title: Long-term monitoring at multiple trophic levels suggests heterogeneity in responses to climate change in the Canadian Arctic tundra.
abstract: Arctic wildlife is often presented as being highly at risk in the face of current climate warming. We use the long-term (up to 24 years) monitoring records available on Bylot Island in the Canadian Arctic to examine temporal trends in population attributes of several terrestrial vertebrates and in primary production. Despite a warming trend (e.g. cumulative annual thawing degree-days increased by 37% and snow-melt date advanced by 4-7 days over a 23-year period), we found little evidence for changes in the phenology, abundance or productivity of several vertebrate species (snow goose, foxes, lemmings, avian predators and one passerine). Only primary production showed a response to warming (annual above-ground biomass of wetland graminoids increased by 123% during this period). We nonetheless found evidence for potential mismatches between herbivores and their food plants in response to warming as snow geese adjusted their laying date by only 3.8 days on average for a change in snow-melt of 10 days, half of the corresponding adjustment shown by the timing of plant growth (7.1 days). We discuss several reasons (duration of time series, large annual variability, amplitude of observed climate change, nonlinear dynamic or constraints imposed by various rate of warming with latitude in migrants) to explain the lack of response by herbivores and predators to climate warming at our study site. We also show how length and intensity of monitoring could affect our ability to detect temporal trends and provide recommendations for future monitoring.
authors.affiliation: Département de biologie and Centre d'études nordiques, Université Laval, 1045 avenue de la Médecine, Pavillon Vachon, Quebec City, Quebec, Canada G1V 0A6. gilles.gauthier@bio.ulaval.ca
authors.forename: Gilles
authors.initials: G
authors.lastname: Gauthier
authors.forename: Joël
authors.initials: J
authors.lastname: Bêty
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Cadieux
authors.forename: Pierre
authors.initials: P
authors.lastname: Legagneux
authors.forename: Madeleine
authors.initials: M
authors.lastname: Doiron
authors.forename: Clément
authors.initials: C
authors.lastname: Chevallier
authors.forename: Sandra
authors.initials: S
authors.lastname: Lai
authors.forename: Arnaud
authors.initials: A
authors.lastname: Tarroux
authors.forename: Dominique
authors.initials: D
authors.lastname: Berteaux
mesh_terms: D000818:Animals; D001110:Arctic Regions; D003411:Arvicolinae / Q000502:physiology*; D001717:Birds / Q000502:physiology*; D002170:Canada; D057231:Climate Change; D020387:Food Chain; D005589:Foxes / Q000502:physiology*; D011157:Population Dynamics; D013696:Temperature; D013997:Time Factors
keywords: Arctic vertebrates; climate change; ecological response; long-term monitoring; trophic interaction; tundra food web