Spatio-temporal beta diversity of specialist and generalist aquatic insects in streams altered by mining activities in eastern Amazonia

Over time, the species comprising aquatic communities disperse and form new communities and/or alter existing ones. These changes are a result of environmental factors that directly influence the niche breadth for each taxon. Therefore, understanding the dynamics of aquatic communities to better comprehend the effects of anthropogenic activities. In this study, we assessed the spatio-temporal beta diversity of aquatic insect genera of Ephemeroptera, Plecoptera, and Trichoptera generalists and habitat specialists in streams affected by mining activities and control streams in eastern Amazonia. We tested the hypotheses that the beta diversity of specialists would exhibit greater variation over time in streams impacted by mining, while the beta diversity of generalists would over time. We sampled in 24 streams (12 streams influenced by mining and 12 control). Over six years, the genera found were classified into 31 specialists and 28 generalists. Beta diversity varied among the streams, with changes observed in the community composition for both generalists and habitat specialists over time. For the generalists, the loss of genera was the main component in the temporal beta diversity, while the specialists’ showed gains in some genera and losses in others. Environmental changes in mining-altered streams may decrease the colonization of new genera, leading to decreased diversity and alterations in ecological balance over time.