Land use changes disrupt streams and affect the functional feeding groups of aquatic insects in the Amazon

Changes in riparian vegetation directly affect the entry of allochthonous material into aquatic systems, which is the main source of food and energy for different functional feeding groups (FFG) of aquatic insects that play important ecological roles in these ecosystems. Thus, reducing the fragmentation of organic matter affecting the energy flow and food network, interfering with important ecosystem processes that sustain biodiversity. We assess the effects of landscape changes on the composition of the FFG of Ephemeroptera, Plecoptera and Trichoptera (EPT) communities in streams from the Eastern Amazon, a region that exhibits a mosaic of multiple land uses with the prevalence of pastures. We expected that shredders and collectors (gatherers and filterers), naturally prevalent in preserved first-order streams, would be more affected by the loss of riparian vegetation due to their higher dependence on allochthonous food sources than other FFG. We sampled 30 Amazonian streams (1st to 3rd orders) located in the Capim River Basin, Paragominas, Pará, Brazil. The environmental predictors affected the FFG of EPT. Shredders, collector-gatherer, and predators were predominant in streams with more forests that had more living trees in the channel. On the other hand, collector-filter were predominant in streams with more exposed soil and higher water temperatures. We conclude that the preservation of riparian zones is important for the preservation of FFG of EPT and highlighting the effectiveness of using these groups as a tool for biomonitoring environmental quality. Implications for insect conservation Our results show that FFG of EPT are affected by environmental conditions. Therefore, the landscape changes caused by the deforestation of the riparian zone imply changes in the composition of the FFG of EPT communities.