Aspen coppice with coarse woody debris: a silvicultural system for interior Alaska moose browse production

Abstract

Browse production and use by moose (Alces alces gigas) in interior Alaska was investigated in 4 and 2-year-old quaking aspen (Populus tremuloides) coppice stands following clear-felling without removal of the mature aspen stems. Moose winter browse utilization, as related to distance from cover, coarse woody debris (CWD), and browse species composition, was quantified. Aspen terminal leaders were sampled to relate current annual growth (CAG) dry biomass (g) to leader diameter (mm). Stem density, current annual browse production, and browse use were estimated. Browse use was determined as 1) proportion of aspen stems browsed (stand scale), 2) proportion of browsed leaders per stem (stem scale), and 3) diameter-at-point-of-browsing (leader scale). Aspen sucker density ranged from 23,000-43,000 stems/ha. Terminal leader diameter was found to be a good estimator of individual stem CAG biomass. CWD did not impede moose utilization of stems. Browse use declined from mature stand edge to center (100 m). Beyond 15 m from mature stand edge browse use was low compared to that within 15 m of the stand edge. Clear-felling without removal of stems is a viable silvicultural method to reinitiate seral aspen in lieu of prescribed fire or mechanical treatments on south-facing hillsides.