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Environmental Science: A Global Concern, 7/e
William P. Cunningham, University of Minnesota
Mary Ann Cunningham, Vassar College
Barbara Woodworth Saigo, St. Cloud State University

Glossary A-D

abundance  The number or amount of something.
acid precipitation  Acidic rain, snow, or dry particles deposited from the air due to increased acids released by anthropogenic or natural resources.
acids  Substances that release hydrogen ions (protons) in water.
active solar system  A mechanical system that actively collects, concentrates, and stores solar energy.
acute poverty  Insufficient income or access to resources needed to provide the basic necessities for life such as food, shelter, sanitation, clean water, medical care, and education.
adaptive management  A management plan designed from the outset to "learn by doing," and to actively test hypotheses and adjust treatments as new information becomes available.
administrative courts  Courts that hear enforcement cases for agencies or consider appeals to agency rules.
administrative law  Executive orders, administrative rules and regulations, and enforcement decisions by administrative agencies and special administrative courts.
aerobic  Living or occurring only in the presence of oxygen.
aerosols  Minute particles or liquid droplets suspended in the air.
aesthetic degradation  Changes in environmental quality that offend our aesthetic senses.
albedo  A description of a surface's reflective properties.
ambient air  The air immediately around us.
amino acid  An organic compound containing an amino group and a carboxyl group; amino acids are the units or building blocks that make peptide and protein molecules.
anaerobic respiration  The incomplete intracellular breakdown of sugar or other organic compounds in the absence of oxygen that releases some energy and produces organic acids and/or alcohol.
anemia  Low levels of hemoglobin due to iron deficiency or lack of red blood cells.
annual  A plant that lives for a single growing season.
anthropocentric  The belief that humans hold a special place in nature; being centered primarily on humans and human affairs.
appropriate technology  Technology that can be made at an affordable price by ordinary people using local materials to do useful work in ways that do the least possible harm to both human society and the environment.
aquifers  Porous, water-bearing layers of sand, gravel, and rock below the earth's surface; reservoirs for groundwater.
arbitration  A formal process of dispute resolution in which there are stringent rules of evidence, cross-examination of witnesses, and a legally binding decision made by the arbitrator that all parties must obey.
arithmetic growth  A pattern of growth that increases at a constant amount per unit time, such as 1, 2, 3, 4 or 1, 3, 5, 7.
artesian well  The result of a pressurized aquifer intersecting the surface or being penetrated by a pipe or conduit, from which water gushes without being pumped; also called a spring.
asthma  A distressing disease characterized by shortness of breath, wheezing, and bronchial muscle spasms.
atmospheric deposition  Sedimentation of solids, liquids, or gaseous materials from the air.
atom  The smallest unit of matter that has the characteristics of an element; consists of three main types of subatomic particles: protons, neutrons, and electrons.
atomic number  The characteristic number of protons per atom of an element. Used as an identifying attribute.
autotroph  An organism that synthesizes food molecules from inorganic molecules by using an external energy source, such as light energy.
barrier islands  Low, narrow, sandy islands that form offshore from a coastline.
bases  Substances that bond readily with hydrogen ions.
BAT  See best available, economically achievable technology.
Batesian mimicry  Evolution by one species to resemble the coloration, body shape, or behavior of another species that is protected from predators by a venomous stinger, bad taste, or some other defensive adaptation.
benthos  The bottom of a sea or lake.
best available, economically achievable technology (BAT)  The best pollution control available.
best practical control technology (BPT)  The best technology for pollution control available at reasonable cost and operable under normal conditions.
beta particles  High-energy electrons released by radioactive decay.
bill  A piece of legislation introduced in Congress and intended to become law.
bioaccumulation  The selective absorption and concentration of molecules by cells.
biocentric preservation  A philosophy that emphasizes the fundamental right of living organisms to exist and to pursue their own goods.
biocentrism  The belief that all creatures have rights and values; being centered on nature rather than humans.
