Range expansion of moose in arctic Alaska linked to warming and increased shrub habitat

PLoS ONE
UAF
By: , and 

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Abstract

Twentieth century warming has increased vegetation productivity and shrub cover across northern tundra and treeline regions, but effects on terrestrial wildlife have not been demonstrated on a comparable scale. During this period, Alaskan moose (Alces alces gigas) extended their range from the boreal forest into tundra riparian shrub habitat; similar extensions have been observed in Canada (Aaandersoni) and Eurasia (Aaalces). Northern moose distribution is thought to be limited by forage availability above the snow in late winter, so the observed increase in shrub habitat could be causing the northward moose establishment, but a previous hypothesis suggested that hunting cessation triggered moose establishment. Here, we use recent changes in shrub cover and empirical relationships between shrub height and growing season temperature to estimate available moose habitat in Arctic Alaska c. 1860. We estimate that riparian shrubs were approximately 1.1 m tall c. 1860, greatly reducing the available forage above the snowpack, compared to 2 m tall in 2009. We believe that increases in riparian shrub habitat after 1860 allowed moose to colonize tundra regions of Alaska hundreds of kilometers north and west of previous distribution limits. The northern shift in the distribution of moose, like that of snowshoe hares, has been in response to the spread of their shrub habitat in the Arctic, but at the same time, herbivores have likely had pronounced impacts on the structure and function of these shrub communities. These northward range shifts are a bellwether for other boreal species and their associated predators.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Range expansion of moose in arctic Alaska linked to warming and increased shrub habitat
Series title PLoS ONE
DOI 10.1371/journal.pone.0152636
Volume 11
Issue 4
Year Published 2016
Language English
Publisher Public Library of Science
Publisher location San Francisco, CA
Contributing office(s) Alaska Science Center Biology WTEB
Description 12 p.
First page e0152636
Country United States
State Alaska
Online Only (Y/N) Y
Additional Online Files (Y/N) N