The Boreal Forest: Earth's Green Crown

Photo: Innu Nation / Jay Forsyth

The boreal forest takes on an eerie, fantastical look in its northern fringes as it begins to give way to arctic tundra. The lichen woodlands in this transition zone feature stunted black spruce trees that dot the landscape at intervals of 10 yards or so, sprouting from a deep, spongy mat of lichens, mosses and shrubs. The lichens inhibit tree growth, and provide important winter food for caribou and reindeer.

Another small plant with even greater power to shape a landscape is sphagnum moss. Wherever a spruce-fir forest is cool and moist enough for its liking, this moss will establish a thick carpet on the forest floor. Sphagnum moss can absorb up to 20 times its weight in water, and blocks drainage of moisture from its habitat. As it becomes saturated, the moss carpet takes on the character of a cold, waterlogged sponge. Sphagnum also acidifies its surroundings, and over time only acid-loving plants like black spruce, labrador tea and leatherleaf will remain and thrive in highly acid soil. As the other plants and trees that inhabited the site die out, fall to the forest floor, and are covered over by the growing mosses, they are incorporated into peat, a slowly decaying subsurface layer of dead moss and other organic materials. This is the process by which a tiny moss turns forests into bogs, fens and other peat-filled muskegs -- the Algonquian people's catch-all term for the wetlands of the boreal forest.

Photo: Innu Nation / Jay Forsyth

Canada has more than half a million square miles of muskeg. They are full of unusual landforms and biology, from palsas (hummocks of peat and ice that can rise, mysteriously, up to 25 feet high) to carnivorous plants. Muskegs also provide essential habitat for waterfowl, moose and other wildlife. In addition to these qualities, muskegs are the chief reason why the boreal forest is the world's largest storehouse of organic carbon. In storing so much carbon, the boreal forest keeps heat-trapping carbon dioxide out of the atmosphere. Protecting the boreal forest -- along with reducing emissions from power plants and automobiles -- is crucial to the fight against global warming, more important even than conserving the tropical forests.