What If Gone

Species → Arctic Fox

Arctic Fox

Vulpes lagopus

on the order of several hundred thousand individuals globally (stable…
Extinction risk Least Concern
Arctic environmentEcosystem engineerNutrient cyclingClimate change
Arctic Fox (Vulpes lagopus)
Photo: Stephan Sprinz, Wikimedia Commons (CC BY 4.0)

What if it disappeared?

Impact Moderate
Ongoing

The feces, urine, and prey remains that accumulate around an Arctic fox den enrich the soil enough to grow nearly three times more vegetation than elsewhere on the tundra — a fertile island in an otherwise nutrient-poor ecosystem.

Documented
Detail

Gharajehdaghipour, T., Roth, J.D., Fafard, P.M. et Markham, J.H. (2016). Arctic foxes as ecosystem engineers: increased soil nutrients lead to increased plant productivity on fox dens. Scientific Reports, 6, 24020.

Soil measurements near Churchill, Manitoba: up to 242% more inorganic nitrogen and 1,195% more extractable phosphorus at dens than at nearby control sites, depending on the season. Because dens are scarce and reused by successive generations of foxes for decades, these fertile islands remain in place long after a single family has moved on.

In Manitoba

This more abundant vegetation in turn attracts more wildlife: fox dens receive significantly more visits and more different species than control sites — including caribou, likely drawn by the resurgent greenery.

Documented
Detail

Zhao, S.T., Johnson-Bice, S.M. et Roth, J.D. (2022). Foxes engineer hotspots of wildlife activity on the nutrient-limited Arctic tundra. Global Ecology and Conservation, 40, e02310.

Monitoring of 12 natal dens and adjacent control sites over two years. The fox's effect on the tundra doesn't stop at vegetation, then: it ripples out to the animal community that depends on it, predators and herbivores alike — somewhat like a watering hole that concentrates life around it in a desert.

By extrapolation

If the species keeps losing ground to the red fox and to weakening rodent cycles, fewer new dens would be created or maintained — but the fertile islands already in place, some decades old, could keep influencing local vegetation long after the foxes that shaped them are gone.

Extrapolated
Detail

Extrapolation à partir de Gharajehdaghipour et al. (2016) et des données de l'UICN sur le déclin régional du renard arctique en Fennoscandie, sans mesure directe de ce qui advient d'un réseau de terriers après l'abandon durable d'un site.

Active dens continue to receive fresh nutrient inputs; an abandoned den, by contrast, no longer receives them, but its soil stays enriched for an indeterminate time. How quickly an abandoned fertile island reverts to nutrient-poor tundra hasn't been directly measured.

What's missing to confirm it: Long-term monitoring of abandoned dens would confirm how long their fertilizing effect persists once foxes stop occupying them.

Documentation

Last verified: August 14, 2026

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