Metabarcoding Inventory of an Arctic Tundra Soil Ecosystem Reveals Highly Endemic Communities

Biodiversity surveys of Arctic soil ecosystems are limited. Here, we provide a sequence-based inventory of soil fauna from an Arctic tundra ecosystem near Iqaluktuutiaq (Cambridge Bay), Nunavut. Invertebrate communities were extracted from soil at three sites with vegetation cover and three non-vegetated sites and inventoried using 18S metabarcode sequencing. A total of 361 Amplicon Sequence Variants (ASV) were identified and assigned to the closest matching taxonomic orders, most of which belonged to the Nematoda and Arthropoda. Vegetated soils showed no significantly higher ASV richness relative to non-vegetated soils although they contained a significantly higher diversity of arthropod taxa including insects, mites and springtails. The majority of taxa were found only at a single location and communities were distinct between soils even for sites with vegetation cover, suggesting that belowground species richness in Arctic tundra habitats is highly endemic and heterogeneous. Preserving endemicity is essential for Inuit communities who rely on intact tundra ecosystems for their health and wellbeing.