rain forest: see forest.

forest fire: see forestry.

forest, a dense growth of trees, together with other plants, covering a large area of land. The science concerned with the study, preservation, and management of forests is forestry. A forest is an ecosystem—a community of plants and animals interacting with one another and with the physical environment (see ecology). The forests of the world are classified in three general types, or formations, which are primarily expressions of the climate in which the vegetation grows.

Types of Forests

The tropical hardwood forests, including rain forests, occur throughout the lowland areas of the tropics—especially along the routes of rivers in Central and South America and in central and W Africa—and in the East Indies, the Malay Peninsula, and parts of India, Indochina, and Australia. They are characterized by an annual rainfall of 160-400 in. (406-1,000 cm) annually, with an average temperature of at least 80°F; (27°C;), and support a great diversity of plant life. The foliage is a luxuriant and interlaced community from ground level to the tree canopies, and the trees support the omnipresent woody vines (see liana) and air plants (see epiphyte). Although some tropical forests are deciduous, most tropical trees are considered evergreen because their leaves are not shed simultaneously at a certain season; however, they are believed to drop and renew their leaves sporadically each year. Even though they cover only 7% of the earth's landmass, about one half of the planet's species live there.

The temperate hardwood forests of North America, Europe, and Asia are marked by seasonal rainfall distribution. The trees, typically species of beech, maple, ash, oak, elm, and basswood, are deciduous but are often mixed with conifers, especially in areas of poorer soil. The temperate hardwood forests overlap the boreal, or northern, conifer forest belts, which encircle the earth in the subarctic and cool, temperate regions south of the treeless tundra. The vegetation is typically fir and spruce in northern regions and at higher altitudes, and pine, larch, and hemlock in southern regions and at lower altitudes. In transitional areas, especially where there is a pronounced season without rain (e.g., the chaparral and tropical mountain slopes), scrub forests are frequently found in which the trees are more widely spaced and grasses intervene. Nontropical rain forests exist in New Zealand, Tasmania, Chile, and the Pacific coast of North America.

In the United States east of the prairies are the northern (boreal) forest belt, in which sugar maple, beech, and birch mix with the conifers; the hardwood forest belt, a typical temperate forest; and the warmer southern forest belt, encompassing many stands of smaller pines and cypress thickets. In the chiefly coniferous Rocky Mt. forest belt, the Ponderosa pine is most common. The Pacific forest belt has the heaviest stands of trees in America and probably in the world. The characteristic redwood and giant sequoia mingle with Douglas fir and other species.

Forested Area Today

In early times the only nonforested areas of the earth were those where the land was either excessively dry (e.g., the plains and deserts) or excessively wet (e.g., the swamps). Where the environment was favorable, forests extended from the equator to the timber line, i.e., as far as those regions in the extreme north or at high altitudes where generally there is perpetual snow. Climatic conditions favor the continued expansion of the forests as the ice cap continues to recede and the timber line to withdraw, since the forests, with their mammal and bird inhabitants, move into formerly glaciated regions. However, the favorable natural conditions are more than countered by forest clearing by humans and through fire. About 30% of the world is forested today, but the ratio between forest and population varies immensely. More than one half of the world's softwood timber (the major forest product) comes from North America and Europe—an area with only a fourth of the world's population. Yet the Mediterranean countries have been cleared of most of their forests for centuries, and the forested area of the United States has shrunk in 300 years from about one half to one third of the total land acreage. The United States and Canada share 16% of the world's forests; the former Soviet Union contains 21%, Africa has 20%, and Latin American has 24%.

The Importance of Forests

The chief economic product of forests is timber, but the economic benefits, in terms of climate control, pollution abatement, and wildlife maintenance, have rarely been calculated. The economic importance of nontimber forest products is also increasing. The forest is also vital as a watershed. Because of the thick humus layer, loose soil, and soil-retaining powers of the trees' long roots, forests are vitally important for preserving adequate water supplies. Almost all water ultimately feeds from forest rivers and lakes and from forest-derived water tables. In addition, the forest provides shelter for wildlife, recreation and aesthetic renewal for people, and irreplaceable supplies of oxygen and soil nutrients. Deforestation, particularly in the tropical rain forests, has become a major environmental concern, as it can destabilize the earth's tempeature, humidity, and carbon dioxide levels. Efforts to control deforestation, including those at the 1992 United Nations Conference on Environment and Development, remain ineffective.

fire, forest: see forestry.

