Boreal Forest Fires and Carbon Release

The boreal forest, or taiga, forms a nearly continuous band across the high latitudes of Russia, Scandinavia, Canada, and Alaska, and is, by area, the largest terrestrial biome on Earth, covering roughly eleven percent of the planet's land surface. Unlike the mediterranean shrublands that burn almost annually, boreal fire regimes are characterized by long return intervals, typically fifty to two hundred years depending on species composition and regional climate, punctuated by infrequent but extremely intense, stand-replacing crown fires that can consume entire forest stands over enormous areas in a single season. These fires are driven overwhelmingly by lightning in remote interior regions, though human ignition dominates in more accessible or populated areas, and the resulting patchwork of even-aged forest stands, each dating to its last major fire, is a defining structural feature of boreal landscapes from Siberia to the Canadian Shield.