Filtros ambientais e espaciais em metacomunidades de peixes de lagoas de quatro planícies de inundação neotropicais.

Abstract

The spatial distribution of biological communities may be regulated by environmental and spatial processes and the intensity of these processes depend on the species characteristics, spatial heterogeneity and spatial extent. This this study investigated the importance of environmental and spatial filters in structuring metacommunities of fish in lagoons of four floodplain: Amazonas, Araguaia, Pantanal and Upper Parana River. Fish species were grouped into sedentary and migratory, related to their dispersion ability, but just sedentary species were used because of the low number of migrators. Following hypothesis were tested: i. The spatial distribution of sedentary species is organized according to space limitation; ii. Connectivity in the period of high water, weakens the relative importance of spatial filters in the structure of sedentary communities.The environmental filters were significantly more important in the spatial distribution of sedentary community in at least one of the hydrological periods in the four floodplain. The spatial filters were significant predictors in the spatial distribution of sedentary community in one of the hydrological periods (dry or rain). The first hypothesis was rejected for Amazonas floodplain and accepted for the other floodplains. The second hypothesis was accepted for Amazonas and Araguaia floodplains and rejected for Pantanal and Upper Parana River floodplains. In short, metacommunities of sedentary species are structured primarily according to ecological niche of the species although spatial filters were important due to dispersion limitation.