taiga Encyclopedic Entry boreal forest

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1 This website would like to remind you: Your browser (Apple Safari 7) is out of date. Update your browser for more security, comfort and the best experience on this site. Encyclopedic Entry taiga boreal forest For the complete encyclopedic entry with media resources, visit: The taiga is a forest of the cold, subarctic region. The subarctic is an area of the Northern Hemisphere that lies just south of the Arctic Circle. The taiga lies between the tundra to the north and temperate forests to the south. Alaska, Canada, Scandinavia, and Siberia have taigas. In Russia, the world s largest taiga stretches about 5,800 kilometers (3,600 miles), from the Pacific Ocean to the Ural Mountains. This taiga region was completely glaciated, or covered by glaciers, during the last ice age. The soil beneath the taiga often contains permafrost a layer of permanently frozen soil. In other areas, a layer of bedrock lies just beneath the soil. Both permafrost and rock prevent water from draining from the top layers of soil. This creates shallow bogs known as muskegs. Muskegs can look like solid ground, because they are covered with moss, short grasses, and sometimes even trees. However, the ground is actually wet and spongy. Plants and Fungi Taigas are thick forests. Coniferous trees, such as spruce, pine, and fir, are common. Coniferous trees have needles instead of broad leaves, and their seeds grow inside protective, woody cones. While deciduous trees of temperate forests lose their leaves in winter, conifers never lose their needles. For this reason, conifers are also called evergreens. Conifers have adapted to survive the long, cold winters and short summers of the 1 of 7

2 taiga. Their needles contain very little sap, which helps prevent freezing. Their dark color and triangle-shaped sides help them catch and absorb as much of the sun s light as possible. In the taiga, tree growth is thickest beside muskegs and lakes formed by glaciers. Taigas have few native plants besides conifers. The soil of the taiga has few nutrients. It can also freeze, making it difficult for many plants to take root. The larch is one of the only deciduous trees able to survive in the freezing northern taiga. Instead of shrubs and flowers, mosses, lichens, and mushrooms cover the floor of a taiga. These organisms can grow directly on the ground, or have very shallow roots. They can survive in the cold, and with little water or sunlight. Animals of the Taiga Many kinds of animals live in the taiga. All animals have to be well-adapted to the cold. Birds native to the taiga usually migrate south during the freezing winter months. Small animals, mostly rodents, live close to the floor. Many birds of prey, such as owls and eagles, hunt these animals from the trees of the taiga. Moose, the largest type of deer in the world, is able to live in the cold taiga. Like all deer, moose are herbivores. They favor the aquatic plants growing on the taiga s bogs and streams. Few large carnivorous animals live in the taiga. Bears and lynx are fairly common. The largest cat in the world, the 300-kilogram (660-pound) Siberian tiger, is a native taiga species. Siberian tigers live in a small part of eastern Siberia. They hunt moose and wild boars. Threats to Taigas Taiga ecosystems are threatened by direct human activity and climate change. Animals of the taiga, such as foxes or bears, have always been hunted. Their warm fur and tough skin, turned into leather, have helped people survive in harsh climates for thousands of years. 2 of 7

3 The most serious threat to taigas does not come from hunting activity, however. Civilization is dependent on sturdy buildings for homes, industry, and schools. The trees of the taiga are cut down for lumber projects, as well as paper, cardboard, and other supplies. The export of wood and paper products is one of the most economically important industries in Canada, for instance. Clearcutting is the most popular type of logging in taigas. Clearcutting involves cutting down all the trees in a designated area. This destroys habitats for many organisms that live in and around the trees, and makes it difficult for new trees to grow. Clearcutting also increases the risk of erosion and flooding in the taiga. Without a root system to anchor it, a taiga s soil can be blown away by wind or worn away by rain or snow. This exposes the bedrock and permafrost beneath the taiga, which does not support many forms of life. Climate change puts taigas in danger in different ways. Warming climate contributes to a partial thawing of the permafrost. Since this water has no place to drain, more area of the taiga is taken over by muskegs. Few trees take root. Warming temperature also changes animal habitats. It pushes native species out and attracts non-native species. Animals such as the Siberian tiger are not adapted to warm weather. Its coat is too heavy, and it stores too much body fat to thrive in a temperate habitat. Non-native insects such as the bark beetle can infest trees such as spruce. Millions of these insects bore into the bark of trees, laying eggs. The infested trees die. Bark beetle infestations can kill entire forests and thousands of hectares of taiga. Vocabulary Term absorb verb to soak up. acre unit of measure equal to.4 hectares. adapt verb to adjust to new surroundings or a new situation. anchor verb to hold firmly in place. 3 of 7

