Glossary

Independent report to the Australian Government Minister for the Environment and Heritage
Beeton RJS (Bob), Buckley Kristal I, Jones Gary J, Morgan Denise, Reichelt Russell E, Trewin Dennis
(2006 Australian State of the Environment Committee), 2006

Glossary

aerosol
a suspension of particles, other than water or ice, in the atmosphere that ranges in size from about 5 nm to larger than 10 μm in radius. It may be either natural or caused by human activity, and most of the latter are usually considered to be pollutants.
air toxics
gaseous, aerosol or particulate pollutants (other than the six criteria pollutants) present in the air in low concentrations with characteristics such as toxicity or persistence so as to be a hazard to human, plant or animal life
algal bloom
a sudden proliferation of microscopic algae in water bodies, stimulated by the input of nutrients such as phosphates
anthropogenic
of human origin or human induced
aquaculture
commercial growing of marine (mariculture) or freshwater animals and plants in water
aquifer
an underground layer of soil, rock or gravel able to hold and transmit water. Bores and wells are used to obtain water from aquifers.
arid zone
the arid and semi-arid lands are those remote and sparsely populated areas of inland Australia, defined by the presence of desert vegetation and land forms as well as by low rainfall. They are bound by median annual rainfalls of about 250 mm in the south but up to 800 mm in the north and about 500 mm in the east.
average temperature
in Australia, the average (or mean) temperature is always taken as the maximum plus minimum, divided by two. For a continental-scale average, the calculation is done in two steps. The minimum temperatures from all weather stations at a point in time are averaged to get the average minimum temperature across the continent; similarly, all maximum temperatures from weather stations are averaged to get the average maximum temperature across the continent. These two averages are then averaged again to get the average temperature across Australia.
ballast water
water carried in tanks to maintain stability when a ship is lightly loaded; it is normally discharged to the sea when the ship is loaded with cargo
biodiversity
variability among living organisms from all sources (including terrestrial, marine and other ecosystems and ecological complexes of which they are part), which includes diversity within species and between species and diversity of ecosystems
biomass
the quantity of organic matter within an ecosystem (usually expressed as dry weight for unit area or volume)
bioregion
an area defined by a combination of biological, social and geographical criteria rather than by geopolitical considerations; generally, a system of related, interconnected ecosystems
biota
all of the organisms at a particular locality
blue-green algae
an ancient order of algae (with characteristics of bacteria) that have become more common in water bodies due to disturbance and pollution. Some species produce toxins that can cause sickness and nerve and liver damage.
bycatch
species taken incidentally in a fishery where other species are the target. Some bycatch species are of lesser value than the target species, so are often discarded but other bycatch species have some commercial value (‘byproduct’) and are retained for sale.
catchment
an area determined by topographic features within which rainfall will contribute to runoff at a particular point under consideration
CO2-e
carbon dioxide equivalent
conservation
in relation to biodiversity: the protection, maintenance, management, sustainable use, restoration and enhancement of the natural environment; in relation to natural and cultural heritage: generally, keeping in safety or preserving the existing state of a heritage resource from destruction or change
conservation estate
those parts of the environment that are formally reserved for conservation of native species, ecosystems and recreation  
contaminated site
a site at which hazardous substances occur at concentrations above background levels and where assessment shows this poses, or is likely to pose, an immediate or long-term hazard to human health or the environment
cultural landscape
encompasses the qualities and attributes of places that have aesthetic, historic, scientific or social value for past, present or future generations. These values may be seen in a place’s physical features, but importantly can also be intangible qualities such as people’s associations with, or feelings for a place.
de-snag
to remove the ‘snags’ (fallen trees) lying in the river channel of lowland rivers. Snags are common in Australian rivers, but they interfere with recreational uses like water skiing and look unsightly and so are often removed. In the past, they were also removed in the mistaken belief that they had a major effect on reducing the flood carrying capacity of rivers.
dryland salinity
a condition wherein soil salinity levels in an area are high enough to affect plant growth
ecological community
the definition of an ecological community in the EPBC Act is as follows: ‘an assemblage of native species that: (a) inhabits a particular area in nature; and (b) meets the additional criteria specified in the regulations (if any) made for the purposes of this definition’
ecosystem
a dynamic complex of plant, animal and microorganism communities and their non-living environment that interacts as a functional unit
El Niño
an extensive warming of the central and eastern Pacific Ocean that leads to a major shift in weather patterns across the Pacific. In Australia (particularly eastern Australia), El Niño events are associated with an increased probability of drier conditions.
