Life of a Forest
New Forests
New forests regenerate and grow naturally in burned and harvested areas or they can be regenerated artificially through planting or seeding after harvesting.
Immature Forests
Immature forests are generally the healthiest forest and grow at the fastest rate. Saplings and shrubs abound and provide an excellent food source for many animals.
Mature Forests
In the Northwest Territories, mature forests range between 90 and 150 years of age. Although trees may have the potential to grow even older, a high fire frequency generally limits the age to which trees grow. As one moves further north in the Northwest Territories, the average age of trees increases as fire frequency decreases. In many areas of the southern NWT, forests are composed of spruce-aspen mixtures which are less prone to many types of natural disturbance.
Old Forests
As trees age, they become more susceptible to insect damage, tree diseases and climactic stresses. At this stage, trees begin to die, fall over and cover the forest floor. When a forest reaches this stage in succession, the dead standing trees are home to many insects and birds, all the while becoming more prone to intense forest fires.
Forest Disturbance
The Boreal Forest of the Northwest Territories has been shaped by climate, unique soil and landform combinations, and disturbances. The seemingly tranquil state of a forest is actually a vibrant and dynamic state in which the process of succession are continually taking place. The life of a forest involves natural and man-caused disturbances, which remove trees and alter the forest, and the rapid regeneration of young, healthy new forests.
Forest Fires
Fire is the dominant natural disturbance in the boreal forest. Fire has sculpted the forest creating an abundance of habitat for plant and animal life. Forest fires are one of nature's ways of replacing older forests with younger, healthier trees. Some trees, such as the jack pine, lodgepole pine, and even black spruce are adapted to wildfires in that intense heat is required to open most of their cones and release seeds.
Flooding
Whereas forest fire is the dominant natural disturbance in most of the Northwest Territories, flooding is also a major disturbance in the Mackenzie Delta region. During the spring floods of the Mackenzie River with its maze of channels, many trees along the banks of the channel are scoured out and knocked over by debris floating down river. Low lying areas are filled with floodwater, drowning flood-intolerant trees in the process while sedimentation builds up over previously growing plants.
Forest Harvesting
Most of the trees harvested in the Northwest Territories are used to make lumber or for firewood. Generally, trees in burned areas are used for firewood while trees in mature stands are used for lumber and other wood products.
Tree Insects and Disease
Tree insects and diseases are most common in older stands of trees which are not as resilient as young stands of trees. These agents of change help in recycling aging forests. Insects are important in decomposing organic matter. Forests damaged by insects and disease are more susceptible to wind and forest fires.
Wind
The forest soils of the north are typically thin and poorly developed. As a result, many trees, which are shallowly rooted, are susceptible to being blown over during strong winds. In some cases the winds are strong enough to break insect and disease-weakened tree stems, and in other cases will uproot shallowly rooted trees such as white spruce. The result of windthrow and blowdown disturbance is that forest openings are created for regeneration of plants.
Forested Area in the Northwest Territories
There are approximately 33 million hectares of forest land in the Northwest Territories, representing 8% of Canada's entire forested area.This forested area is part of Canada's Boreal Forest Region.