4 animal organisms that have a well-defined shape and limited growth, can move voluntarily, acquire food and digest it internally, and can respond rapidly to stimuli. aquatic adjectivehaving to do with water. Arctic paralell of latitude that runs 66.5 degrees north of the Circle Equator. bark typically hard, outer covering of a tree. bark beetle insect that nests in hardwood trees. bear mammal with a very large body, relatively short limbs, and an elongated snout. bedrock solid rock beneath the Earth's soil and sand. bird egg-laying animal with feathers, wings, and a beak. boar mammal, related to a pig, native to Europe and Asia. bog wetland of soft ground made mostly of decaying plant matter. bore verb to drill or tunnel into something. boreal land covered by evergreen trees in cool, northern latitudes. forest Also called taiga. broad adjectivewide or expansive. cardboard thick, stiff paper made of wood pulp. carnivorous adjectivemeat-eating. civilization complex way of life that developed as humans began to develop urban settlements. clearcutting process of cutting down all the vegetation in an area, usually as part of an economic industry. climate all weather conditions for a given location over a period of time. climate gradual changes in all the interconnected weather elements change on our planet. conifer plant that produces seeds in hard cones, such as pine. Also called a coniferous tree. deciduous adjectivetype of plant that sheds its leaves once a year. deer mammal whose male members have antlers. designate verb to name or single out. 4 of 7

5 eagle large, powerful bird of prey. community and interactions of living and nonliving things in ecosystem an area. erosion act in which earth is worn away, often by water, wind, or ice. evergreen tree that does not lose its leaves. export good or service traded to another area. expose verb to uncover. fat material found in organisms that is colorless and odorless and may be solid or liquid at room temperature. fir variety of pine tree. flood overflow of a body of water onto land. flower blossom or reproductive organs of a plant. forest ecosystem filled with trees and underbrush. fox type of mammal related to a dog with a thin muzzle and thick tail. fringe verb to exist on the border or edge. fur thick hair covering the skin of an animal. glacial process by which glaciers melt faster than precipitation can retreat replace the ice. glacier mass of ice that moves slowly over land. grass type of plant with narrow leaves. herbivore organism that eats mainly plants. home an organism's native place; could be a residence, a town or a country. hunt verb to pursue and kill an animal, usually for food. ice age long period of cold climate where glaciers cover large parts of the Earth. The last ice age peaked about 20,000 years ago. Also called glacial age. industry activity that produces goods and services. infest verb to invade, overrun, and take over. insect type of animal that breathes air and has a body divided into three segments, with six legs and usually wings. larch deciduous, coniferous tree. leaf organ growing from the stem of a plant. 5 of 7

6 leather skin of an animal, prepared for use as clothing, protection, shelter, or other use. lichen logging organism composed of a fungus or fungi and an alga or cyanobacterium. industry engaged in cutting down trees and moving the wood to sawmills. lumber precisely cut pieces of wood such as boards or planks. lynx large cat native to Norh America. migrate verb to move from one place or activity to another. moss tiny plant usually found in moist, shady areas. mushroom fungus, usually with an umbrella-shaped cap on top of a slender stalk. muskeg bog, especially one in North America. native species species that occur naturally in an area or habitat. Also called indigenous species. needle long, thin, pointed leaf. non-native species Northern Hemisphere a type of plant or animal that is not indigenous to a particular area. Non-native species can sometimes cause economic or environmental harm as an invasive species. half of the Earth between the North Pole and the Equator. nutrient substance an organism needs for energy, growth, and life. owl bird of prey. partial permafrost adjectiveincomplete. permanently frozen layer of the Earth's surface. pine type of evergreen tree with needle-shaped leaves. plant organism that produces its own food through photosynthesis and whose cells have walls. prey animal that is hunted and eaten by other animals. rock natural substance composed of solid mineral matter. rodent root order of mammals often characterized by long teeth for gnawing and nibbling. part of a plant that secures it in the soil, obtains water and nutrients, and often stores food made by leaves. 6 of 7

7 root system all of a plant's roots. sap fluid that distributes nutrients throughout a plant. Scandinavia region and name for some countries in Northern Europe: Iceland, Norway, Sweden, Finland, and Denmark. seed part of a plant from which a new plant grows. shrub type of plant, smaller than a tree but having woody branches. Siberia region of land stretching across Russia from the Ural Mountains to the Pacific Ocean. Siberian tiger endangered species native to far eastern Siberia. soil top layer of the Earth's surface where plants can grow. spruce coniferous, or cone-bearing, tree. stream body of flowing water. subarctic region just south of the Arctic Circle. survive verb to live. taiga evergreen forest in cool, northern latitudes. Also called boreal forest. temperate adjectivemoderate. thaw verb to melt, or turn from ice to liquid. thrive verb to develop and be successful. tree type of large plant with a thick trunk and branches. tundra cold, treeless region in Arctic and Antarctic climates. Articles & Profiles World Wildlife Fund: East Siberian Taiga Websites NASA: BOREAS The Boreal Ecosystem Atmosphere Study National Geographic Society. All rights reserved. 7 of 7