annual hydrological regime with an effect on the structuring of physical, chemical and biological processes. Thus, we evaluated the relationship of environmental factors with the composition and variation of functional groups based on morphology (MBFG) during the hydrological year in an Amazonian floodplain lake, with monthly sampling (2013 to 2014). We used analysis of variance (ANOVA) and Kruskal-Wallis to show differences in physicochemical variables between hydroperiods. We performed permutation analysis of variance (PERMANOVA) to assess the dissimilarity of morphofunctional groups between hydroperiods and also of environmental data between the months of the study and RDA redundancy analysis to assess the relationship between MBFGs and environmental data. It was registered 101 taxa distributed in eight taxonomic categories and was grouped into 5 MBFGs (III, IV, V, VI and VII), with Chlorophyceae (31 taxa) and Cyanobacteria (27 taxas) with the higher number of taxa. Furthermore, there was a dominance of Cyanobacteria in the total biovolume, which form blooms (MBFGs III and VII) during the periods of falling and low water in lake, influenced mainly by the reduction in the availability of light and an increase in temperature. In another scenario, the dominance of MBFGs V and VI occurred during periods of rising and high water with association with carbon compounds, rainfall, SRP and NO2. Thus, our results demonstrate that the availability of light, the concentration of nutrients and temperature were the most important variables for the morphofunctional structuring of phytoplankton in aquatic system. specialized Biovolume Environmental factors Aquatic system BRESIL AMAZONE BASSIN ZONE TROPICALE ZONE HUMIDE GRANDE DO CURUAI LAC 036 062 034 [Early access] [12 p.] 2022 1439-8621 https://www.documentation.ird.fr/hor/fdi:010083939 10.1007/s10201-021-00685-9 1439-8621 [F B010083939] https://www.documentation.ird.fr/hor/fdi:010083939 https://www.documentation.ird.fr/intranet/publi/2022-02/010083939.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2022-02-04 2022-02-04 fdi:010083939 fre