Spatiotemporal ecological drivers of an aquatic plant community in a temporary tropical pool

Abstract

Ecological processes that extend over time and space organize plant communities, producing different spatiotemporal patterns of species aggregation (or non-aggregation). To investigate whether the spatiotemporal distribution patterns of the species are generated by interspecific competition and/or environmental filtering, we investigated the organization of an aquatic plant community in a temporary pool in the semiarid region of NE Brazil. For seven months (during the rainy season), we sampled aquatic plants along transects in the pool and measured limnological parameters. The spatial structure of the community changed significantly over time. The input and permanence of species in the community varied according to the stage of flooding of the pool. This leads to the expectation that the species would have overlapping niches, causing interspecific competition to increase and exclude less efficient competitors. Indeed, we found that the species coexisting in the pool were only slightly phylogenetically related, an evidence of interspecific competition. Therefore, in the temporary pool, the spatiotemporal organization of the aquatic plant community appears to be driven by simultaneous action of ecological abiotic and biotic processes that operate in an antagonistic fashion.