An epiphytic plant (such as a vine) whose aerial roots extend down the trunk of a supporting tree and grow around it, eventually strangling the tree. …
The systematic process of evaluating the environmental impacts of a policy, plan, or programme and its alternatives, including the preparation of a report on the evaluation and the use of the findings in publicly accountable decision‐making. See also environmental impact assessment. …
Lawsuits that have no merit in themselves but are brought against private citizens who act in the public interest, usually by a large corporation of a wealthy individual, in order to intimidate them and silence them by burdening them with huge costs of legal defence. …
Any mineral that a country uses (for example for defence purposes) but which it cannot produce itself. …
A plan that an organization develops in order to help align its structure and resources with defined priorities, missions, and objectives. …
A statement or framework that describes how a particular programme will achieve its desired goals and objectives. …
To separate into layers (strata), such as the layers (lamination) within a sedimentary rock, or the layers of vegetation within a tropical rainforest. See also thermal stratification. …
Well‐sorted layers of sand and gravel that have been deposited by glacial meltwater. …
An estuary in which freshwater from the land lies on top of denser saltwater from the sea. …
Seed that has been stored in a cool, moist environment in order to develop to the point where it can germinate. …
The layers (strata) of vegetation within a forest, which are defined by species, age, or size of plant into the tree layer, shrub layer, and herb layer. See also canopy, overstorey, understorey. …
A cloud that develops horizontally rather than vertically. …
Relating to or determined by the layers (strata) within a sediment or sedimentary rock. …
The series of layers (strata) within a sediment or sedimentary rock, which can be interpreted by stratigraphy. …
A group of closely related layers (strata) within a sedimentary rock. …
The study of the origin, composition, distribution, and succession of strata in sedimentary rocks, on the basis of fossil content (biostratigraphy) and lithology (lithostratigraphy). …
A soft, grey, rolling low cloud which is usually found below about 2400 metres, has a flat base and rounded top, is thicker than stratus, and is often accompanied by weather changes and precipitation. …
The boundary in the atmosphere between the stratosphere and the mesosphere, at a height of about 50 kilometres, where the air temperature is about 0?C. …
The layer of the atmosphere between the troposphere (below) and the mesosphere (above), the lower level of which varies with latitude from about nine kilometres at the poles to 16 kilometres near the equator, and which extends to an altitude of around 50 kilometres. In this layer there is little water vapour but much ozone, and temperature remains stable or rises slightly with altitude. The strato…
Ozone that is found in the stratosphere. It blocks out harmful ultraviolet rays from the Sun, including those that may cause damage to human health and the environment. Contrast tropospheric ozone. See also ozone layer. …
A sequence of sediment or rock at a particular place, in which a stratigraphic unit or boundary is defined, which is used as a global standard for comparing all other stratigraphic units of its kind (defined by age and lithology). …
A volcanic cone that consists of both lava and pyroclastic rocks. …
A horizontal layer of sedimentary rock or vegetation. (plural strata). See also stratification. …
A thick, grey, flat, low‐level type of cloud, the most common of all low clouds, which rarely extends higher than about 1500 metres, can produce drizzle or snow but rarely produces heavy precipitation, and creates fog when it touches the ground. Stratus clouds are commonly found during the winter in humid climates in middle and high latitudes, and can persist for days or weeks. …
The plant residue that remains after seeds are removed in threshing. …
The colour of a mineral when it is in powdered form. …
A natural body of running water that flows along a channel. See also creek, river. …
The sides of a stream channel. Also known as river bank . …
The bottom of a stream channel. Also known as river bed . …
A watercourse, or natural channel along which water flows. Also known as river channel . …
The rate of flow of water along a stream over a given period of time, which depends on volume and velocity of flow, and is usually expressed in cubic metres per second (m3 s-1). …
Discharge that occurs in a natural stream channel, which includes runoff and water that is added or removed through diversion or flow in a regulated river. …
The number of stream segments per unit drainage area (usually per square kilometre). Dense networks have high stream frequencies. Contrast drainage density. …
