Scarabotti P. A. auteur aut IRD Demonte L. D. auteur aut IRD Pouilly Marc auteur aut IRD text journalArticle eng text/pdf born digital access We applied a multiscale approach to understand the patterns of longitudinal, lateral, and temporal variability in fish assemblage structure of a large floodplain river and explored their relationships with climatic seasonality, hydrological variability, and floodplain geomorphology. We studied the fish assemblage structure of 35 connected lakes along a 600-km section of the Parana River over 5 y. Longitudinal changes in fish assemblage structure were associated with a latitudinal climatic gradient, whereas temporal changes were associated with climatic seasonality and hydrological variability. Longitudinal and seasonal changes in assemblage structure were probably based on different thermal preferences of species that migrate seasonally along the main river axis. Extraordinary floods in summer promoted downstream dispersal of several species, which increased similarity between downstream and upstream regions. Thermal seasonality of this subtropical system was a strong factor driving temporal changes in assemblage structure, and the effects of the hydrological regime largely depended on flood pulses coincident with periods of warmer temperatures. Fish assemblages varied secondarily along a lateral gradient represented by types of geomorphic units distributed in the floodplain. The geomorphic units generated patchy environmental heterogeneity at the landscape scale that resulted in discontinuous patterns of fish assemblage structure. Assemblage composition was more similar among lakes belonging to similar geomorphic units but situated at geographically distant regions than among lakes belonging to different geomorphic units situated in the same region. Therefore, patterns in fish assemblage variation at regional and landscape scales appear to be determined largely by the dispersal and selection of suitable habitats by fish across the hierarchy of spatial and temporal scales. specialized flood pulse temperature dispersal neotropical fish community ecology ARGENTINE PARANA BASSIN VERSANT ZONE SUBTROPICALE 062 036 36 3 653-668 2017 2161-9549 https://www.documentation.ird.fr/hor/fdi:010070901 10.1086/693441 2161-9549 [F B010070901] https://www.documentation.ird.fr/hor/fdi:010070901 https://www.documentation.ird.fr/intranet/publi/2017/09/010070901.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2017-10-03 2023-07-11 fdi:010070901 fre