biocide  A broad-spectrum poison that kills a wide range of organisms.
biodegradable plastics  Plastics that can be decomposed by microorganisms.
biodiversity  The genetic, species, and ecological diversity of the organisms in a given area.
biogeochemical cycles  Movement of matter within or between ecosystems; caused by living organisms, geological forces, or chemical reactions. The cycling of nitrogen, carbon, sulfur, oxygen, phosphorus, and water are examples.
biogeographical area  An entire self-contained natural ecosystem and its associated land, water, air, and wildlife resources.
biological community  The populations of plants, animals, and microorganisms living and interacting in a certain area at a given time.
biological controls  Use of natural predators, pathogens, or competitors to regulate pest populations.
biological or biotic factors  Organisms and products of organisms that are part of the environment and potentially affect the life of other organisms.
biological oxygen demand (BOD)  A standard test for measuring the amount of dissolved oxygen utilized by aquatic microorganisms.
biological pests  Organisms that reduce the availability, quality, or value of resources useful to humans.
biological resources  The earth's organisms.
biomagnification  Increase in concentration of certain stable chemicals (for example, heavy metals or fat-soluble pesticides) in successively higher trophic levels of a food chain or web.
biomass  The total mass or weight of all the living organisms in a given population or area.
biomass fuel  Organic material produced by plants, animals, or microorganisms that can be burned directly as a heat source or converted into a gaseous or liquid fuel.
biomass pyramid  A metaphor or diagram that explains the relationship between the amounts of biomass at different trophic levels.
biome  A broad, regional type of ecosystem characterized by distinctive climate and soil conditions and a distinctive kind of biological community adapted to those conditions.
bioremediation  Use of biological organisms to remove or detoxify pollutants from a contaminated area.
biosphere  The zone of air, land, and water at the surface of the earth that is occupied by organisms.
biosphere reserves  World heritage sites identified by the IUCN as worthy for national park or wildlife refuge status because of high biological diversity or unique ecological features.
biota  All organisms in a given area.
biotic  Pertaining to life; environmental factors created by living organisms.
biotic potential  The maximum reproductive rate of an organism, given unlimited resources and ideal environmental conditions. Compare with environmental resistance.
birth control  Any method used to reduce births, including celibacy, delayed marriage, contraception; devices or medication that prevent implantation of fertilized zygotes, and induced abortions.
black lung disease  Inflammation and fibrosis caused by accumulation of coal dust in the lungs or airways. See respiratory fibrotic agents.
blue revolution  New techniques of fish farming that may contribute as much to human nutrition as miracle cereal grains but also may create social and environmental problems.
bog  An area of waterlogged soil that tends to be peaty; fed mainly by precipitation; low productivity; some bogs are acidic.
boreal forest  A broad band of mixed coniferous and deciduous trees that stretches across northern North America (and also Europe and Asia); its northernmost edge, the taiga, intergrades with the arctic tundra.
BPT  See best practical control technology.
breeder reactor  A nuclear reactor that produces fuel by bombarding isotopes of uranium and thorium with high-energy neutrons that convert inert atoms to fissionable ones.
brownfields  Abandoned or underused urban areas in which redevelopment is blocked by liability or financing issues related to toxic contamination.
cancer  Invasive, out-of-control cell growth that results in malignant tumors.
capital  Any form of wealth, resources, or knowledge available for use in the production of more wealth.
captive breeding  Raising plants or animals in zoos or other controlled conditions to produce stock for subsequent release into the wild.
carbohydrate  An organic compound consisting of a ring or chain of carbon atoms with hydrogen and oxygen attached; examples are sugars, starches, cellulose, and glycogen.
carbon cycle  The circulation and reutilization of carbon atoms, especially via the processes of photosynthesis and respiration.
carbon management  Storing CO2 or using it in ways that prevent its release into the air.
carbon monoxide (CO)  Colorless, odorless, nonirritating but highly toxic gas produced by incomplete combustion of fuel, incineration of biomass or solid waste, or partially anaerobic decomposition of organic material.
