Forests occupy almost 90% of the Gwaii Haanas landscape.
Classic coastal rainforest, dominated by large western hemlock, Sitka spruce and red cedar comprise the bulk of Gwaii Haanas’ low elevation forest on the leeward side of the archipelago.
On the windward coast, extreme exposure to winds and wet conditions result in a dominance of stunted trees and vegetation.
Understory vegetation has been greatly influenced by the presence of introduced Sitka black-tailed deer.
In many of the cathedral-like old growth forest areas, deer browse has substantially reduced forest floor cover, plant species composition and prevented the regeneration of many plant species.
Songbirds are also affected by the deer, which browse on the shrubs needed for nesting and cover. The number and variety of birds in a forest are indicators of a healthy ecosystem.
Monitoring activities include the use of permanent vegetation plots to study native and non-native species richness and vegetation cover, the use of deer exclosures to monitor impacts of deer browsing on vegetation, periodic songbird counts and forest cover mapping.