The curved path of any medium (such as a parcel of air or a flow of water or ice) that flows steadily over or around an obstacle. …
The relative position or rank of a stream segment in a drainage network, with the smallest permanent streams defined as first order, second order defined as where two first‐order streams join, third order as two second‐order streams join, and so on. …
A reach of a stream channel, usually defined as between two successive tributaries. …
A buffer zone or strip of permanent undisturbed vegetation (usually forest or grass) that is left between a stream and an adjacent area of more intensive land use (such as agriculture or urban development). It is designed to reduce soil erosion and protect water quality by filtering out pollution before it reaches the water. See also riparian. …
An area adjacent to a stream in which vegetation is maintained or managed in order to protect water quality, provide diversity of habitat, and create wildlife travel corridors. …
A system for classifying streams according to the intended use of the water, such as for recreation or irrigation. …
Any public thoroughfare or residential road that leads off a main road. …
1 The force per unit area that is applied to a body, and produces strain on that material. 2 A physical or chemical process that causes a response within an organism, population, or ecosystem. …
A scratch mark that is caused by abrasion of the surface of a rock by a glacier, is aligned in the direction of ice movement, and is very useful in reconstructing directions of ice movement in the past. Also known as striae . …
The direction or trend of a bedding plane or fault, relative to the horizontal. …
A horizontal displacement fault (such as the San Andreas fault in California), in which movement occurs along the fault line as a result of shearing. Also known as transcurrent fault . …
In forest management, a system of clearcutting in narrow strips in order minimize edge effects and allow natural regeneration of the forest. …
A sprawling form of commercial land use in which each establishment is given direct access to a major thoroughfare, which usually has many large signs designed to attract passers‐by. Visitors drive to and from the strip, which therefore requires extensive parking areas. …
Planting different crops in alternating strips along land contours, so that when one is harvested the other remains to protect the soil and prevent erosion. Also known as strip cropping . …
North American term for a shopping centre (shopping mall) that consists of a continuous line of single‐storey shops, stores, businesses, and restaurants along a road or busy street, usually opening onto a car park. Contrast shopping mall. …
The mining of ore or coal from an open mine, which usually involves the use of large machines (bulldozers, power shovels, or stripping wheels) that scoop out the material in long, narrow strips. The two main types are area mining and contour mining. …
A Canadian industrialist and public servant (born 1929 ) who was the first Executive Director of the United Nations Environment Programme. He served as Secretary‐General of the 1992 United Nations Conference on Environment and Development and as a senior advisor to UN Secretary‐General Kofi Annan . …
The state of balance between the pressure gradient (which forces air to move from high to low pressure) and the Coriolis force (which acts in the opposite direction), and causes wind generally to blow at right angles to the pressure gradient (deflected to the right in the northern hemisphere and to the left in the southern hemisphere). …
1 The way in which something is organized, such as the pattern of plant species within an ecosystem. 2 Anything that is built for the support, shelter, or enclosure of people, animals, goods, or property. …
A statutory land use plan agreed by a county planning authority in the UK, which sets out strategic policies for town and country planning within that county. Contrast Local Plan. …
The short stalks that are left behind in a field after the crop has been harvested. …
A soil covering that is composed of the unused stalks of crop plants (stubble). …
The lower part of a tree that remains standing after the tree has been felled or coppiced. …
A long mouth part of an insect, which is normally used to extract fluids. …
A genus of minute insects (of the group Strepsiptera), which in their larval state are parasitic on bees and wasps. …
The high latitude area in the northern hemisphere which has a subarctic climate. …
A climate zone that is found across much of North America and most of northern Eurasia, north of the humid continental climate and south of the polar climate in the northern hemisphere, and is characterized by bitterly cold winters and short cool summers. …
Smaller than an atom, or relating to the constituents of an atom or the forces within an atom. …
A form of arrested development of vegetation, where a succession has been retarded or inhibited by natural arresting factors such as natural fires, storms, or lack of long‐term environmental stability. …