Waltham Forest, outer borough (1991 pop. 203,400) of Greater London, SE England. The borough, covering 15 sq mi (40 sq km), is primarily residential. William Morris lived in Water House. The hunting lodge of Queen Elizabeth I is a museum.

Wake Forest University, at Winston-Salem, N.C.; Southern Baptist; coeducational; chartered 1833, opened 1834 at Wake Forest, moved 1956. The school achieved university status in 1967. It has an undergraduate liberal arts college as well as schools of business administration, law, medicine, and graduate studies.

Teutoburg Forest, Ger. Teutoburger Wald, hilly range, in NW Germany, stretching roughly between Osnabrück and Paderborn. It is forested, and it rises to 1,465 ft (447 m) S of Detmold. Near Detmold is a monument (the Hermannsdenkmal ) commemorating the victory (A.D. 9) of the Germans under Arminius (or Hermann, in modern German) over the Roman legions under Varus. The war (late 8th cent.) between Charlemagne and the Saxon Widukind took place in this region.

Sherwood Forest, formerly a large royal forest, mainly in Nottinghamshire, central England. Remnants of the forest exist near Mansfield and Hucknall; efforts began in the 1990s to replant and expand it. It is famous as the haunt of Robin Hood and his band.

River Forest, residential village (1990 pop. 11,669), Cook co., NE Ill., a suburb of Chicago, on the Des Plaines River; inc. 1880. It is the seat of Dominican Univ. and Concordia Univ. Several homes there were designed by Frank Lloyd Wright.

Prince William Forest Park: see National Parks and Monuments (table).

Petrified Forest National Park, 93,533 acres (37,881 hectares), E Ariz.; est. as a national monument 1906, designated a national park 1962. A part of the Painted Desert, it contains the largest known display of petrified wood in the world. There are six separate "forests," with great logs of jasper and agate lying on the ground surrounded by the varied colors of endless fragments and small chips. Dating from the Triassic period, these "stone trees" were killed by natural processes, such as fire, insect attacks, and fungus (or rot). The trees were deeply buried in mud and sand that contained silica-rich volcanic ash. The logs became petrified as the mineral, carried into the wood by groundwater, replaced the wood cells. As the surrounding material was eroded away, the petrified trees were exposed on the surface. Prehistoric Native Americans lived among the stone trees; ruins of their dwellings and their petroglyphs (ancient rock art) remain. Although the first known report of the petrified forests was made by Lt. Lorenzo Sitgreaves, an army officer who explored the area in 1851, they were virtually unknown until the late 1870s. See National Parks and Monuments (table).

Oak Forest, village (1990 pop. 26,203), Cook co., NE Ill., a residential suburb of Chicago; inc. 1947. Oak Forest lies in a grain and livestock area. Industries include the manufacture of chemicals and commercial printing.

New Forest National Park, c.220 sq mi (570 sq km), Hampshire and Wiltshire, S England. Lying mainly in the New Forest dist., SW Hampshire, between the cities of Bournemouth and Southampton, it is roughly bounded by the River Avon, the Solent, Southampton Water, and the River Blackwater. William I organized the area in 1079 as a royal forest to provide revenue and timber. After 1877 the Court of Verderers administered the forest as a public park, and in 2005 the national park was established. The wooded areas contain mostly oak and beech trees as well as extensive tracts of bog and heath. Some 34,000 people live in small towns and villages within the park, and about one fourth of the land in the park is cultivated. Pigs and cattle are raised, and the park is famed for its wild ponies.

National Forest System, federally owned reserves, c.191 million acres (77.4 million hectares), administered by the Forest Service of the U.S. Dept. of Agriculture. The system is made up of 155 national forests and 19 national grasslands in 41 states and Puerto Rico. The majority of reserves are found in the Western states, with Alaska, Idaho, and California having the most extensive holdings. In the East, large national forests are in the Green, White, Allegheny, and Blue Ridge mts. The national grasslands are found on the Great Plains. By law the reserves must be used for timber production, watershed land, wildlife preservation, livestock grazing, mining, and recreation. In 1891, Congress authorized the president to set aside forest reserves; Yellowstone Park Timber Reserve (now Shoshone National Forest) in Wyoming was the first (1891) to be established. The forest reserves were administered by the General Land Office of the Dept. of the Interior until 1905, when they were transferred to the Forest Service by President Teddy Roosevelt. They were designated national forests in 1907. In the late 20th cent., there was increasing pressure from environmental protection groups to change the main emphasis of forest management from the promotion of logging and road-building to the protection of timber reserves. Conflict between environmentalists and business interests over the issue has been heated. Moving to conserve some forest resources, in 1999 the government declared a moratorium on logging and roadbuilding in the undeveloped back country of the national forests. See forest.