carbon sink  Places of carbon accumulation, such as in large forests (organic compounds) or ocean sediments (calcium carbonate); carbon is thus removed from the carbon cycle for moderately long to very long periods of time.
carbon source  Originating point of carbon that reenters the carbon cycle; cellular respiration and combustion.
carcinogens  Substances that cause cancer.
carnivores  Organisms that mainly prey upon animals.
carrying capacity  The maximum number of individuals of any species that can be supported by a particular ecosystem on a long-term basis.
case law  Precedents from both civil and criminal court cases.
cash crops  Crops that are sold rather than consumed or bartered.
catastrophic systems  Dynamic systems that jump abruptly from one seemingly steady state to another without any intermediate stages.
cell  Minute biological compartments within which the processes of life are carried out.
cellular respiration  The process in which a cell breaks down sugar or other organic compounds to release energy used for cellular work; may be anaerobic or aerobic, depending on the availability of oxygen.
chain reaction  A self-sustaining reaction in which the fission of nuclei produces subatomic particles that cause the fission of other nuclei.
chaotic systems  Systems that exhibit variability, which may not be necessarily random, yet whose complex patterns are not discernible over a normal human time scale.
chemical bond  The force that holds atoms together in molecules and compounds.
chemical energy  Potential energy stored in chemical bonds of molecules.
chlorofluorocarbons  Chemical compounds with a carbon skeleton and one or more attached chlorine and fluorine atoms. Commonly used as refrigerants, solvents, fire retardants, and blowing agents.
chloroplasts  Chlorophyll-containing organelles in eukaryotic organisms; sites of photosynthesis.
chronic effects  Long-lasting results of exposure to a toxin; can be a permanent change caused by a single, acute exposure or a continuous, low-level exposure.
chronic food shortages  Long-term undernutrition and malnutrition; usually caused by people's lack of money to buy food or lack of opportunity to grow it themselves.
citizen science  Projects in which trained volunteers work with scientific researchers to answer real-world questions.
city  A differentiated community with a sufficient population and resource base to allow residents to specialize in arts, crafts, services, and professional occupations.
civil law  A body of laws regulating relations between individuals or between individuals and corporations concerning property rights, personal dignity and freedom, and personal injury.
classical economics  Modern, western economic theories of the effects of resource scarcity, monetary policy, and competition on supply and demand of goods and services in the marketplace. This is the basis for the capitalist market system.
clear-cut  Cutting every tree in a given area, regardless of species or size; an appropriate harvest method for some species; can be destructive if not carefully controlled.
climate  A description of the long-term pattern of weather in a particular area.
climax community  A relatively stable, long-lasting community reached in a successional series; usually determined by climate and soil type.
closed canopy  A forest where tree crowns spread over 20 percent of the ground; has the potential for commercial timber harvests.
cloud forests  High mountain forests where temperatures are uniformly cool and fog or mist keeps vegetation wet all the time.
coal gasification  The heating and partial combustion of coal to release volatile gases, such as methane and carbon monoxide; after pollutants are washed out, these gases become efficient, clean-burning fuel.
coal washing  Coal technology that involves crushing coal and washing out soluble sulfur compounds with water or other solvents.
Coastal Zone Management Act  Legislation of 1972 that gave federal money to 30 seacoast and Great Lakes states for development and restoration projects.
co-composting  Microbial decomposition of organic materials in solid waste into useful soil additives and fertilizer; often, extra organic material in the form of sewer sludge, animal manure, leaves, and grass clippings are added to solid waste to speed the process and make the product more useful.
coevolution  The process in which species exert selective pressure on each other and gradually evolve new features or behaviors as a result of those pressures.
cogeneration  The simultaneous production of electricity and steam or hot water in the same plant.
cold front  A moving boundary of cooler air displacing warmer air.
