Taxonomic resolution based on DNA barcoding affects environmental signal in metacommunity structure

Invertebrate communities in freshwater streams form the basis of many biomonitoring protocols that rely on coarse taxonomic resolution. Coarse resolution may group together species with different environmental preferences, masking the relationship between taxonomic composition and environmental variables. Alternatively, closely related species often share similar traits, and therefore, refining taxonomic resolution will not affect, or even may decrease, the strength of relationships between taxa and environment. To test these competing hypotheses, we characterized the metacommunity patterns of 5 orders (Coleoptera, Diptera, Ephemeroptera, Plecoptera, Trichoptera) and 1 subclass (Oligochaeta) of invertebrates in 21 streams in Algonquin Provincial Park, Ontario, Canada. We determined community composition at family, genus, and species (DNA barcode cluster) levels. For each taxonomic level within each order, we computed the amount of variation explained by 20 local environmental and spatial variables...