Documents for "Environmental Studies":

• 2,4-D see herbicide.

• acid rain or acid deposition, form of precipitation (rain, snow, sleet, or hail) containing high levels of sulfuric or nitric acids ( p H below 5.5-5.6). Produced when sulfur dioxide and various nitrogen oxides combine with atmospheric moisture, acid rain can contaminate drinking water, damage vegetation and aquatic life, and erode...

• Agent Orange herbicide used by U.S. forces during the Vietnam War to expose enemy guerrilla forces in forested areas. Agent Orange contains varying amounts of dioxin. Exposure to the defoliant has been linked with chemical acne, non-Hodgkin's lymphoma , Hodgkin's disease , and soft-tissue sarcoma. Many soldiers were exposed to Agent Orange in the Vietnam War. Afflicted veterans brought a class-action suit against manufacturers of Agent Orange, which was settled out of court by the...

• air pollution contamination of the air by noxious gases and minute particles of solid and liquid matter (particulates) in concentrations that endanger health. The major sources of air pollution are...

• aldrin see insecticides.

• ANTU see pesticide.

• Audubon Society, National one of the oldest and best-known U.S. environmental organizations; founded 1886 by George Cird Grinnell and named for John James Audubon. The nonprofit organization, which has a membership of 550,000, operates 100 wildlife sanctuaries and nature centers, as well as camps and other educational programs. Current high-priority projects...

• benzene hexachloride see insecticides.

• biochemical oxygen demand see sewerage.

• biocide synonym for pesticide.

• biodiversity see biological diversity.

• biological diversity or biodiversity, the number of species in a given habitat. Scientists have variously estimated that there are from 3 to 30 million extant species, of which 2.5 million have been classified, including 900,000...

• biosphere irregularly shaped envelope of the earth's air, water, and land encompassing the heights and depths at which living things exist. The biosphere is a closed and self-regulating system (see ecology ),...

• Biosphere 2 privately funded ecological research project in which eight people lived sealed in a 3.15-acre (1.28-hectare) structure for two years (Sept. 26, 1991-Sept. 26, 1993). Located in Oracle, Ariz.,...

• bird sanctuary see wildlife refuge.

• BOD see sewerage.

• Bordeaux mixture fungicide consisting of cupric sulfate and lime in water. Its fungicidal activity is associated with the slow formation of copper compounds, the ultimate toxicant being the cupric ion. It originated in France in 1885 and was widely used...

• Burgundy mixture see Bordeaux mixture.

• carbaryl see insecticides.

• cesspool see septic tank.

• chaparral type of plant community in which shrubs are dominant. It occurs usually in regions having from 10 to 20 in. (25-50 cm) of rainfall annually and with a Mediterranean-type climate. Where the rate of...

• chlordane see insecticide.

• chlorinated hydrocarbon insecticide see insecticide.

• climax community see ecology.

• conservation in art: see art conservation and restoration.

• conservation of natural resources the wise use of the earth's resources by humanity. The term conservation came into use in the late 19th cent. and referred to the management, mainly for economic reasons, of such valuable natural resources as timber, fish, game, topsoil, pastureland, and minerals, and...

• conservation of wildlife see conservation of natural resources ; endangered species ; wildlife refuge.

• DDT or 2,2-bis( p -chlorophenyl)-1,1,1,-trichloroethane, chlorinated hydrocarbon compound used as an insecticide. First introduced during the 1940s, it killed insects that spread disease and feed on crops. Swiss scientist Paul Müller was awarded the 1948 Nobel Prize in Physiology or Medicine for discovering...

• defoliant any one of several chemical compounds that, when applied to plants, can alter their metabolism, causing the leaves to drop off. In agriculture defoliants are used to eliminate the leaves of a crop...

• detergent substance that aids in the removal of dirt. Detergents act mainly on the oily films that trap dirt particles. The detergent molecules have a hydrocarbon portion, soluble in oil, and an ionic...

• dieldrin see insecticides.

• Earth Summit see United Nations Conference on Environment and Development.

• ecology study of the relationships of organisms to their physical environment and to one another. The study of an individual organism or a single species is termed autecology; the study of groups of...

• ecosystem see ecology.

• emission rights see pollution allowance.

• endangered species any plant or animal species whose ability to survive and reproduce has been jeopardized by human activities. In 1999 the U.S. government, in accordance with the U.S. Endangered Species Act (1973), classified 935 native...

• endrin see insecticides.

• environmental impact statement analysis of the impact that a proposed development, usually industrial, will have on the natural and social environment. It includes assessment of long- and short-term effects on the physical...

• environmentalism movement to protect the quality and continuity of life through conservation of natural resources , prevention of pollution , and control of land use. The philosophical foundations for environmentalism...

• eutrophication aging of a lake by biological enrichment of its water. In a young lake the water is cold and clear, supporting little life. With time, streams draining into the lake introduce nutrients such as...

• fire, forest see forestry.

• fisheries From earliest times and in practically all countries, fisheries have been of industrial and commercial importance. In the large N Atlantic fishing grounds off Newfoundland and Labrador, for...

