Botkin Environmental Science Earth as Living Planet 8th txtbk

G-2 Glossary
or neutrons in the nucleus of an isotope spontaneously
changes.
Biochemical oxygen demand (BOD) A measure of the
amount of oxygen necessary to decompose organic material
in a unit volume of water. As the amount of organic
waste in water increases, more oxygen is used, resulting in
a higher BOD.
Biogeochemical cycle The cycling of a chemical element
through the biosphere; its pathways, storage locations, and
chemical forms in living things, the atmosphere, oceans,
sediments, and lithosphere.
Biogeography The large-scale geographic pattern in the
distribution of species, and the causes and history of this
distribution.
Biohydromettalurgy Combining biological and mining processes,
usually involving microbes to help extract valuable
metals such as gold from the ground. May also be used to
remove pollutants from mining waste.
Biological control A set of methods to control pest organisms
by using natural ecological interactions, including
predation, parasitism, and competition. Part of integrated
pest management.
Biological diversity Used loosely to mean the variety
of life on Earth, but scientifically typically used as
to consisting of three components: (1) genetic diversity—
the total number of genetic characteri stics; (2) species
diversity; and (3) habitat or ecosystem diversity—the
number of kinds of habitats or ecosystems in a given unit
area. Species diversity in turn includes three concepts: species
richness, evenness, and dominance.
Biological evolution The change in inherited characteristics
of a population from generation to generation, which can
result in new species.
Biological production The capture of usable energy from
the environment to produce organic compounds in which
that energy is stored.
Biomagnification Also called biological concentration. The
tendency for some substances to concentrate with each
trophic level. Organisms preferentially store certain
chemicals and excrete others. When this occurs consistently
among organisms, the stored chemicals increase as
a percentage of the body weight as the material is transferred
along a food chain or trophic level. For example,
the concentration of DDT is greater in herbivores than
in plants and greater in plants than in the nonliving
environment.
Biomass The amount of living material, or the amount of
organic material contained in living organisms, both as live
and dead material, as in the leaves (live) and stem wood
(dead) of trees.
Biomass energy The energy that may be recovered from
biomass, which is organic material such as plants and animal
waste.
Biomass fuel A new name for the oldest fuel used by humans.
Organic matter, such as plant material and animal waste,
that can be used as a fuel.
Biome A kind of ecosystem. The rain forest is an example of
a biome; rain forests occur in many parts of the world but
are not all connected to each other.
Bioremediation A method of treating groundwater pollution
problems that utilizes microorganisms in the ground to
consume or break down pollutants.
Biosphere Has several meanings. One is that part of a planet
where life exists. On Earth it extends from the depths of
the oceans to the summits of mountains, but most life
exists within a few meters of the surface. A second meaning
is the planetary system that includes and sustains life, and
therefore is made up of the atmosphere, oceans, soils,
upper bedrock, and all life.
Biota All the organisms of all species living in an area or
region up to and including the biosphere, as in “the biota
of the Mojave Desert” or “the biota in that aquarium.”
Biotic province A geographic region inhabited by life-forms
(species, families, orders) of common ancestry, bounded by
barriers that prevent the spread of the distinctive kinds of
life to other regions and the immigration of foreign species
into that region.
Birth control The number born divided by the total number
in the population.
Birth rate The rate at which births occur in a population, measured
either as the number of individuals born per unit of
time or as the percentage of births per unit of time compared
with the total population.
Black lung disease Often called coal miner disease because it
is caused by years of inhaling coal dust, resulting in damage
to the lungs.
Body burden The amount of concentration of a toxic chemical,
especially radionuclides, in an individual.
Breeder reactor A type of nuclear reactor that utilizes
between 40% and 70% of its nuclear fuel and converts fertile
nuclei to fissile nuclei faster than the rate of fission.
Thus breeder reactors actually produce nuclear fuels.
Brines With respect to mineral resources, refers to waters
with a high salinity that contain useful materials such as
bromine, iodine, calcium chloride, and magnesium.
Buffers Materials (chemicals) that have the ability to neutralize
acids. Examples include the calcium carbonate that is present
in many soils and rocks. These materials may lessen potential
adverse effects of acid rain.
Burner reactors A type of nuclear reactor that consumes
more fissionable material than it produces.
Capillary action The rise of water along narrow passages,
facilitated and caused by surface tension.
Carbon cycle Biogeochemical cycle of carbon. Carbon combines
with and is chemically and biologically linked with
the cycles of oxygen and hydrogen that form the major
compounds of life.
Carbon monoxide (CO) A colorless, odorless gas that at
very low concentrations is extremely toxic to humans and
animals.
Carbon-silicate cycle A complex biogeochemical cycle over
time scales as long as one-half billion years. Included in
this cycle are major geologic processes, such as weathering,
transport by ground and surface waters, erosion, and