Padrão de distribuição de larvas de EPT (Ephemeroptera, Plecoptera, Trichoptera) em riachos na Amazônia Oriental

Abstract

Dispersal is the movement of organisms between habitats in the landscape. It is essential for the establishment of species in new locations and for the maintenance of genetic diversity in the region. Its efficiency depends on the dispersal capacity of individual species, environmental variables and the distance between habitats. The mechanisms of community structuring and anthropogenic impacts on aquatic invertebrates have been assessed using approaches based on species' functional traits, but the use of this method to determine species' dispersal potential is still understudied. Therefore, the dispersal potential of most species is determined indirectly based on functional traits and mainly using expert knowledge. Based on this scenario, the aim of this dissertation was to evaluate the dispersal pattern of EPT larvae (Ephemeroptera, Plecoptera and Trichoptera) and attempt to classify the dispersal potential of genera based on functional dispersal traits and relate these traits to environmental variables. The dissertation is divided into two chapters. In Chapter 1, we examine how functional dispersal traits of EPT larvae are related to environmental conditions of rivers in the eastern Amazon. Most of the traits and their categories were negatively or positively related to some of the nine physicochemical variables selected in the study. Thus, we confirm the fact that environmental conditions influence the composition of functional dispersal traits. In Chapter 2, we classify the dispersal potential of the genera of EPT larvae based on the functional dispersal traits and after consultation with experts of each order. The Ephemeroptera was the order with the most genera with high dispersal potential, while the Plecoptera genera had medium and low values for dispersal. The Trichoptera genera had very different values for dispersal potential. We also investigated whether the dispersal ability of EPT larval genera was reflected in their abundance and prevalence in the rivers of eastern Amazonia, which was not confirmed. In our study, we found that functional traits, whether related to dispersal or not, are excellent tools to be used as proxies.