Eight legs in the North: The ecological structure of Arctic spider assemblages

Canada's Arctic is home to a diverse and important arthropod fauna, but one that is poorly understood. As part of the Northern Biodiversity Program, spiders (Araneae) were collected in 12 sites across northern Canada, and the structure of the ground-dwelling fauna was quantified.  Spiders were sampled from pan and pitfall traps placed in open tundra habitats using a hierarchical sampling design that covered 30 degrees of latitude and 80 degrees of longitude. Over 23,000 individuals were collected, representing over 300 species from 14 families.   The fauna was largely structured according to broad ecoclimatic zones, but a distinct longitudinal gradient was also uncovered. This research has vastly improved our knowledge about biodiversity of spiders in the north, and provides an important baseline for future monitoring efforts and studies of northern arthropods as we face a future that will bring unprecedented  change to the Arctic.