Lake Forest, city (1990 pop. 17,836), Lake co., NE Ill., a prestigious residential suburb of Chicago, on Lake Michigan; inc. 1861. The city is known for its scenic lakefront and impressive estates. It is the seat of Lake Forest College, Barat College, and two preparatory schools.

Ironwood Forest National Monument: see National Parks and Monuments (table).

Four Forest Cantons, the, Ger. Die Vier Waldstätten, in central Switzerland, the cantons of Unterwalden, Schwyz, Uri, and Lucerne, the first Swiss communities to win their freedom against the Hapsburgs. In 1291 the three mountain forest cantons (Unterwalden, Schwyz, and Uri) formed the League of Forest Cantons as the nucleus of an independent Switzerland. They were joined by Lucerne in 1332. The Lake of the Four Forest Cantons (Vierwaldstättersee) is called in English the Lake of Lucerne.

Forest Park. 1 City (1990 pop. 16,925), Clayton co., NW Ga., a suburb of Atlanta; inc. 1908. It is a major warehouse and distribution center adjacent to Hartsfield-Jackson Atlanta International Airport and has diverse manufacturing. An army depot and a large state farmers' market are also there. 2 Town (1990 pop. 14,918), Cook co., NE Ill., a suburb of Chicago, on the Des Plaines River; inc. 1884 as Harlem, name changed 1907. Its manufactures include bronze products, burial vaults, and cranes.

Forest Hill, part of metropolitan Toronto, S. Ont., Canada.

Dean, Forest of, ancient royal forest (c.30,000 acres/12,141 hectares), Gloucestershire, W England, between the Severn estuary and the gorges of the Wye River. It was the first (1938) of the National Forest Parks of Great Britain. In the forest are ruins of Roman roads and mines. The forest's economic value lies in its collieries, stone quarries, and timber.

De Forest, Lee, 1873-1961, American inventor, b. Council Bluffs, Iowa, grad. Yale, 1896. He was a pioneer in the development of wireless telegraphy, sound pictures, and television. His triode (1906) made practicable transcontinental telephony, both wire and wireless, and led to the foundation of the radio industry. He is frequently called "the father of radio." The first high-powered naval radio stations were designed and installed by him.

De Forest, John William, 1826-1906, American author, b. Seymour, Conn. He served in the Civil War, chiefly as a captain. His vivid accounts of battle scenes in Louisiana and Sheridan's Shenandoah valley campaign, published in Harper's Monthly, were among the finest contemporaneous war records. Best known as a novelist, he was the author of Kate Beaumont (1872), a study of South Carolina culture, and Miss Ravenel's Conversion from Secession to Loyalty (1876), the first realistic novel of the Civil War.

Brush, George de Forest, 1855-1941, American painter, b. Shelbyville, Tenn., studied in New York City at the National Academy of Design and with Gérôme in Paris. His early, scrupulously realistic paintings of Native Americans gave way, in later work, to Italianate figure compositions. Examples of his work are Mother and Child (Mus. of Fine Arts, Boston) and Mother and Child (Corcoran Gall.).

Brocéliande, Forest of, Ille-et-Vilaine dept., NW France, in Brittany. In Arthurian legend it was the home of Merlin. It is known today as the Forest of Paimpont.

Bohemian Forest, Czech Český Les, Ger. Böhmerwald, mountain range, extending c.150 mi (240 km) along the S Czech-German border and extending into Austria. The Czech name for its southern section is Sumava. A thickly wooded area, it rises to 4,780 ft (1,457 m) in the Grosser Arber (Czech Javor). There are many marshes, swamps, and peat bogs in the Bohemian Forest. Agriculture is limited because of the harsh climate; grazing is common. Coal, graphite, kaolin, and granite are extracted. The region is known for its glassmaking and woodworking.

Black Forest, Ger. Schwarzwald, mountain range, SW Germany, extending 90 mi (145 km) between the Rhine and Neckar rivers. Feldberg is the highest (4,898 ft/1,493 m) peak. The range is covered by dark pine forests and cut by deep valleys and small lakes. The Danube and Neckar rivers rise there. Lumbering and woodworking are important economic activities. Orchards and cattle are found in the valleys; grains are grown in the highlands. The Black Forest is famous for its clock and toy industries (cuckoo clocks, music boxes). It is a year-round resort area, known for its winter sports and mineral springs; Baden-Baden and Freiburg are the chief cities.

