Response to environmental, spatial, and temporal mechanisms of the phytoplankton metacommunity: comparing ecological approaches in subtropical reservoirs

Our objective was to evaluate the effect of environmental, spatial, and temporal predictors on different ecological approaches in phytoplankton metacommunity of two subtropical reservoirs. Our hypothesis was that the morphological structure, represented by morphological traits, would be related to both environmental and spatial factors, while the functional structure, represented by the physiological, ecological, and morphological traits, would be related to environmental factors. We also test the temporal factor for both approaches. Sampling was performed in two Brazilian subtropical reservoirs along six sampling periods. We applied the morphology-based functional classification (MBFG) and the classification based on functional group (FG) as surrogates to phytoplankton metacommunity and performed the partition variation to investigate the influences of different predictors. We found spatial and temporal variability of MBFG and FG, and although the metacommunity models presented weak relations, the environmental, spatial, and temporal processes appear to influence the phytoplankton morpho-functional structure along the longitudinal axis reservoirs. However, the relative importance of these processes seems to depend on the type of functional attribute evaluated since the MBFGs were related to the spatial and temporal predictor, while the FGs were associated with environmental, spatial, and temporal predictors.