A landscape is comprised of patches of habitat that influence the distribution, abundance, and movement of wildlife (see review by Franklin and Forman, 1987). Patch size refers to the size of the stand or patch of forest following a disturbance. Gap-type disturbances create a forest of small patches, while stand-replacing disturbances, such as fires, make larger ones. Table 2 presents the characteristics of patch sizes created by the most important natural disturbances in the model forest - wildfire and Spruce Budworm. Values are taken from the literature for New Brunswick (Wein and Moore, 1977) and the southern boreal forest (Dansereau and Bergeron, 1991). Values for Spruce Budworm are from Blais (1983). In the Fundy Model Forest, along the Fundy coast, we consider Spruce Budworm to be a gap-type disturbance. The dominant tree is Red Spruce, which requires several years of defoliation to cause mortality. At a stand level, it takes many years for the stand to open and die from Spruce Budworm attack and there are always survivors. The percentage of mortality is highly variable. Although it is not classic gap-type pattern, it fits this pattern better than the stand replacing model (Gordon, 1996).
Based on this type of information, we conclude that forests should be managed for either gap or stand-replacing disturbance regimes. The division should be done first along the basis of ecodistricts. Second, the forest should be subdivided into vegetation types (forest types) with an aim to maintain forest types that exist because of gap-type disturbance. In all gap-type stands, the aim should be to maintain a closed-canopy cover, a mixed-age distribution of overstory trees and sufficient regeneration to restock the forest. The aim should also be to maintain a mix of species characteristic of the stand. For example, a coastal forest that is characteristically 60% Red Spruce and 40% Yellow Birch should be selection harvested to maintain that relative abundance. In addition, there should be no conversion of mixed wood forests to conifer-dominated forests.
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