Belidor, Bernard Forest de, 1693-1761, French engineer. He wrote numerous books dealing with mathematics, artillery, and hydraulic, civil, and military engineering. One of his engineering works, a manual of rules and tables, was reprinted until 1830. His four-volume Architecture hydraulique (1737-53) was the first work of its kind to apply integral calculus to practical problems; its influence for the next hundred years was international in scope.

Arden, Forest of, well-wooded area, formerly very extensive, in Warwickshire, central England. It is the setting for Shakespeare's As You Like It.

Lush forest, generally composed of tall, broad-leaved trees and usually found in wet tropical regions around the Equator. Despite increased awareness of the rainforests' importance during the late 20th century, they continue to be cleared. Rainforests grow mainly in South and Central America, West and Central Africa, Indonesia, parts of Southeast Asia, and tropical Australia, where the climate is relatively humid with no marked seasonal variation. Depending on the amount of annual rainfall, the trees may be evergreen or mainly deciduous. The former require more water. Temperatures are high, usually about 86 °F (30 °C) during the day and 68 °F (20 °C) at night. Soil conditions vary with location and climate, though most rainforest soils tend to be permanently moist and not very fertile, because the hot, humid weather causes organic matter to decompose rapidly and to be absorbed quickly by tree roots and fungi. Rainforests have several layers. The highest continuous layer, called the canopy, extends across the treetops at a height of 100–165 ft (30–50 m). Most animals live among the leaves and branches. Below the canopy is a thick understory filled with small trees, lianas, and epiphytes. The space directly above the ground can be occupied by tree branches, twigs, and foliage, but, contrary to popular belief, the rainforest floor is not impassable. Rather, it is bare except for a thin layer of humus and fallen leaves. Animals inhabiting this layer (e.g., gorillas, elephants, jaguars, and bears) are adapted to walking or climbing for only short distances. Burrowing animals, such as armadillos and caecilians, are found in the soil, as are microorganisms that help decompose and recycle the organic litter accumulated by other plants and animals from all layers. The climate of the ground layer is unusually stable because the upper stories of tree canopies and the lower branches filter out sunlight, retain heat, and reduce wind speeds, keeping the temperature fairly even.

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In the U.S., any of numerous forest areas under federal supervision for the purposes of conserving water, timber, wildlife, fish, and other renewable resources and providing public recreation areas. Administered by the U.S. Department of Agriculture's Forest Service, in the early 21st century the forests numbered 155 and occupied 352,000 sq mi (911,700 sq km) in 40 states and Puerto Rico. They were founded in 1891 as a system of forest reserves and were renamed national forests in 1907. Seealso Gifford Pinchot.

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Complex ecosystem in which trees are the dominant life-form. Tree-dominated forests can occur wherever the temperatures rise above 50 °F (10 °C) in the warmest months and the annual precipitation is more than 8 in. (200 mm). They can develop under various conditions within these limits, and the kind of soil, plant, and animal life differs according to the extremes of environmental influences. In cool, high-latitude subpolar regions, taiga (boreal) forests are dominated by hardy conifers. In more temperate high-latitude climates, mixed forests of both conifers and broad-leaved deciduous trees predominate. Broad-leaved deciduous forests develop in midlatitude climates. In humid equatorial climates, tropical rainforests develop. There heavy rainfall supports evergreens that have broad leaves instead of the needle leaves of cooler evergreen forests. Having extensive vertical layering, forests are among the most complex ecosystems. Conifer forests have the simplest structure: a tree layer, a shrub layer that is spotty or even absent, and a ground layer covered with lichens, mosses, and liverworts. Deciduous forests are more complex (the tree canopy is divided into an upper and lower story), and rainforest canopies are divided into at least three layers. Forest animals have highly developed hearing, and many are adapted for vertical movement through the environment. Because food other than ground plants is scarce, many ground-dwelling animals use forests only for shelter. The forest is nature's most efficient ecosystem, with a high rate of photosynthesis affecting both plant and animal systems in complex organic relationships.

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Broad-leaved tree that sheds all its leaves during one season. Deciduous forests are found in three middle-latitude regions with a temperate climate characterized by a winter season and year-round precipitation: eastern North America, western Eurasia, and northeastern Asia. They also extend into more arid regions along stream banks and around bodies of water. Oaks, beeches, birches, chestnuts, aspens, elms, maples, and basswoods (or lindens) are the dominant trees in mid-latitude deciduous forests. Other plants that shed their leaves seasonally may also be called deciduous. Seealso conifer, evergreen.

