Browse Production and Its Use by Moose and Snowshoe Hares at the Kenai Moose Research Center, Alaska

A 4-year study conducted at the Moose Research Center (MRC) on the Kenai National Wildlife Refuge, Alaska evaluated the effect of different densities of moose (Alces alces) on paper birch (Betula papyrifera) production and use. Production and use of quaking aspen (Populus tremuloides) and willow (Salix spp.) were also estimated and the impact of snowshoe hares (Lepus americanus) on paper birch was evaluated. The study was conducted in 4 2.6-km2 enclosures at the MRC where moose densities ranged from 1,237 to 5,851 moose-days/pen/winter period. Paper birch produced an average of 102 kg/ha in the 4 enclosures whereas willow and aspen together produced only 3.7 kg/ha. During the 1st 3 years there was a significant difference in per-plant production among 5 important vegetative types. Use by moose at higher densities affected mean plant production the 3rd and 4th years. Birch use ranged from 31.8 to 83.3% of current annual production. During the 4 years, snowshoe hares browsed a greater percentage of tagged plants than did moose. Sixty-five percent of the birch plants browsed by hares were less than 1.5 m tall and 62% of those browsed by moose were taller than 1.5 m. Birch plants browsed in a given year were shorter on the average the following growing season. Seventy percent of the willow and 58.7% of the aspen plants were browsed during winter. J. WILDL. MANAGE. 47(2):486-496 I evaluated the effects of forage use by moose at the Moose Research Center (MRC) on the Kenai National Wildlife Refuge (KNWR), Alaska from October 1971 through May 1975. The primary objective was to evaluate the effect of different moose densities on production and use of paper birch. Although quaking aspen and willow occur at the MRC, paper birch was the most abundant forage species and LeResche and Davis (1973) found that it composed the bulk of the moose's year-round diet. Snowshoe hares were near a cycle high when the study began and were having an obvious effect on the vegetation. Secondary objectives were to estimate production of aspen and willow and their use by herbivores, and to evaluate the impact of snowshoe hares on paper birch. P. D. Arneson, A. W. Franzmann, and R. E. LeResche of the Alaska Department of Fish and Game; J. B. Hakala, J. B. Monnie, and R. K. Seemel of the Kenai National Wildlife Refuge; and R. B. Finley, Denver Wildlife Research Center, provided logistic support and guidance for the study. I thank S. Blackhall, T. Corr, R. Pietron, D. Porter, and T. Spraker for field assistance. The manuscript was reviewed by C. P. Stone, National Park Service; A. W. Franzmann, Alaska Department of Fish and Game; T. Bailey and E. Bangs, Kenai National Wildlife Refuge; E. S. Telfe , Canadian Wildlife Service; J. 0. Wolff, University of Virginia; and W. L. Regelin, Denver Wildlife Research Center. The Moose Research Center is a cooperative research project between the Alaska Department of Fish and Game and the U.S. Fish and Wildlife Service.