Does Balsam Fir (Abies balsamea) Facilitate the Recruitment of Eastern Hemlock (Tsuga canadensis)?
Eastern hemlock (Tsuga canadensis) was a major component of mesic forests in the Upper Great Lakes region, but presently persists in only a few locations. Many of these stands experience poor regeneration due to herbivory by white-tailed deer (Odocoileus virginianus), suggesting that hemlock will become progressively less common in these stands. We tested the hypothesis that balsam fir (Abies balsamea) facilitates establishment of eastern hemlock at 11 sites in northern Wisconsin. Hemlock saplings are three times as dense and twice as tall when growing within patches of balsam fir compared to growing outside such patches. Hemlock saplings growing outside balsam fir patches are also four times as likely to exhibit deer browsing damage as those growing inside. These results suggest that patches of balsam fir create a physical or visual barrier to deer and thus provide a refuge for hemlock saplings from white-tailed deer browsing. Because balsam fir saplings are much more abundant than hemlock in northern Wisconsin forests and establish on a wider range of sites, foresters could use patches of balsam fir to facilitate local hemlock establishment and so promote restoration of this important forest type.
Borgmann, K. L.,
Waller, D. M.,
& Rooney, T. P.
(1999). Does Balsam Fir (Abies balsamea) Facilitate the Recruitment of Eastern Hemlock (Tsuga canadensis)?. The American Midland Naturalist, 141 (2), 391-397.