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German Teutoburger Wald

Range of forested hills, northern Germany. It was the scene of a battle in AD 9 in which German tribes defeated the Roman legions, thus establishing the Rhine River as the German-Latin border. The Hermannsdenkmal, a colossal statue commemorating the battle, stands outside Detmold. There are numerous health and holiday resorts in the forest's small hill towns.

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Woodland, Nottinghamshire, England. A former royal hunting ground that is known for its association with the legendary Robin Hood, Sherwood Forest formerly occupied almost all of western Nottinghamshire and extended into Derbyshire. Today a reduced area of woodland remains between Nottingham and Worksop.

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National park, eastern Arizona, U.S. Established as a national monument in 1906 and as a national park in 1962, it has an area of 146 sq mi (378 sq km). It features extensive exhibits of petrified wood in several “forest” areas, fossilized leaves, plants, and broken logs, and the Painted Desert. Other features include petroglyphs and ancient Pueblo Indian ruins.

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(born Aug. 26, 1873, Council Bluffs, Iowa, U.S.—died June 30, 1961, Hollywood, Calif.) U.S. inventor. He had invented many gadgets by age 13, including a working silverplating apparatus. After earning a Ph.D. from Yale University, he founded the De Forest Wireless Telegraph Co. (1902) and the De Forest Radio Telephone Co. (1907). In 1907 he patented the Audion vacuum tube detector, which allowed more sensitive reception of radio signals such as his live broadcast of a performance by Enrico Caruso (1910). He developed a sound-on-film optical-recording system called Phonofilm and demonstrated it in theatres (1923–27). A poor businessman who was twice defrauded by business partners, he eventually sold his patents at low prices to such firms as American Telephone & Telegraph Co., which profited highly from their commercial development. Though embittered, he was widely honoured as the father of radio and the grandfather of television.

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(born Aug. 26, 1873, Council Bluffs, Iowa, U.S.—died June 30, 1961, Hollywood, Calif.) U.S. inventor. He had invented many gadgets by age 13, including a working silverplating apparatus. After earning a Ph.D. from Yale University, he founded the De Forest Wireless Telegraph Co. (1902) and the De Forest Radio Telephone Co. (1907). In 1907 he patented the Audion vacuum tube detector, which allowed more sensitive reception of radio signals such as his live broadcast of a performance by Enrico Caruso (1910). He developed a sound-on-film optical-recording system called Phonofilm and demonstrated it in theatres (1923–27). A poor businessman who was twice defrauded by business partners, he eventually sold his patents at low prices to such firms as American Telephone & Telegraph Co., which profited highly from their commercial development. Though embittered, he was widely honoured as the father of radio and the grandfather of television.

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German Böhmer Wald

Mountain range, central Europe. It lies along the boundary between Bavaria (Germany) and Bohemia (Czech Republic), extending northwest-southeast from the Ohre River to the Danube River valley in Austria. Its highest point, the Arber, rises 4,780 ft (1,457 m). It is the source of the Vltava (Moldau) River.

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German Schwarzwald

Mountain region, Baden-Württemberg, southwestern Germany. It extends in a fairly narrow strip about 100 mi (160 km) along the eastern bank of the upper Rhine River, from the Neckar River to the Swiss border. Its highest peak is Feldberg, at 4,897 ft (1,493 m). Its name comes from its dark interior, the higher parts being thickly forested with fir and pine. It is the source of the Neckar and Danube rivers. The setting of many of the Grimm brothers' fairy tales, it is famed for the beauty and charm of its villages and rolling hills. Winter sports are prominent in the area, which also has many mineral springs and watering places, including the spa town of Baden-Baden.

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(born 1698, Catalonia, Spain—died Sept. 8, 1761, Paris, France) French military and civil engineer. After serving in the French army, he worked on measuring an arc of the Earth. As professor of artillery at a French military school, he wrote notable books on engineering, artillery, ballistics, and fortifications, but his fame rests primarily on his classic Architecture hydraulique (4 vol., 1737–53), covering engineering mechanics, mills and waterwheels, pumps, harbours, and sea works.

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(born 1698, Catalonia, Spain—died Sept. 8, 1761, Paris, France) French military and civil engineer. After serving in the French army, he worked on measuring an arc of the Earth. As professor of artillery at a French military school, he wrote notable books on engineering, artillery, ballistics, and fortifications, but his fame rests primarily on his classic Architecture hydraulique (4 vol., 1737–53), covering engineering mechanics, mills and waterwheels, pumps, harbours, and sea works.

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