endangered
when referring to the state of Indigenous languages, there are several categories including the severely and critically endangered categories. These languages are only spoken by small groups of people mostly over 40 years old.
endemic
native to a particular area and found nowhere else
energy efficiency
the means of using less energy in doing the same amount of work
enhanced greenhouse effect
the addition to the natural greenhouse effect resulting from human activities such as the burning of fossil fuels and land clearing, which increase the atmospheric levels of greenhouse gases such as carbon dioxide, methane, nitrous oxide, ozone and chlorofluorocarbons (CFCs)
environment
includes ecosystems and their constituent parts, including people and communities; natural and physical resources; the qualities and characteristics of locations, places and areas; and the social, economic and cultural aspects of a thing mentioned in the previous three categories
environmental indicators
are the physical, chemical, biological or socio-economic measures that best represent the key elements of a complex ecosystem or environmental issue. Indicators can organise environmental information both spatially and over time. An example is ‘surface water used for irrigation’.
exceedances
those times when a measurement of a component goes beyond a specified limit
fire regime
the pattern of fires at a location; includes the frequency, intensity and seasonality of the fires
forest
this report uses an international definition of forest. Under this definition, forest is native and non-native vegetation that has at least 20 per cent canopy cover and could grow to at least two metres tall. Only patches of more than 0.2 hectares are included. The forest change analysis used for these calculations therefore involves only deforestation and forest regrowth data that is human induced, so it does not include commercial forestry operations, or loss of vegetation due to fire or dieback. The data have been independently verified.
greenhouse effect
see enhanced greenhouse effect
greenhouse gas emissions
releases of those gases that, by affecting the radiation transfer through the atmosphere, contribute to global warming
groundwater
the water beneath the surface that flows naturally to the earth’s surface via seeps or springs, that can be collected with wells, tunnels or drainage galleries
heritage objects
material that is in situ at significant sites or held in collecting institutions such as archives, libraries, museums, galleries, zoos, herbaria or botanic gardens, or historic buildings
hydrocarbons
organic molecules containing hydrogen and carbon; the major components of petroleum
Indigenous
of or relating to the Aboriginal and Torres Strait Islander peoples of Australia
intensive land use zone (ILZ)
the area of Australia where intensive land use practices such as irrigated agriculture occur
intertidal
between the levels of low and high tide
invasive species
a species spreading beyond its accepted normal distribution as a result of human activities and which threatens valued environmental, agricultural or personal resources by the damage it causes
invertebrate
an animal without a backbone composed of vertebrae (eg insects, worms, snails, mussels, prawns and cuttlefish)
in-water operations
a number of methods used for farming aquatic animals, in the sea in Australia, including cages, ropes, rafts and racks
La Niña
warming of the western equatorial Pacific warm pool, north of New Guinea, accompanied by cooling in the equatorial eastern Pacific Ocean. La Niña is often associated with above average rainfall in eastern Australia (see El Niño).
Landcare
a programme to further sustainable land management
managed decay (for cultural heritage)
involves extensive documentation, removal of hazardous material, eg poisonous chemicals, followed by minimal intervention and monitoring to enable decisions to be made to decrease the demise of artefacts, for example objects that are at risk due to exposure to a harsh environment can be relocated to more protected areas.
mangrove
a plant (belonging to any of a wide range of species, mainly trees and shrubs) that grows in sediment regularly inundated by sea water
marine area
area of sea or sea bed over which a country has jurisdiction under the Law of the Sea Convention. For Australia it includes the Australian Exclusive Economic Zone around the mainland, islands and the Australian Antarctic Territory and the continental shelf off the mainland and the Australian Antarctic Territory.
molluscs
a phylum of invertebrates, including snails, clams, octopuses, squids, and others
Montreal Protocol
the Montreal Protocol on Substances that Deplete the Ozone Layer, agreed in Montreal in 1987
National Environment Protection Measures
broad framework-setting statutory instruments defined in the National Environment Protection Act 1994 (see http://www.nepc.gov.au >)
natural places
those sites, areas or regions for which the heritage significance is based on their natural biological and physical features; may also have cultural heritage values
Natural Heritage Trust
a body established by the Natural Heritage Trust of Australia Act 1997 to stimulate conservation, sustainable use and repair of Australia’s natural environment
net consumption
the amount of natural resources used per person per year less the wastes produced that are recycled or reused. This includes household, industrial, mining and agricultural wastes of which only a small portion are recycled.
