Water availability and quality determine temporal synchrony and beta diversity of microcrustaceans in temporary pools

Abstract

Beta diversity patterns have been frequently used to investigate metacommunity structure. The metacommunity concept has focused primarily on the spatial beta component, but part of the unaccounted variation is likely associated with temporal beta patterns. Here, we examined the effect of seasonal variation in water availability on the spatiotemporal assembly of microcrustaceans living in temporary pools. Specifically, we sampled microcrustaceans in 5 pools monthly for 12 mo and tested how temporal fluctuations in physicochemical variables affected beta diversity. We also investigated whether species showed synchronous responses in tracking dry or wet conditions. Our study revealed that only those microcrustacean species associated with the wet season had temporally synchronous population dynamics. However, we did not find population synchrony in the dry season and in those comparisons including all microcrustacean species. Physicochemical variables such as pH, dissolved oxygen, and water transparency explained part of the spatial variation in beta diversity. These results suggest a strong influence of species sorting on metacommunity structure both in space and in time. Extreme climatic conditions, such as water scarcity, could affect population dynamics; thus, linking spatial and temporal patterns will be necessary to disentangle the effects of stochastic processes and environmental filtering on metacommunity dynamics.