coliform bacteria  Bacteria that live in the intestines (including the colon) of humans and other animals; used as a measure of the presence of feces in water or soil.
commensalism  A symbiotic relationship in which one member is benefited and the second is neither harmed nor benefited.
common law  The body of court decisions that constitute a working definition of individual rights and responsibilities where no formal statutes define these issues.
communal resource management systems  Resources managed by a community for long-term sustainability.
competitive exclusion  A theory that no two populations of different species will occupy the same niche and compete for exactly the same resources in the same habitat for very long.
complexity (ecological)  The number of species at each trophic level and the number of trophic levels in a community.
composting  The biological degradation of organic material under aerobic (oxygen-rich) conditions to produce compost, a nutrient-rich soil amendment and conditioner.
compound  A molecule made up of two or more kinds of atoms held together by chemical bonds.
condensation  The aggregation of water molecules from vapor to liquid or solid when the saturation concentration is exceeded.
condensation nuclei  Tiny particles that float in the air and facilitate the condensation process.
conifers  Needle-bearing trees that produce seeds in cones.
conservation development  Consideration of landscape history, human culture, topography, and ecological values in subdivision design. Using cluster housing, zoning, covenants, and other design features, at least half of a subdivision can be preserved as open space, farmland, or natural areas.
conservation of matter  In any chemical reaction, matter changes form; it is neither created nor destroyed.
conspicuous consumption  A term coined by economist and social critic Thorstein Veblen to describe buying things we don't want or need to impress others.
consumer  An organism that obtains energy and nutrients by feeding on other organisms or their remains. See also heterotroph.
consumption  The fraction of withdrawn water that is lost in transmission or that is evaporated, absorbed, chemically transformed, or otherwise made unavailable for other purposes as a result of human use.
contour plowing  Plowing along hill contours; reduces erosion.
control rods  Neutron-absorbing material inserted into spaces between fuel assemblies in nuclear reactors to regulate fission reaction.
convection currents  Rising or sinking air currents that stir the atmosphere and transport heat from one area to another. Convection currents also occur in water; see spring overturn.
cool deserts  Deserts such as the American Great Basin characterized by cold winters and sagebrush.
coral reefs  Prominent oceanic features composed of hard, limy skeletons produced by coral animals; usually formed along edges of shallow, submerged ocean banks or along shelves in warm, shallow, tropical seas.
core  The dense, intensely hot mass of molten metal, mostly iron and nickel, thousands of kilometers in diameter at the earth's center.
core region  The primary industrial region of a country; usually located around the capital or largest port; has both the greatest population density and the greatest economic activity of the country.
Coriolis effect  The influence of friction and drag on air layers near the earth; deflects air currents to the direction of the earth's rotation.
cornucopian fallacy  The belief that nature is limitless in its abundance and that perpetual growth is not only possible but essential.
corridor  A strip of natural habitat that connects two adjacent nature preserves to allow migration of organisms from one place to another.
cost-benefit analysis  An evaluation of large-scale public projects by comparing the costs and benefits that accrue from them.
cover crops  Plants, such as rye, alfalfa, or clover, that can be planted immediately after harvest to hold and protect the soil.
criminal law  A body of court decisions based on federal and state statutes concerning wrongs against persons or society.
criteria pollutants  See conventional pollutants.
critical factor  The single environmental factor closest to a tolerance limit for a given species at a given time. See limiting factors.
critical thinking  An ability to evaluate information and opinions in a systematic, purposeful, efficient manner.
croplands  Lands used to grow crops.
crude birth rate  The number of births in a year divided by the midyear population.
crude death rate  The number of deaths per thousand persons in a given year; also called crude mortality rate.
crust  The cool, lightweight, outermost layer of the earth's surface that floats on the soft, pliable underlying layers; similar to the "skin" on a bowl of warm pudding.
cultural eutrophication  An increase in biological productivity and ecosystem succession caused by human activities.
debt-for-nature swap  Forgiveness of international debt in exchange for nature protection in developing countries.
