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Publications - Plant ecology
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Stephen A. Stockton, Sylvain Allombert, Anthony J. Gaston, Jean-Louis
Martin, 2005, A natural experiment on the effects of high deer densities on the native
flora of coastal
temperate rain forests, Biological Conservation 126 (2005) 118–128 – PDF
Abstract: The
introduction of Sitka black-tailed deer (Odocoileus
hemionus sitkensis Merriam)
to Haida Gwaii (Queen Charlotte Islands, BC, Canada) in the late 19th century, provided
an opportunity to understand the long-term effects of deer populations on the
vegetation of
temperate rain forests in the absence of their natural predators wolves (Canis lupus L.), and cougars (Puma concolor L.). Using seven small islands with different browsing histories (no deer, deer for <20 years, deer for
>50 years), we tested the long-term effects of high deer densities on plant
cover and species richness in the understorey of forest interior and forest
edge habitats. Overall vegetation cover exceeded 80% in the lower vegetation
layers on islands without deer and was less than 10% on the islands with deer
for more than 50 years. Although overall plant species richness was similar on
islands with or without deer, plant species richness at the plot scale (314m2) was reduced by 20–50% on islands
with deer for >50 years. The differences were most pronounced for the
species rich edge communities and among herb and shrub species. These results
suggest that in the absence of predators, deer have the potential to greatly
simplify the forest ecosystem.
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Christophe Baltzinger, Jean-Louis Martin, 2002, Interactions among deer browsing,
hunting and tree regeneration, Can. J. For. Res. 32: 1254–1264
(2002) – PDF
Abstract: The intentional removal or
addition of species or specific human impacts on ecosystems trigger changes
that can help us understand species interactions. In many temperate forests,
deer populations are increasing and so is the need to understand how they
influence ecosystems. We took advantage of the introduction of Sitka black-tailed deer (Odocoileus
hemionus sitchensis Merriam) to the Queen Charlotte Islands (Haida Gwaii), British Columbia, Canada, to study how hunting pressure
affects the impact of deer on tree regeneration after logging. We show that
although the regeneration of western redcedar (Thuja plicata Donn ex D.
Don) is drastically reduced in presence of deer, regeneration is better and
browsing stress lower, in areas where deer are more exposed to hunting. Similar
effects of accessibility for hunters are observed on browsing stress of Sitka spruce (Picea sitchensis (Bong.)
Carrière). Western hemlock (Tsuga heterophylla (Raf.) Sarg.) is not
significantly affected, and its regeneration is not correlated to hunting. We
suggest that the effect of hunting on tree regeneration could be explained by
the incidence of hunting on deer behaviour rather than by the actual number of
deer killed by hunters. These results suggest that the future occurrence of
redcedar stands in second-growth forests on this archipelago may depend on the
amount and distribution of deer hunting.
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