old-growth forests
forests dominated by mature trees and with little or no evidence of any disturbance such as logging, road building or clearing
ozone depletion
a disturbance of the natural equilibrium between chemical reactions forming and destroying stratospheric ozone; caused by the release of manufactured chemicals
ozone layer
a region in the stratosphere where there is a small, but significant, amount of ozone
Percentile (as in mathematics):
represents the relative position or rank of each priority score (along a 100 percentile band) among the scores assigned by a particular study section.
photochemical smog
air pollution caused by chemical reactions among various substances and pollutants in the atmosphere in the presence of sunlight; ozone is a major constituent
PM10 and PM2.5
particles with aerodynamic diameters of up to 10 μm and 2.5 μm, respectively
point-source pollution
pollution from an easily discernable, single source such as a factory or sewage treatment plant
potable water
water pure enough for humans to drink
potential evaporation
the amount of evaporation that would occur if a sufficient water source were available. Surface and air temperatures, solar radiation, and wind all affect this.
Ramsar Convention
the Convention on Wetlands, signed in Ramsar, Iran, in 1971 providing the framework for the conservation and wise use of wetlands and their resources. There are presently 122 Contracting Parties to the Convention, with 1031 wetland sites, totalling 78.2 million hectares, designated for inclusion in the Ramsar List of Wetlands of International Importance. Wetlands are referred to as Ramsar wetlands if they are included in the Ramsar List.
rangelands
native grasslands, shrublands and woodlands that cover a large proportion of the arid and semi-arid zones, and also include tropical savanna woodlands; regular cropping is not practised and the predominant agricultural use, if any, is grazing by sheep and cattle on native vegetation
Register of the National Estate
a national inventory of places of natural, historic and Indigenous heritage significance deemed to be worth conserving for present and future generations
re-snag
the process of replacing natural river snags and large woody debris to encourage freshwater fish habitat rehabilitation
riparian vegetation
plant communities on the fringes of and adjacent to water bodies
river salinity
concentrations of salt in rivers and creeks caused by saline discharges from dryland, irrigation and urban salinity
runoff
the portion of rainfall not immediately absorbed into the soil and which becomes surface flow
salinisation
the process by which land becomes salt-affected
sand slug
large deposits of sand or other fine material in the beds of rivers. The material comes from gully erosion in the catchment. These sand deposits fill up the river channel, alter the original form of the riverbed and move slowly downstream if flooding occurs.
salinity
the concentration of salts in water and/or soil
sea-cage
sea-cages are square or circular, floating pens used for commercial farming of marine animals such as southern blue fin tuna 
sea change
a fundamental lifestyle change and accompanying relocation to certain non-metropolitan areas on the coast
seagrass
intertidal and subtidal flowering plants found mainly in shallow waters of protected coastal areas
semi-arid zone
an area where rainfall is so low and unreliable that crops cannot be grown with any reliability (see also arid zone)
soil acidity
a condition in which the surface soil pH has declined to less than pH 5.5 as a result of human activity (such as agriculture)
Southern Oscillation
a fluctuation in atmospheric circulation, in particular over the tropical areas of the Pacific and Indian oceans; in general, when atmospheric pressures are high over the eastern Pacific Ocean they tend to be low in the eastern Indian Ocean and vice versa; the fluctuation between the two produces a marked variation in parameters such as the sea surface temperature and rainfall over a wide area of the Pacific and has a cycle of two to seven years; the phenomenon is influenced by the El Niño
sustainable
with respect to an activity, able to be carried out without damaging the long-term health and integrity of natural and cultural environments
threatened
of or relating to a species or community that is vulnerable, endangered or presumed extinct (as defined in the Environment Protection and Biodiversity Conservation Act 1999)
threatening process
a process that threatens, or may threaten, the survival, abundance or evolutionary development of a native species or ecological community
tree change
a fundamental lifestyle change and accompanying relocation to certain non-metropolitan areas, especially localities within striking distance of the bigger cities
turbidity
the extent to which the passage of light through water is reduced by suspended matter
urban water supply
a typical urban water supply system begins at the catchment source such as a river. Water is pumped from the source to a treatment plant where sediment and contaminants are removed and chlorine disinfection kills microbiological organisms. Water is distributed via localised storage tanks and pipes to the community.
urban stormwater
urban stormwater is runoff from urban areas, including the major flows during and following rain as well as dry weather flows
volatile organic compound (VOC)
carbon-containing compounds occurring in ambient air as gases or vapour with boiling points between 50°C and 260°C. The VOCs that participate in smog formation reactions are called reactive organic compounds (ROCs) (e.g. benzene, xylene and toluene).
wastewater
water that has been generated or used by humans, or in industrial processes
World Heritage sites
sites of outstanding universal natural or cultural significance that are included on the World Heritage List