Canada Yew and White-tailed Deer at the Apostle Islands: Summary of Research to Date with Recommendations for Continued Monitoring and Management

Taber, Allison

Reproductive effort and vegetative growth of tagged Canada yew (Taxus canadensis) plants have been measured between 1982 and 2000 on several islands that differ in deer browsing history within the Apostle Islands National Lakeshore. The long-term goals of this research are: 1) to determine the relative importance of seedling recruitment and vegetative growth in the expansion of Canada yew in previously browsed populations following the cessation of browsing and 2) to monitor growth and mortality in browsed versus unbrowsed Canada yew populations. The resulting data are used to answer several questions regarding the long-term impact of deer browsing on Canada yew and the growth and “recovery” of Canada yew populations following cessation of browsing. The fundamental conclusion developed in this report and several publications cited in this report, is that Canada yew and white-tailed deer are incompatible at the Apostle Islands. Several management recommendations are presented for Park Service staff to implement to test some of the hypotheses presented in this report and to continue to monitor the long-term impacts of deer on Canada yew. These recommendations include continuing the long-term monitoring of reproductive effort and vegetative growth of Canada yew on islands currently with and without deer.