Variação temporal de Ephemeroptera, Plecoptera e Trichoptera (EPT) com base em sua especificidade ambiental em riachos impactados pela mineração na Amazônia Oriental

Abstract

Knowing aquatic diversity and understanding how different species are distributed in time and space has become one of the main focuses of research in ecology in recent decades. This is mainly due to the rapid environmental changes caused by human activities. In this scenario, aquatic insects of the orders Ephemeroptera, Plecoptera, and Trichoptera (EPT) are used to monitor environmental conditions because they are sensitive to these changes. The intensity of the response depends directly on the breadth of the niche of each taxon given the variability and changes in the habitat. With the general objective of investigating the effects of iron mining based on the environmental specificity of EPT in streams of the Carajás National Forest in Pará, over six years, this dissertation is divided into two chapters. In the first, we classified EPT taxa into generalists and specialists and evaluated whether the estimated abundance and richness of these groups vary according to the level of alteration of the streams impacted by mining activities. In the second, we evaluated the spatial and temporal variation of the beta diversity of generalist and specialist EPT. In both studies, EPT data sampled annually in 24 streams over six years were used in streams conserved and impacted by mining in the Carajás Flona. A total of 49,922 individuals distributed in 59 genera were collected, of which 31 were classified as specialists and 28 as habitat generalists. In the first chapter, we verified that there was a negative effect of mining on the estimated wealth and a positive effect on the abundance of specialist genera. On the other hand, the abundance and estimated wealth of generalists were negatively influenced by the mining effect. In the second chapter, no differences were found in gender composition or heterogeneity between treatments. However, over time, both generalists and specialists changed their composition. Mining affects the communities of EPT generalists and specialists, in particular, specialists from sites impacted by mining that showed an increase in their abundances, possibly due to the expansion of habitat made available by the process of habitat homogenization. For generalists, gender loss was the main component in temporal beta diversity, while specialists showed gender gains and losses. Therefore, mining has affected communities of both generalist and specialist groups over the years, despite their habitat specificity, presenting different patterns of environmental changes.