The State of Canada's Environment — 1996

Glossary of Selected Terms - B

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Sources for definitions

bacillus thuringiensis (b.t., bt, or bt): A biological insecticide that was developed in Canada (Natural Resources Canada 1994). This bacterium, which occurs in soils everywhere, is sprayed on trees against the Spruce Budworm and other similar insects. The subspecies Bacillus thuringiensis israelensis (BTI) has been used by the city of Red Deer, Alberta, as a biocontrol agent for two species of mosquitoes that bite humans.

background extinction rate: Historical rates of extinction due to environmental causes not influenced by human activities, such as the rate of species going extinct because of long-term climate change (Meffe et al. 1994).

balance of trade in goods and services: Exports of goods and services less imports of goods and services (Statistics Canada 1994).

benthic: Of or living on or in the bottom of a water body (Upper Great Lakes Connecting Channels Study, Management Committee 1988). See also benthos and pelagic.

benthos: Organisms living on the bottom of bodies of water (Demayo and Watt 1993).

bioaccumulation: General term describing a process by which chemical substances are ingested and retained by organisms, either from the environment directly or through consumption of food containing the chemicals (Government of Canada 1991). See also bioconcentration and biomagnification.

biocentric: The view or perception that all living organisms on Earth have intrinsic value and that humans are in no way superior to other species (Environment Canada 1993). See also anthropocentric.

biochemical oxygen demand (bod): A measure of the quantity of oxygen used in the biochemical oxidation of compounds containing carbon and nitrogen in a specified time, at a specified temperature, and under specific conditions. The standard measurement is made for five days at 20°C (Demayo and Watt 1993).

bioconcentration: Ability of an organism to selectively accumulate certain chemicals, elements, or substances within its body or within certain cells. A process by which there is a net accumulation of a chemical directly from water into aquatic organisms resulting from simultaneous uptake (e.g., by gill) and elimination (Wells and Rolston 1991). See also bioaccumulationand biomagnification.

biodegradability: Characteristic of a substance that can be broken down by microorganisms (Demayo and Watt 1993).

biodegradable: Capable of being broken down by living organisms into inorganic compounds (Arms 1990).

biodegradation: Biochemical process for the breakdown of large, complex organic compounds into simple molecules (Demayo and Watt 1993).

biodiversity (biological diversity): The variability among living organisms from all sources including, inter alia, terrestrial, marine and other ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems (Federal-Provincial-Territorial Biodiversity Working Group 1995).

biodiversity indicators: Indicators or measures that allow the determination of the degree of biological or environmental changes within ecosystems, populations, or groups of organisms over time and space (Federal-Provincial-Territorial Biodiversity Working Group 1995).

biodiversity prospecting: The exploration of biodiversity for commercially valuable genetic and biochemical resources (Reid et al. 1993).

bioenergy: Energy that is produced from organic matter (both plant and animal) by burning or by a bioconversion method such as fermentation (Natural Resources Canada 1994).

biological diversity: See biodiversity.

biologically available: The physical or chemical form of a substance that can be directly used by an organism (Demayo and Watt 1993).

biomagnification: Cumulative increase in the concentration of a substance in successively higher levels of a food web (Environment Canada et al. 1988). See also bioaccumulation and bioconcentration.

biomass: Quantity of living matter in a defined area expressed in units of living or dead mass (Demayo and Watt 1993). Typically measured as the weight of all dried organic matter in a defined area of a particular ecosystem. In the energy field, any form of organic matter (from both plants and animals) from which energy can be derived by burning or bioconversion (e.g., fermentation) (Wells and Rolston 1991).

biosphere: Refers to the biological components of the ecosphere (E.B. Wiken and A.M. Turner, State of the Environment Directorate, Environment Canada, personal communication).

biota: Collectively, the living organisms in a given ecosystem, including bacteria and other microorganisms, plants, and animals (Demayo and Watt 1993).

biotechnology: The application of science and engineering in the direct or indirect use of living organisms or parts or products of living organisms in their normal or modified forms (Government of Canada 1988).

biotic: Refers to the living elements of an ecosystem, such as plants and animals (Environment Canada 1993).

bleached kraft pulp mill: A pulp and paper mill that produces coarse white paper of great strength from wood pulp using the chlorine pulping process (Eade 1994).

bloom: (also known as algal bloom) Rapid growth of certain algal constituents of plankton in and on a body of water that is so heavy as to colour the water (Demayo and Watt 1993). The rapid growth can be fuelled by enrichment of nutrients, such as phosphorus and nitrogen.

bod: See biochemical oxygen demand.

buffer zone: An area in a reserve or other protected area surrounding the central core zone, in which nondestructive human activities such as ecotourism, traditional (low-density) agriculture, or extraction of renewable natural products are permitted (Meffe et al. 1994).