deciduous  Trees and shrubs that shed their leaves at the end of the growing season.
decline spiral  A catastrophic deterioration of a species, community, or whole ecosystem; accelerates as functions are disrupted or lost in a downward cascade.
decomposers  Fungi and bacteria that break complex organic material into smaller molecules.
deductive reasoning  Deriving testable predictions about specific cases from general principles.
deep ecology  A philosophy that calls for a profound shift in our attitudes and behavior based on voluntary simplicity; rejection of anthropocentric attitudes; intimate contact with nature; decentralization of power; support for cultural and biological diversity; a belief in the sacredness of nature; and direct personal action to protect nature, improve the environment, and bring about fundamental societal change.
degradation (of water resource)  Deterioration in water quality due to contamination or pollution; makes water unsuitable for other desirable purposes.
Delaney Clause  A controversial amendment to the Federal Food, Drug, and Cosmetic Act, added in 1958, prohibiting the addition of any known cancer-causing agent to processed foods, drugs, or cosmetics.
delta  Fan-shaped sediment deposit found at the mouth of a river.
demand  The amount of a product that consumers are willing and able to buy at various possible prices, assuming they are free to express their preferences.
demanufacturing  Disassembly of products so components can be reused or recycled.
demographic transition  A pattern of falling death rates and birthrates in response to improved living conditions; could be reversed in deteriorating conditions.
demography  Vital statistics about people: births, marriages, deaths, etc.; the statistical study of human populations relating to growth rate, age structure, geographic distribution, etc., and their effects on social, economic, and environmental conditions.
denitrifying bacteria  Free-living soil bacteria that converts nitrates to gaseous nitrogen and nitrous oxide.
dependency ratio  The number of nonworking members compared to working members for a given population.
desalinization (or desalination)  Removal of salt from water by distillation, freezing, or ultrafiltration.
desert  A type of biome characterized by low moisture levels and infrequent and unpredictable precipitation. Daily and seasonal temperatures fluctuate widely.
desertification  Denuding and degrading a once-fertile land, initiating a desert-producing cycle that feeds on itself and causes long-term changes in soil, climate, and biota of an area.
detritivore  Organisms that consume organic litter, debris, and dung.
dew point  The temperature at which condensation occurs for a given concentration of water vapor in the air.
dieback  A sudden population decline; also called a population crash.
diminishing returns  A condition in which unrestrained population growth causes the standard of living to decrease to a subsistence level where poverty, misery, vice, and starvation makes life permanently drab and miserable. This dreary prophecy has led economics to be called "the dismal science."
direct action  Civil disobedience, guerrilla street theater, picketing, protest marches, road blockades, demonstrations, and other techniques borrowed from the civil rights movement and applied to environmental protection.
disability-adjusted life years (DALY)  A measure of premature deaths and losses due to illnesses and disabilities in a population.
discharge  The amount of water that passes a fixed point in a given amount of time; usually expressed as liters or cubic feet of water per second.
disease  A deleterious change in the body's condition in response to destabilizing factors, such as nutrition, chemicals, or biological agents.
dissolved oxygen (DO) content  Amount of oxygen dissolved in a given volume of water at a given temperature and atmospheric pressure; usually expressed in parts per million (ppm).
diversity (species diversity, biological diversity)  The number of species present in a community (species richness), as well as the relative abundance of each species.
DNA  Deoxyribonucleic acid; the long, double-helix molecule in the nucleus of cells that contains the genetic code and directs the development and functioning of all cells.
dominant plants  Those plant species in a community that provide a food base for most of the community; they usually take up the most space and have the largest biomass.
downbursts  Sudden, very strong, downdrafts of cold air associated with an advancing storm front.
drip irrigation  Uses pipe or tubing perforated with very small holes to deliver water one drop at a time directly to the soil around each plant.
dry alkali injection  Spraying dry sodium bicarbonate into flue gas to absorb and neutralize acidic sulfur compounds.