Spatially varying trophic effects of reservoir-derived plankton on stream macroinvertebrates among heterogeneous habitats within reaches

Abstract Using a stable isotope two- and three-source mixing model, we evaluated trophic contributions of reservoir-derived plankton, epilithon, terrestrial leaves to stream macroinvertebrates at two dam upstream four outlet reaches. We compared different habitat types co-occurring within the reaches: lotic habitat, bar-head lentic bar-tail isolated pond on sandy bars. Filter-feeders, which provide highest did not significantly differ among habitats, whereas collector-gatherers predators differed significantly. Thus, model analysis for indicated lower proportion plankton in than habitat. This difference food source composition was reflected contribution species. Macroinvertebrates habitats fed sources less mixed with plankton; therefore, impact reservoirs indistinctive community level, indicating that can function as refugia mitigate reservoirs. Our findings demonstrate heterogeneity potentially provides foundation determining webs while affecting communities when there is anthropogenic input resources