How does disturbance shape Canada's forests?

In 2021, 16.0 million ha of Canada’s forests were affected by insects, a 10% decrease from 2020.

• The areas of moderate-to-severe defoliation by spruce budworm decreased over the entire country. This reduction was seen most strongly in Québec; however, in Ontario and the Northwest Territories, populations increased significantly. Jack pine budworm populations also fell, driven mostly by decreases in Ontario. Populations remained steady in Manitoba.
• The area affected by the spruce beetle decreased slightly, with almost all activity centred in British Columbia and Alberta.
• The unprecedented outbreak of spongy moth continued in Ontario in 2021, with defoliation increasing three-fold to 1.8 million ha, primarily in southern Ontario. Additional defoliation occurred in parts of southern Québec.
• Almost 6 million ha of forest were affected by other insect species. The most significant impacts were seen in the west, with regional outbreaks of species such as large aspen tortrix and two-year cycle spruce budworm.

Why is this indicator important?

• Insects are a normal and natural part of all forest ecosystems and all trees are fed upon by one or more species. Some species of insects, however, may increase their populations to enormous numbers and affect vast areas. These outbreaks are often a normal part of the functioning of forest ecosystems, triggering renewal and change in forest structure. Outbreaks may also reduce Canada’s timber supply, affect carbon stocks, increase the risk of wildfires and reduce the recreational and non-timber uses of forests. Severe insect outbreaks can disrupt the forestry sector, leading to regional or national economic impacts. Therefore, it is important to monitor insect populations to ensure proper management of the effects of outbreaks.
• Invasive insects are an increasing threat to forests in Canada. These species and their negative impacts are most frequently experienced in the southern regions of the country with the highest population density. The effects of invasive insects may be significant but are often difficult to predict because they lack a co-evolved relationship with the trees and ecosystems they infest in Canada. This uncertainty sometimes results in unpredicted events, like the large outbreak of spongy moth seen in southern Ontario in 2020 and 2021. Regulatory controls to limit the establishment or spread of invasive species within Canada, or imposed on Canada by trading partners, can increase production costs, impact timber supply and restrict market access. Understanding the impact of these species and preventing their introduction to Canada will enable Canada to minimize the impacts on fragile ecosystems.

Forest area (in hectares) containing defoliated or beetle-killed trees for key insects in Canada, 2011–2021

Though the total area burned by forest fires in 2022 was below average, two areas of the country experienced unusually active fire seasons: the Maritimes and the western territories.

• A spring fire in Yarmouth County grew to become Nova Scotia’s largest fire on record.
• In Newfoundland, three lightning-caused fires collectively called the Central Fire Complex started in late July near the town of Grand Falls-Windsor. Firefighting crews from five provinces worked into September to bring the fires under control. These were the largest fires in Newfoundland since 1961.
• As was the case in much of the country, spring was cool and wet in the Yukon. But the end of June was hot and dry, and in the first week of July, more than 20,000 lightning strikes ignited 136 fires, keeping crews and fire managers busy with fire suppression, structure protection and highway closures.
• In contrast, the total area burned in Ontario in 2022 was less than 2% of the long-term average.
• The threat of fire to infrastructure was highlighted in July when a wildfire burned the power line to the community of Pukatawagan in northern Manitoba. The entire population of the community, over 2000 people, was evacuated because the fire was burning nearby. Though the threat of the fire receded, they were unable to return home for more than a month because of the power outage. Power was restored with the installation of two 1500-kW diesel generators while Manitoba Hydro worked to replace 77 burned power poles. Repairs to the line were completed in early October.
• Despite extensive protection efforts including high-volume sprinklers and fire-resistant wrapping around power poles, a September fire near Jasper damaged transmission lines and cut off power to the town for two weeks. Everything from campgrounds to gas stations were closed. Tourism Jasper estimated that the town lost $10 million in revenue.
• The fire season continued well into the fall in much of the country. In the western provinces, warm, dry conditions caused significant fire activity to continue into late October. In Québec, there were 33 fires in November, which is normally outside the fire season.
• The total area burned in Canada in 2022 was 1.7 million ha, an area more than twice the size of greater Toronto, or more than five times the size of greater Vancouver.

Why is this indicator important?

• Forest fires can damage or destroy homes and businesses in forested areas, trigger evacuations and disrupt people’s lives and livelihoods.
• Fires produce large amounts of smoke, reducing air quality and visibility.
• An average of $1 billion is spent annually on fire management.
• However, fire plays an important and beneficial role in forest health, succession and nutrient cycling.

Forest area burned and number of forest fires in Canada, 2000–2022

Canada’s forests both absorb carbon and emit atmospheric carbon dioxide, methane, carbon monoxide and nitrous oxide. In any given year, depending on the area of natural disturbances such as forest fires, insect outbreaks and windthrows, Canada’s forests will either be a source of GHGs or a sink of atmospheric carbon. In 2021, the largest area burned since 1990, and managed forests were an overall source of approximately 302.1 Mt CO₂e of GHGs.

In 2021, total net greenhouse gas (GHG) emissions, reported as carbon dioxide equivalent (CO₂e), from Canada’s managed forests (forest lands managed for timber production, conservation or fire suppression) and forest products were approximately 302.1 million tonnes (Mt).

Total net emissions are calculated by adding emissions/removals caused by human activities in Canada’s managed forests to emissions/removals caused by natural disturbances in Canada’s managed forests.

Human activities in Canada’s managed forests accounted for removals of about 8.0 Mt CO₂e from the atmosphere in 2021, while natural disturbances accounted for emissions of about 310.1 Mt CO₂e, resulting in net emissions of about 302.1 Mt CO₂e.

• The area burned in Canada’s managed forests in 2021 was approximately 2.3 million hectares. This was the largest area burned in any year since 1990, about eighteen times the area burned in 2020 and 9% higher than the previous record in 2015. This contributed to the area of Canada’s managed forest affected by natural disturbances emitting about 310 Mt CO₂e.

Why is this indicator important?

• Emissions of carbon dioxide (CO₂), methane (CH₄), carbon monoxide (CO) and nitrous oxide (N₂O) from forest land are important contributors to global warming.
• Canada’s forest sector provides renewable resources to the Canadian economy, resulting in emissions and removals, while also providing employment, aesthetic values, clean water, wildlife habitat and many other ecosystem services.

Net carbon emissions in Canada’s managed forests: All areas, 1990–2021

Net carbon emissions in Canada’s managed forests: Areas subject to human activities, 1990–2021

Net carbon emissions in Canada’s managed forests: Areas subject to natural disturbances, 1990–2021