Arctic foxes as ecosystem engineers: benefits to vegetation and collared lemmings through nutrient deposition

• Main Author: Gharajehdaghipoor, Tazarve
• Other Authors: Roth, James (Biological Sciences), Markham, John (Biological Sciences) Brook, Ryan (University of Saskatchewan)
• Format: Master Thesis
• Language: English
• Published: 2015
• Subjects: Ecology; Ecosystem engineer; Arctic fox; Collared lemming; Arctic; Arctic Fox; Churchill; Dicrostonyx richardsoni; Vulpes lagopus
• Online Access: http://hdl.handle.net/1993/31071

I estimated the non-trophic effects of arctic fox (Vulpes lagopus) denning activities on soil nutrient dynamics, vegetation production and quality, snow cover thickness, and their primary terrestrial prey, collared lemmings (Dicrostonyx richardsoni), near Churchill, Manitoba in April, June and August 2014. Arctic foxes increased soil inorganic nitrogen and extractable phosphorous concentration on their dens. This increase in soil nutrient levels resulted in greater vegetation quantity (measured as biomass and cover) and quality (measured as nitrogen content) on dens. Increased vegetation cover, specifically Salix sp. and Leymus mollis cover, positively affected snow cover thickness on dens by trapping blowing snow. Increased snow cover thickness made dens attractive nesting sites to collared lemmings (measured as lemming nest counts). In addition, dens with lemming nests had greater snow cover thickness compared to dens without lemming nests. Greater vegetation quantity and quality on dens could also attract lemmings to dens for winter nesting. February 2016