Twentieth century warming allowed moose to colonize the Alaskan tundra
|Alaskan bull moose [Credit: WikiCommons]|
In the tundra landscape characterized by very short plants, moose must forage on shrubs sticking up above the snow during winter to survive. The authors of the present study therefore wanted to investigate whether a lack of available shrub vegetation was an alternative explanation for the previous absence of moose in the tundra. They used recent changes in shrub cover and relationships between shrub height and summer temperature to estimate the available moose habitat in Arctic Alaska around 1860, to compare it to that available in 2009.
The average shrub height in 1860 is only an estimate, which is a limitation of the study. Nonetheless, the study provides evidence that shrub availability may explain the 20th century colonization of the tundra by moose. The authors suggest that the northward shift of moose in Alaska by hundreds of miles may be one of the most dramatic wildlife changes linked to climate change.
Ken Tape notes, "Although scientists have been anticipating changes to wildlife in response to the observed changes climate and vegetation of the Arctic, this is one of the first studies to demonstrate it. We showed that the large-scale northward shift of moose was likely in response to their increasing shrub habitat in the tundra."
Source: PLOS [April 14, 2016]