developed country
Country that is highly industrialized and has a high per capita GNP. Compare developing country. Formerly called more developed country (MDC).
Subject:
Environmental Science
Forum reference:
Book page:
http://course-notes.org/Environmental_Science
deuterium (D; hydrogen-2)
Isotope of the element hydrogen, with a nucleus containing one proton and one neutron and a mass number of 2.
Subject:
detritus feeder
Organism that extracts nutrients from fragments of dead organisms and their castoff parts and organic wastes. Examples are earthworms, termites, and crabs. Compare decomposer.
Subject:
detritus
Parts of dead organisms and cast-off fragments and wastes of living organisms.
Subject:
Detritivore
Consumer organism that feeds on detritus, parts of dead organisms, and cast-off fragments and wastes of living organisms. The two principal types are detritus feeders and decomposers.
Subject:
Desertification
Conversion of rangeland, rain-fed cropland, or irrigated cropland to desertlike land, with a drop in agricultural productivity of 10% or more. It usually is caused by a combination of overgrazing, soil erosion, prolonged drought, and climate change.
Subject:
Desert
Biome in which evaporation exceeds precipitation and the average amount of precipitation is less than 25 centimeters (10 inches) a year. Such areas have little vegetation or have widely spaced, mostly low vegetation. Compare forest, grassland.
Subject:
desalination
Purification of salt water or brackish (slightly salty) water by removal of dissolved salts.
Subject:
depletion time
Time it takes to use a certain fraction, usually 80%, of the known or estimated supply of a nonrenewable resource at an assumed rate of use. Finding and extracting the remaining 20% usually costs more than it is worth.
Subject:
demographic transition
Hypothesis that countries, as they become industrialized, have declines in death rates followed by declines in birth rates.
Subject:
Pages
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