Is Canada’s managed forest a carbon sink or source?
Throughout most of the past century, Canada’s managed forest has been a strong carbon sink, adding more and more carbon to the amount already stored. This was largely because during the first half of the 20th century, there were periods of relatively few fires and insect outbreaks (compared with the 19th century) in Canada’s forests, allowing them to grow older on average and, in the process, sequester more carbon. In recent decades, the area burned each year by wildfires has doubled, annual harvest rates have increased somewhat, and rates of carbon uptake by aging forests have slowed. These factors have decreased the average annual carbon sink provided by Canada’s managed forest over the past century. Within the managed forest, the area burnt by forest fires varies considerably from year to year. Greenhouse gas emissions from fires can exceed removals of carbon by forest growth and dwarf carbon removals from forest management activities. According to estimates prepared by Natural Reso
