Conifer Release Alternatives Increase Aspen Forage Quality in Northwestern Ontario

Conifer release reduces browse availability and moose (Alces alces) use of treated areas for up to 4 years posttreatment; however, it has been unclear how release affects forage quality. We determined percent digestible dry matter (DDM) and percent digestible protein (DP) of trembling aspen (Populus tremuloides), beaked hazel (Corylus cornuta), and red raspberry (Rubus idaeus) collected during mid-July, 2 growing seasons after the following operational conifer release treatments were applied: (1) Vision (r) herbicide (active ingredient: glyphosate), (2) Release (r) herbicide (active ingredient: triclopyr), (3) cutting (brush saw, Silvana Selective), and (4) no treatment (control). No differences (P > 0.05) in bovine serum albumin (BSA) precipitation were found among the forage species tested. Differences (P < 0.05) in DDM between hazel (low) and the other 2 species (higher) were common, but only trembling aspen, which had the highest DDM and DP, showed differences among treatments (P < 0.05). When compared with controls, aspen DDM was 5-11% and DP was 34-49% greater on released plots. Although not statistically significant, DP was consistently higher for hazel and raspberry on herbicide-released plots. The lack of differences in DDM and DP among treatments for 2 of the 3 species examined suggests that, through time, biomass availability of forage species known to be used by ungulates continues to be a realistic way to predict the effects of conifer-release treatments on ungulate forage.