Fig. 2. Environmental heterogeneity in the Paraná fluvial system in different hydrological phases.

The environmental heterogeneity is expressed as average environmental dissimilarity between sites ($\overline{\mathrm{Ed}}$, gray bars) and the variability (coefficient of variation, CV%) of nine selected abiotic variables among environments. LW low water, LWs low water with sedimentological pulse, HW high water, eHW extraordinary high water.