Haida Gwaii Case Study

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Haida Gwaii is often referred to as the “The Canadian Galapagos” with over 6800 species of flora and fauna and presence of more unique subspecies than any other areas in Canada of equal size (Gaston, Golumbia, Martin & Sharpe, 2008). Haida Gwaii is located 80 km west of the mainland of British Columbia and is the largest and most isolated archipelago located on the west coast of Canada (Stockton, Allombert, Gaston & Martin, 2005). As the archipelago is within close proximity of the Pacific Ocean, the climate is a cool temperate, oceanic, humid to perhumid type that is largely moderated by movement of moist air masses off the Pacific Ocean (Banner et al, 2014). This climate gives rise to a temperate rainforest biome, which results in a plant …show more content…
A study done in Laskeek Bay on East Limestone and Reef Island looked at the effect of Sitka-black tailed deer on the Sitka spruce tree. The study found that while the deer do like to browse the younger spruce seedlings, once the apex of the tree exceeds 1.2 m in height, the tree is able to escape the deer (Vila, Torre, Guibal & Martin, 2003a). However, in the presence of deer it takes 13 – 18 years for the young spruce to reach the necessary height, this is significantly longer than in areas without deer, where it takes only 5 years (Vila et al., 2003a). A similar study looking at the effects of deer on western hemlock found that western hemlock is more vulnerable to deer browsing than the spruce. Western hemlock has a higher browse-line because even when the apical height has exceeded the browsing limit, the deer are still able to pull down the branches due to the western hemlock’s flexible stem (Vila, Torre, Martin & Guibal, 2003b). As a result, it takes about 19 years for the young western hemlock to reach 1.2 m as opposed to 5 years for a non-browsed western hemlock (Vila et al., 2003b). However, despite the deer slowing the growth of the Sitka spruce and the western hemlock, the abundance of these tree species has actually increased since the introduction of deer to the archipelago (Gaston et al., 2009). In contrast, there has been a depletion in young redcedars present in old-growth forests throughout the archipelago, and studies suggest that deer browsing is the reason behind this (Stroh et al., 2008). The Western redcedar is tree species is most vulnerable to high deer densities as it is palatable year round (Stroh et al., 2008). Recently, a study on Graham Island found that under current conditions it could take over 50 years for redcedar seedlings to reach the height of the browse

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