Effects of drying and orientation to perennial refuges on aquatic biodiversity across two basins differing in aridity

Abstract Intermittent streams are globally distributed, comprise over half the length of global river network, and expected to become more prevalent. However, most studies intermittent conducted at extremes scale, limited in taxonomic temporal scope, focus exclusively on drying patterns. Here, we assessed how both flow intermittency orientation perennial refuges affect aquatic invertebrates semiaquatic vertebrates across 2 years within two basins differing their aridity. We used loggers characterize wet–dry mapping determine reaches. In winter summer 2015 2016, collected identified visually surveyed vertebrates. Using permutational multivariate analyses variance with distance matrices, found distinct invertebrate communities by basin, class (perennial or intermittent), season, vertebrate between classes seasons arid basin. Invertebrate had higher beta diversity than mesic whereas opposite was true for indicator species all combinations basin class, reaches combined from basins, each some season basins. Flow refuge predictors correlated well communities. did not find nestedness that differed significantly chance response increasing refuges. Lastly, intermittency, were generally important modeling taxon richness densities, densities decreased Collectively, our data suggest harbor unique biodiversity, but also taxa have context‐dependent responses These findings future increases stream likely lead changes high potential loss biodiversity.