Impact of deer browsing on plant communities in cutover sites on Anticosti Island

Abstract

Browsing by Anticosti Island's large white-tailed deer (Odocoileus virginianus) population reduces the abundance of the deer's preferred species and increases the abundance of less preferred species. This alteration of plant communities can lead to degradation of deer habitat. However, the centres of large clear-cuts may be spared from deer browsing given that this animal's instincts regarding predation risk impel it to remain near escape cover. This project assessed the impact of high deer populations on plant communities in large clear-cuts harvested by cutting with protection of regeneration and soils (CPRS). To this end, vegetation growing within fenced-off areas was compared with that growing in adjacent unfenced plots following application of large CPRS in 1995 and 1996. The results show that deer browsing does not have an impact on the number of plant species but does dramatically reduce total species cover. Furthermore, although the number of species was the same in the fenced and unfenced plots, some species were only found in one or the other type of plot. Rubus idaeus, Betula papyrifera, Epilobium angustifolium, Abies balsamea, Maianthemum canadense, Cornus Canadensis, and Prunus pensylvanica were all associated with fenced plots, while the cover of true grasses and Cirsium arvense increased in the unfenced plots. We conclude that large CPRS-harvested clear-cuts cannot serve to preserve the initial plant communities on Anticosti Island.