Ministry of Environment
Sensitive
Ecosystems Inventories
Older Forest Ecosystems of East Vancouver Island and the Gulf Islands
Older Forest is defined as conifer-dominated forest with an average tree age of 100 years or greater. The trees are generally large and tall, reaching up to 1.5m in diameter and over 50m in height.
Older Forest is often found in combination with Older Second Growth Forest (SG) and occasionally with Terrestrial Herbaceous ecosystems (HT). Based on broad areas of similar climate and vegetation, two biogeoclimatic zones are recognized in this project:
- Coastal Douglas-fir zone (CDF). At lower elevations (<150m), Douglas-fir is the dominant canopy tree in this southern portion of the study area. Low soil moisture conditions favour open stand structure and low growth of herbs, grasses and woody shrubs in the understorey.
- Coastal Western Hemlock zone (CWH). At higher elevations, western hemlock is the dominant tree species in this northern portion of the study area. The forest floor is composed of a dense litter of needles and small branches. Cool, damp and acidic conditions favour a moss layer build up over time.
With greatest representation in the southern coastal lowlands, Older Forests comprise only 2.6% of the entire SEI study area, and 33% of the total area sensitive ecosystems.
Values and Ecological Attributes of Older Forests
As a structurally diverse ecosystem, Older Forests support a rich community of wildlife, plant and invertebrate species which were once common to the landscape. They also serve as specialized habitats for species groups and often depend on specific habitat conditions.
In terms of economic value, Older Forests provide a broad range of marketable forest products and can provide sustainable forestry employment through the use of alternative harvesting and silviculture techniques.
Influenced by disturbance and succession, Older Forests are dynamic ecosystems that change over time. Thus, they provide valuable research and education resources for studies on second growth forest management, coastal forest biodiversity, and silviculture genetics.
Conservation Concerns of Older Forests
Because of their vast natural resource value, Older Forest ecosystems are subject to direct impacts and indirect impacts from: urban developers for the land; recreational users for the wilderness experience; agriculture industry for the livestock grazing vegetation; and resource industry for the timber. In addition, older forest ecosystems are vulnerable to cumulative impacts such as climate changes which benefit pest species, or reduce the suitability of some tree species for our climate.
As a result of these pressures, the conservation of remnant Older Forest in the SEI study area focuses on preventing further fragmentation, ecosystem loss and incremental degradation of older forest ecosystems.
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