Robust metagenomic evidence that local assemblage richness increases with latitude in ground-active invertebrates of North America.

To sample pitfall animals, we filtered storage ethanol and employed metagenomic barcoding methodologies to amplify and sequence extracted DNA from the filtrate for two regions of a mitochondrial gene. We assigned taxonomic names to these sequences at 97% similarity to reference sequences and calculated local taxonomic richness at the levels of species, genus, family, and order. We calculated local species richness for 10 common arthropod taxa and the Annelida and Mollusca. Additionally, we estimated regional species richness using expert-identified samples of three NEON sentinel taxa: Carabidae, Culicidae, and Ixodida. We used generalized linear models to describe the relationships between taxonomic richness and spatial, climatic, and abundance predictor variables.