The decline of moose (Alces alces) fitness : a result of poor browse availability and high browsing pressure? - A comparative study of two Norwegian Moose ranges
Master thesis
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Date
2013-08-26Metadata
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- Master's theses (INA) [593]
Abstract
There has been a recorded difference in carcass weights among moose (Alces alces) on the
western side of the Oslo fjord compared to the eastern side over the last decades. So far, this
reduction has been credited to density-dependent limitations in browse availability leading to
a higher browsing pressure. I compared browse availability and pressure on clearcuts in two
ranges with differences in moose fitness. I found that the western ranges have more preferred
browse, but I did not find a significant difference in the availability of birch (Betula spp.).
Browsing pressure was significantly higher in the east on older clearcuts, but the difference
disappeared on younger clearcuts. In the east, older clearcuts were more heavily browsed than
younger, but this was not the case in the west. This study concludes that browse availability
today is not the reason for the difference in carcass weights. The problem must therefore rest
with the western moose population, and needs further investigation. A culling of the
population in a trial area could be conducted to further investigate this matter, or we have to
wait until the fertile of the 1950's sites that led to the increase in moose fitness then, are
logged again.