Microcrustacean metacommunities in urban temporary ponds

Microcrustaceans have a series of adaptations that allow their development in temporary aquatic environments. The colonization and consequent structuring of the communities in these systems is influenced by several environmental and spatial factors. Among them, urbanization is one of the important structuring factors of these communities. Metacommunity theory is an important tool for assessing how local (e.g. environment, competition and predation) and regional/spatial (e.g. dispersion) factors can influence the structure of communities distributed in patches in an area. We evaluated the diversity of the metacommunity of microcrustaceans in two categories of urban aquatic environments, preserved and constructed, looking for how the environmental and spatial factors influenced their diversity. We also sought to verify which beta diversity mechanism explained the dissimilarity between communities. We hypothesized that the richness of taxa would be greater in aquatic environments of preserved areas and in constructed areas there would be a loss of species, thus generating a beta diversity explained by the nestedness pattern. We sampled temporary environments in an urban area, eight in a preserved and six in a construction area. The results showed a clear difference between the two areas, both in environmental characteristics and in the composition of taxa. In relation to the richness of taxa, the areas did not present significant differences, thus rejecting our first hypothesis. The beta diversity was explained mainly by the turnover mechanism, refuting our second hypothesis. This pattern was mainly explained by the difference in the composition of taxa between the preserved and construction area environments.