Boreal forests

Earth’s boreal forests circle our planet’s far northern reaches, just south of the Arctic’s treeless tundra. If the planet wears an Arctic ice cap, then the boreal forests are a loose-knit headband wrapped around its ears, covering large portions of Alaska, Canada, Scandinavia and Siberia. The boreal region’s soils have long buffered the planet against warming by storing huge quantities of carbon and keeping it out of the atmosphere. Its remoteness has historically protected its forests and wetlands from extensive human impact. These two traits rank boreal forests among the most important ecosystems on Earth. In addition, numerous species of mammals, fish, plants, insects and birds make these forests home. For over two centuries, scientists have recognized that climate plays a key role in determining the geographic zones of plant communities. Because boreal forests and soils face subzero winters and short summers, these forests and the animals that li...