• flyway see migration of animals.

• food chain see ecology.

• 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...

• forest fire see forestry.

• fungicide any substance used to destroy fungi. Some fungi are extremely damaging to crops (see diseases of plants ), and others cause diseases in humans and other animals (see fungal infection ). ...

• garbage see solid waste.

• global warming the gradual increase of the temperature of the earth's lower atmosphere as a result of the increase in greenhouse gases since the Industrial Revolution.

• greenhouse effect see global warming.

• Greenpeace international organization that promotes environmental awareness and addresses environmental abuse through direct, nonviolent confrontations with governments and companies. Founded in 1971 to...

• heath tract of open land characterized by a few scattered trees, abundant moss cover, and numerous low shrubs, principally of the heath family (see heath , in botany). In high-latitude regions with minimal variation in climate, the undershrub vegetation may persist indefinitely on shallow, peaty soils rather than undergoing succession to the climax...

• heptachlor see insecticides.

• herbicide chemical compound that kills plants or inhibits their normal growth. A herbicide in a particular formulation and application can be described as selective or nonselective. In agriculture,...

• insecticides chemical, biological, or other agents used to destroy insect pests; the term commonly refers to chemical agents only.

• Integrated Pest Management (IPM), planned program that coordinates economically and environmentally acceptable methods of pest control with the judicious and minimal use of toxic pesticides. IPM programs are based on a...

• International Union for the Conservation of Nature and Natural Resources (IUCN) or World Conservation Union, international organization founded in 1948 to encourage the preservation of wildlife, natural environments, and living resources. Its members include private individuals, nongovernmental...

• jungle [Hindustani jangal =desert, forest; from Skt. jangala =wasteland, uncultivated land], densest form of tropical forest (usually second growth or later) found throughout tropical lowland regions. Jungle is characterized by high humidity and resultant abundance (both in numbers and variety) of flora and concomitantly...

• Kyoto Protocol see global warming.

• land use exploitation of land for agricultural, industrial, residential, recreational, or other purposes. Because the United States historically has a laissez-faire attitude toward land use, the land has...

• lindane see insecticides.

• Malathion see insecticide.

• marine pollution see water pollution.

• marsh see swamp.

• migration of animals movements of animals in large numbers from one place to another. In modern usage the term is usually restricted to regular, periodic movements of populations away from and back to their place of...

• Montreal Protocol officially the Protocol on Substances That Deplete the Ozone Layer, treaty signed on Sept. 16, 1987, at Montreal by 25 nations; 168 nations are now parties to the accord. The protocol set limits on...

• natural resources, conservation of see conservation of natural resources.

• Nature Conservancy nonprofit organization established in 1951 to preserve or aid in the preservation of natural environments. It protects wilderness areas in the United States and Canada and is affiliated with...

• niche see ecology.

• nitrogen cycle the continuous flow of nitrogen through the biosphere by the processes of nitrogen fixation, ammonification (decay), nitrification, and denitrification. Nitrogen is vital to all living matter, both plant and animal; it is an essential constituent of...

• noise pollution human-created noise harmful to health or welfare. Transportation vehicles are the worst offenders, with aircraft, railroad stock, trucks, buses, automobiles, and motorcycles all producing excessive...

• nuclear waste see radioactive waste.

• nuclear winter theory holding that the smoke and dust produced by a large nuclear war would result in a prolonged period of cold on the earth. The earliest version of the theory, which was put forward in the...

• oasis an area within a desert where the water table reaches the surface, with enough moisture to permit the growth of vegetation. The water may come up to the surface in springs, or it may collect in...

• oil spill see water pollution.

• ozone layer or ozonosphere, region of the stratosphere containing relatively high concentrations of ozone , located at altitudes of 12-30 mi (19-48 km) above the earth's surface. Ozone in the ozone layer...

• ozonosphere see ozone layer.

• parathion see insecticide.

• pesticide biological, physical, or chemical agent used to kill plants or animals that are harmful to people; in practice, the term pesticide is often applied only to chemical agents. Various pesticides are...

• pollution contamination of the environment as a result of human activities. The term pollution refers primarily to the fouling of air, water, and land by wastes (see air pollution ; water pollution ; solid waste ). In recent years it has come to signify a wider range of disruptions to environmental quality. Thus litter, billboards, and auto junkyards are said to constitute visual pollution; noise excessive...

• pollution allowance or emission rights, government-issued permit to emit a certain amount of a pollutant. The holder of the permit may use it to pollute legally, may trade permits, or may sell the permit for a profit. The allowance...

• pyrethrin see insecticide.

• radioactive waste material containing the unusable radioactive byproducts of the scientific, military, and industrial applications of nuclear energy. Since its radioactivity presents a serious health hazard (see radiation sickness ), disposing of such material is a great problem. Methods of disposal include dumping concrete-encased containers filled with radioactive waste in the ocean and burying the waste underground in old...

• rain forest see forest.

• recycling the process of recovering and reusing waste products—from household use, manufacturing, agriculture, and business—and thereby reducing their burden on the environment. During World War I and World...

• refuse see solid waste.

