Scale-Dependent Browsing Patterns on Canada Yew (Taxus canadensis) by White-Tailed Deer (Odocoileus virginianus)
Figure 3
(a–f) Mean cumulative browsing score (±1 SE) for clusters of Canada yew stems in relation to various predictor variables from 24 stands in Marquette and Alger counties, MI, 2001-2002. Cumulative browse scores were based on the proportion of twigs browsed by deer during the previous three winters for each stem in a cluster (1 = <5% twigs browsed, 2 = 6–25%, 3 = 26–50%, 4 = 51–75%, 5 = 76–95%, 6 = >95%). Predictor variables were: (a) Mean length (cm) of individual Canada yew stems; (b) Location of stems in relation to Canada yew patch edge: No Patch = stems that do not form a discrete patch, Edge = stems <1 m from the edge of the patch, and Interior = stems ≥1 m from the edge of the patch; (c) slope and aspect of the site surrounding the Canada yew stems; (d) percent forest canopy cover of the site surrounding the Canada yew stems; (e) composition of forest surrounding the Canada yew stems (DEC = <25% conifer, MIXED = ≥25% conifer); (f) percent Canada yew cover in the forest stand, based on 11 m radius plots. See Section 2 for additional details about predictor variables.
