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Arctic greening from warming promotes declines in caribou populations

The migratory tundra caribou herds in North America follow decadal population cycles, and browsing from abundant caribou could be expected to counteract the current climate-driven expansion of shrubs in the circumpolar tundra biome. We demonstrate that the sea ice cover in the Arctic Ocean has provi...

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Autores principales: Fauchald, Per, Park, Taejin, Tømmervik, Hans, Myneni, Ranga, Hausner, Vera Helene
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Association for the Advancement of Science 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5406139/
https://www.ncbi.nlm.nih.gov/pubmed/28508037
http://dx.doi.org/10.1126/sciadv.1601365
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author Fauchald, Per
Park, Taejin
Tømmervik, Hans
Myneni, Ranga
Hausner, Vera Helene
author_facet Fauchald, Per
Park, Taejin
Tømmervik, Hans
Myneni, Ranga
Hausner, Vera Helene
author_sort Fauchald, Per
collection PubMed
description The migratory tundra caribou herds in North America follow decadal population cycles, and browsing from abundant caribou could be expected to counteract the current climate-driven expansion of shrubs in the circumpolar tundra biome. We demonstrate that the sea ice cover in the Arctic Ocean has provided a strong signal for climate-induced changes on the adjacent caribou summer ranges, outperforming other climate indices in explaining the caribou-plant dynamics. We found no evidence of a negative effect of caribou abundance on vegetation biomass. On the contrary, we found a strong bottom-up effect in which a warmer climate related to diminishing sea ice has increased the plant biomass on the summer pastures, along with a paradoxical decline in caribou populations. This result suggests that this climate-induced greening has been accompanied by a deterioration of pasture quality. The shrub expansion in Arctic North America involves plant species with strong antibrowsing defenses. Our results might therefore be an early signal of a climate-driven shift in the caribou-plant interaction from a system with low plant biomass modulated by cyclic caribou populations to a system dominated by nonedible shrubs and diminishing herds of migratory caribou.
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spelling pubmed-54061392017-05-15 Arctic greening from warming promotes declines in caribou populations Fauchald, Per Park, Taejin Tømmervik, Hans Myneni, Ranga Hausner, Vera Helene Sci Adv Research Articles The migratory tundra caribou herds in North America follow decadal population cycles, and browsing from abundant caribou could be expected to counteract the current climate-driven expansion of shrubs in the circumpolar tundra biome. We demonstrate that the sea ice cover in the Arctic Ocean has provided a strong signal for climate-induced changes on the adjacent caribou summer ranges, outperforming other climate indices in explaining the caribou-plant dynamics. We found no evidence of a negative effect of caribou abundance on vegetation biomass. On the contrary, we found a strong bottom-up effect in which a warmer climate related to diminishing sea ice has increased the plant biomass on the summer pastures, along with a paradoxical decline in caribou populations. This result suggests that this climate-induced greening has been accompanied by a deterioration of pasture quality. The shrub expansion in Arctic North America involves plant species with strong antibrowsing defenses. Our results might therefore be an early signal of a climate-driven shift in the caribou-plant interaction from a system with low plant biomass modulated by cyclic caribou populations to a system dominated by nonedible shrubs and diminishing herds of migratory caribou. American Association for the Advancement of Science 2017-04-26 /pmc/articles/PMC5406139/ /pubmed/28508037 http://dx.doi.org/10.1126/sciadv.1601365 Text en Copyright © 2017, The Authors http://creativecommons.org/licenses/by-nc/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license (http://creativecommons.org/licenses/by-nc/4.0/) , which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.
spellingShingle Research Articles
Fauchald, Per
Park, Taejin
Tømmervik, Hans
Myneni, Ranga
Hausner, Vera Helene
Arctic greening from warming promotes declines in caribou populations
title Arctic greening from warming promotes declines in caribou populations
title_full Arctic greening from warming promotes declines in caribou populations
title_fullStr Arctic greening from warming promotes declines in caribou populations
title_full_unstemmed Arctic greening from warming promotes declines in caribou populations
title_short Arctic greening from warming promotes declines in caribou populations
title_sort arctic greening from warming promotes declines in caribou populations
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5406139/
https://www.ncbi.nlm.nih.gov/pubmed/28508037
http://dx.doi.org/10.1126/sciadv.1601365
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