• rodenticide see pesticide.

• rotenone see insecticide.

• sanitary landfill see solid waste.

• sanitary science principles of health preservation, embracing hygiene , on an individual level, and public health , on a communal level. Those who specialize in sanitary science are sanitary engineers. They endeavor to eliminate or reduce health hazards associated with the supply of water and milk, the...

• sanitation see plumbing ; sanitary science.

• savanna or savannah , tropical or subtropical grassland lying on the margin of the trade wind belts. The climate of a savanna is characterized by a rainy period during the summer when the area is covered by grasses, and by a dry winter when the grasses wither. Savannas near the equatorial...

• septic tank underground sedimentation tank in which sewage is retained for a short period while it is decomposed and purified by bacterial action. The organic matter in the sewage settles to the bottom of the...

• sevin see insecticides.

• sewerage system for the removal and disposal of chiefly liquid wastes and of rainwater, which are collectively called sewage. The average person in the industrialized world produces between 60 and 140...

• Sierra Club national organization in the United States dedicated to the preservation and expansion of the world's parks, wildlife, and wilderness areas. Founded (1892) in California by a group led by the...

• smog [ sm oke+f og ], dense, visible air pollution. Smog is commonly of two types. The gray smog of older industrial cities like London and New York derives from the massive combustion of coal and fuel oil in or near the city, releasing tons of...

• smoke visible gaseous product of incomplete combustion. Smoke varies with its source, but it usually comprises hot gas and suspended particles of carbon and tarry substances, or soot. To reduce the...

• solid waste discarded materials other than fluids. In the United States in 1996, nearly 210 million tons—about 4.3 lb. (2 kg) per person daily (up from 2.7 lb./1.2 kg in 1960)—were collected and disposed of by...

• spraying horticultural practice of applying fungicides, insecticides, and herbicides, usually in solution, to plants. It may be accomplished by various means, e.g., the watering can, sprinkler attachment,...

• succession see ecology.

• swamp shallow body of water in a low-lying, poorly drained depression, usually containing abundant plant growth dominated by trees, such as cypress, and high shrubs. Swamps develop in moist climates,...

• thermal pollution see water pollution.

• timberline elevation above which trees cannot grow. Its location is influenced by the various factors that determine temperature, including latitude, prevailing wind directions, and exposure to sunlight. In...

• toxaphene see insecticides.

• toxic waste is waste material, often in chemical form, that can cause death or injury to living creatures. It usually is the product of industry or commerce, but comes also from residential use, agriculture,...

• trapping most broadly, the use of mechanical or deceptive devices to capture, kill, or injure animals. It may be applied to the practice of using birdlime to capture birds, lobster pots to trap lobsters,...

• tropics also called tropical zone or torrid zone, all the land and water of the earth situated between the Tropic of Cancer at lat. 23 1/2 °N and the Tropic of Capricorn at lat. 23 1/2 °S. Every point within the tropics receives the perpendicular rays of the sun at noon on at least one day of the year. The sun is directly overhead at lat. 23 1/2 °N on June 21 or 22, the summer solstice, and at lat. 23 1/2 °S on Dec. 21 or 22, the winter solstice. Since the entire tropical zone receives the rays of the sun more directly than areas in higher latitudes, the average annual temperature of the tropics is...

• tundra treeless plains of N North America and N Eurasia, lying principally along the Arctic Circle, on the coasts and islands of the Arctic Ocean, and to the north of the coniferous forest belt. The...

• waste see solid waste.

• water pollution contamination of water resources by harmful wastes; see also sewerage , water supply , pollution , and environmentalism.

• water supply process or activity by which water is provided for some use, e.g., to a home, factory, or business. The term may also refer to the supply of water provided in this way.

• water, desalination of process of removing soluble salts from water to render it suitable for drinking, irrigation, or industrial uses. The principal methods used for desalination include distillation (or evaporation), electrodialysis,...

• weed killer see herbicide.

• wetlands low-lying ecosystem where the water table is always at or near the surface. It is divided into estuarine and freshwater systems, which may be further subdivided by soil type and plant life into bogs , swamps , and marshes. Because wetlands have poor drainage, the area is characterized by sluggish or standing water that can create an open-water habitat for wildlife. Wetlands help to regulate the water...

• whaling the hunting of whales for the oil that can be rendered from their flesh, for meat, and for baleen (whalebone). Historically, whale oil was economically the most important.

• wilderness land retaining its primeval character with the imprint of humans minimal or unnoticeable. In the United States, the Wilderness Act of 1964 established the National Wilderness Preservation System...

• wildlife refuge haven or sanctuary for animals; an area of land or of land and water set aside and maintained, usually by government or private organization, for the preservation and protection of one or more...

• wildlife, conservation of see endangered species ; wildlife refuge ; conservation of natural resources.

• World Conservation Union see International Union for the Conservation of Nature and Natural Resources.

• World Wildlife Fund (WWF), international organization formed to raise money for conservation projects, est. 1961. The international organization, believing that its name no longer reflected the scope of its...

• Worldwide Fund for Nature see World Wildlife Fund.