Tuktut Nogait National Park, Northwest Territories, Canada

Physical Environment: Precipitation is generally less than 25 cm per year and is often locked up as snow and unavailable for plants. Deeper water can be locked away for a large part of the year in permafrost, a layer of permanently frozen soil. The growing season here is short, only 50–60 days. Summer temperatures are only 3°C–12°C, and even during the long summer days the ground thaws to less than 1 m in depth. Midwinter temperatures average 32°C.  Location: Tundra (from the Finnish tunturia, treeless plain) exists mainly in the northern hemisphere, north of the taiga, because there is very little land area in the southern hemisphere at the latitude where tundra would occur.  Plant Life: With so little available water, trees cannot grow. Vegetation occurs in the form of fragile, slow-growing lichens, mosses, grasses, sedges, and occasional shrubs, which grow close to the ground. Plant diversity is very low. In some places desert conditions prevail because so little moisture falls.  Animal Life: Animals of the arctic tundra have adapted to the cold by having good insulation. Many birds, especially shorebirds and waterfowl, migrate. The fauna is much richer in summer than in winter. Many insects spend the winter at immature stages of growth, which are more resistant to cold than the adult forms. The larger animals include such herbivores as musk oxen and caribou in North America, called reindeer in Europe and Asia, as well as the smaller hares and lemmings. Common predators include arctic fox, wolves, and snowy owls, and polar bears near the coast.  Effects of Humans: Though this area is sparsely populated, mineral extraction, especially of oil, has the potential to significantly impact this biome. Ecosystem recovery from such damage would be very slow.