Browse biomass removal and nutritional condition of moose Alces alces
C. Tom Seaton, Thomas F. Paragi, Rodney D. Boertje, Knut Kielland, Stepehn DuBois & Craig L. Fleener
We present methodology for assessing browse removal to help evaluate resource limitation among moose Alces alces populations in large, potentially remote areas of boreal forest. During 2000-2007, we compared proportional removal (ratio of browse consumption to browse production) in eight areas of Interior Alaska, USA, with multi-year twinning rates of the respective moose populations. Several prior studies concluded that twinning rate provided an index of the nutritional condition of moose. We theorized that a plant-based sampling of proportional use of browse by moose in late winter would inversely correlate with the nutritional condition of moose. We sampled willow Salix spp., quaking aspen Populus tremuloides, balsam poplar P. balsamifera and Alaska paper birch Betula neoalaskana, i.e. plants with current annual growth (CAG) between 0.5 and 3.0 m above ground. We estimated the biomass of CAG and biomass removed by moose based on bite diameters and diameter-mass regressions specific to each browse species. Mean browse removal by moose varied among study areas from 9 to 43% of CAG. Moose twinning rate (range: 7-64%) was inversely correlated with proportional browse removal by moose (Spearman’s rho = -0.863, P < 0.005). Proportional browse removal appeared useful in linking foraging ecology and population dynamics of moose in Alaska, and the technique may be used to quantify resource limitation in moose populations inhabiting boreal forest in a broader geographic region.
Key words: Alces alces, browse, forage, Interior Alaska, moose, moose density, twinning, willow
C. Tom Seaton, Thomas F. Paragi & Rodney D. Boertje, Alaska Department of Fish and Game, 1300 College Road, Fairbanks, Alaska 99701-1599, USA - e-mail addresses: tom.seaton@alaska.gov (C. Tom Seaton); tom.paragi@alaska.gov (Thomas F. Paragi); rod.boertje@alaska.gov (Rodney D. Boertje)
Knut Kielland, Institute of Arctic Biology, University of Alaska Fairbanks, Alaska 99775, USA - e-mail: ffkk@uaf.edu
Stephen D. DuBois, Alaska Department of Fish and Game, P.O. Box 605, Delta Junction, Alaska 99737-0605, USA - e-mail: steve.dubois@alaska.gov
Craig L. Fleener*, Council of Athabascan Tribal Governments, 283 East Second Avenue, Fort Yukon, Alaska 99740, USA - e-mail: craig.fleener@alaska.gov
*Present address: Alaska Department of Fish and Game, P.O. Box 115526, Juneau, Alaska 99811-5526, USA
Corresponding author: C. Tom Seaton
Received 22 January 2010, accepted 27 October 2010
Associate Editor: Erlend B. Nilsen
Wildl. Biol. 17: 55-66 (2011)
DOI: 10.2981/10-010
© Wildlife Biology, NKV
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