Forest Fires

Forest Fires



Generally, the forest fire season in Canada runs from April through to October. The most fires and the largest areas burned happen in June, July, and August. During a typical fire season there are over 9,000 forest fires in Canada, burning an average of 2.5 million hectares, (25,000 square kilometres).



In Canada, two-thirds of all forest fires are caused by people, while lightning causes the remaining third. This varies across the country: lightning causes over 50% of fires in western Canada and the Northwest Territories. Despite this, lightning fires account for over 85% of the area burned in Canada, largely because many of the lightning-caused fires occur in the West and North, where there are more remote areas that are difficult to reach with fire suppression equipment. Human-caused fires usually start close to communities, where they are reported quickly and dealt with by local fire crews.



Most forest fires are caught in the early stages before they have chance to grow. Under extreme conditions fires can grow rapidly, sometimes exceeding 100,000 ha. In Canada, approximately 2% of forest fires account for 98% of the total area burned.

Pine Beetle



The mountain pine beetle is a species of bark beetle native to the forests of western North America from Mexico to central British Columbia. It has a hard black exoskeleton and measures about 5 millimeters, about the size of a grain of rice.



Mountain pine beetles inhabit spruce. During early stages of an outbreak, attacks are limited largely to trees under stress from injury, poor site conditions, fire damage, overcrowding, root disease, or old age. As beetle populations increase, the beetles attack the largest trees in the outbreak area.



Pine beetles kill trees by boring through the bark into the phloem layer on which they feed and in which eggs are laid. Pioneer female beetles initiate attacks, producing pheromones that attract more beetles. The trees respond to attack by increasing their resin output to discourage or kill the beetles. Pine beetles carry blue stain fungi which, if established, will block the tree resin response. Within about two weeks of a beetle attack, the trees starve to death as the phloem layer is damaged enough to cut off the flow of water and nutrients. Older trees usually succumb first. After particularly hot summers, the mountain pine beetle population can increase dramatically, deforesting large areas. After an outbreak, entire groves of trees will appear red when viewed from above. Rocky Mountain National Park has suffered recent pine beetle outbreaks.



Because of forest fires, pine beetles are drawn to the damaged trees and therefore a large number of spruces have died in western Canada.