Glossary of Environmental Science - B

B

• backflow - movement of water back to source e.g. contaminated water in a plumbing system.
• baffle - (landscape design) an obstruction to trap debris in drainage water.
• bagasse - the fibrous residue of sugar cane milling used as a fuel to produce steam in sugar mills.
• baseload - the steady and reliable supply of energy through the grid. This is punctuated by bursts of higher demand known as “peak-load”. Supply companies must be able to respond instantly to extreme variation in demand and supply, especially during extreme conditions. Gas generators can react quickly while coal is slow but provides the steady "baseload". Renewable energies are generally not available on demand in this way.
• batters - (landscape design) the slope of earthworks such as drainage channels.
• best practice - a process, technique, or innovative use of technology, equipment or resources or other measurable factors that have a proven record of success.
• bioaccumulation - the accumulation of a substance, such as a toxic chemical, in the tissues of a living organism.
• biocapacity - a measure of the biological productivity of an area. This may depend on natural conditions or human inputs like farming and forestry practices; the area needed to support the consumption of a defined population.
• biocoenosis (alternatively, biocoenose or biocenose ) – all the interacting organisms living together in a specific habitat (or biotope).
• biodegradable - capable of being decomposed through the action of organisms, especially bacteria.
• biodiversity - the variety of life in all its forms, levels and combinations; includes ecosystem diversity, species diversity, and genetic diversity.
• bioelement - an element required by a living organism.
• bioenergy - used in different senses: in its most narrow sense it is a synonym for biofuel, fuel derived from biological sources. In its broader sense it encompasses also biomass, the biological material used as a biofuel, as well as the social, economic, scientific and technical fields associated with using biological sources for energy.
• biofuel - the fuel produced by the chemical and/or biological processing of biomass. Biofuel will either be a solid (e.g. charcoal), liquid (e.g. ethanol) or gas (e.g. methane).
• biogas - landfill gas and sewage gas, also called biomass gas.
• biogeochemical cycle - a circuit or pathway by which a chemical element or molecule moves through both biotic ("bio-") and abiotic ("geo-") parts of an ecosystem.
• biogeochemical cycles - the movement of chemical elements between organisms and non-living components of the atmosphere, aquatic systems and soils.
• biological oxygen demand (BOD) - a chemical procedure for determining how fast biological organisms use up oxygen in a body of water.
• biological pest control - a method of controlling pests (including insects, mites, weeds and plant diseases) that relies on predation, parasitism, herbivory, or other natural mechanisms.
• biological productivity - (bioproductivity) the capacity of a given area to produce biomass; different ecosystems (i.e. pasture, forest, etc.) will have different levels of bioproductivity. Biological productivity is determined by dividing the total biological production (how much is grown and living) by the total area available.
• biologically productive land - is land that is fertile enough to support forests, agriculture and / or animal life. All of the biologically productive land of a country comprises its biological capacity. Arable land is typically the most productive area.
• biomass - the materials derived from photosynthesis (fossilised materials may or may not be included) such as forest, agricultural crops, wood and wood wastes, animal wastes, livestock operation residues, aquatic plants, and municipal and industrial wastes; the quantity of organic material present in unit area at a particular time mostly expressed as tons of dry matter per unit area; organic matter that can be used as fuel.
• biome - a climatic and geographically defined area of ecologically similar communities of plants, animals, and soil organisms, often referred to as ecosystems.
• biophysical - the living and non-living components and processes of the ecosphere. Biophysical measurements of nature quantify the ecosphere in physical units such as cubic metres, kilograms or joules.
• bioregion - (ecoregion) an area comprising a natural ecological community and bounded by natural borders.
• bioremediation - a process using organisms to remove or neutralise contaminants (e.g. petrol), mostly in soil or water.
• biosolids - nutrient-rich organic materials derived from wastewater solids (sewage sludge) that have been stabilised through processing.
• biosphere - the part of the Earth, including air, land, surface rocks, and water, within which life occurs, and which biotic processes in turn alter or transform.
• biosphere - the zone of air, land and water at the surface of the earth that is occupied by living organisms; the combination of all ecosystems on Earth and maintained by the energy of the Sun; the interface between the hydrosphere, geosphere and atmosphere.
• biotic potential - the maximum reproductive capacity of a population under optimum environmental conditions.
• biotic - relating to, produced by, or caused by living organisms. (see also abiotic).
• birth rate - number of people born as a percentage of the total population in any given period of time; number of live births per 1000 people.
• blackwater - household wastewater that contains solid waste i.e. toilet discharge.
• bluewater - collectible water from rainfall; the water that falls on roofs and hard surfaces usually flowing into rivers and the sea and recharging the ground water. In nature the global average proportion of total rainfall that is blue water is about 40%. Blue water productivity in the garden can be increased by improving irrigation techniques, soil water storage, moderating the climate, using garden design and water-conserving plantings; also safe use of grey water.
• boreal - northern; cold temperate Northern Hemisphere forests that grow where there is a mean annual temperature < 0°C.
• broad-acre farm - commercial farm covering a large area; usually a mixed farm in dryland conditions.
• Brundtland Commission Report - a UN report, Our Common Future, published in 1987 and dealing with sustainable development and the policies required to achieve it, which the report characterizes as "development that meets the needs of the present without compromising the ability of future generations to meet their own needs."