The act of subdividing land (for example into sites, blocks, or lots with streets or roads and open spaces), or the area of land that has been divided up. …
The process that takes place within plate tectonics when two crustal plates converge and one plate is forced below the other into the mantle. …
A zone in the Earth's crust where one crustal plate is pushed downwards into the mantle beneath an adjacent one, driven by sea‐floor spreading. …
One of two or more groups of closely related species that constitute a genus. …
Beneath a glacier or ice cap. Contrast englacial, supraglacial. …
A meltwaterstream that flows underneath a glacier or ice cap. …
A warm, moist climate which supports grassland or prairie vegetation. …
The direct alteration (phase change) of ice (solid) to water vapour (gas). …
Of or relating to the region of the continental shelf, lying the sea shore and the edge of the continental shelf. …
The upper part of the sublittoral zone, which is uncovered at low tide. …
A zone within the ocean that extends from the low tide mark to the edge of the continental shelf, with depths of up to about 300 metres. …
Vegetation that lives at or below the surface of a waterbody. …
The coldest of the world's climate zones that is found at high latitudes, and contains continental subarctic, marine subarctic, and arctic and ice cap climates. …
A climate zone that is found in the northern hemisphere, south of the polar climate, and is characterized by severely cold winters and short, cool summers. Also known as boreal climate or taiga climate . …
A major wind belt that circles the Earth, in that easterly winds generated by the polar high converge with westerly winds from the subtropical high, at the subpolar low pressure belt, at about 60? latitude. Weather here is often very unsettled, with extensive cloud cover. …
A subset of a natural or artificial breeding population. See also variety. …
1 In meteorology, the slow sinking of air that is usually associated with high pressure areas. 2 In geology, a settling of the ground surface as a result of the collapse of porous formations from which large amounts of groundwater, oil, or other underground materials have been withdrawn. …
A temperature inversion that develops in the atmosphere as a result of air gradually sinking over a wide area and being warmed by adiabatic compression, often associated with subtropical high pressure areas. …
A grant that is paid by government to the supplier of a good or service that benefits the public. …
The means of obtaining food and other items that are essential for basic survival. …
An economy in which production meets the minimum needs of the population, but produces no surplus. …
Cultivation of crops and livestock in order to provide for the basic needs of the farmer and his/her family, without producing surpluses that can be sold at market. Contrast cash crop. …
The lower part of a soil profile, beneath the topsoil, which generally contains little organic matter. …
A geographically isolated or physiologically distinct group within a species, which is capable of interbreeding with other members of the subspecies but rarely does so. Also known as a race . See also cultivar, variety. …
The degree to which one material can be replaced or exchanged for another. …
The surface on which a plant or animal lives and grows; for example a rocky or sandy substrate. Also known as substratum . …
The removal of excess water from within a soil or deposit, often by means of tile drains. …
The extraction of metal ore or fossil fuel resources from beneath the surface of the ground. …
The region between the tropical and temperate regions, which extends between about latitudes 35? and 40? North and South. …
A zone of temperature transition in the upper troposphere over subtropical latitudes, where warm air that is carried towards the poles by the Hadley cell meets the cooler air of the middle latitudes. …
A semipermanent zone of high pressure that is found in subtropical latitudes. …
A strong, generally westerly wind in the upper troposphere that blows over subtropical latitudes. See also jet stream. …
The outer part of a city or urban area, close to the urban?rural boundary, with limited commercial land use and low‐density residential development. Also known as suburbia . See also exurbia. …
Relating to, characteristic of, or situated in suburbs. See also urban. …
The growth of a metropolitan area, particularly the suburbs, over a large area. Also known as sprawl, urban sprawl, or Los Angelization . …
A rank of coal that is intermediate between lignite and bituminous coal. Also known as black lignite . …
1 In general, a sequence or the action of following in order. 2 In ecology, the gradual and orderly sequence of different plant communities that develop over time in the same area, as one community replaces another through a predictable series of stages (seres), until a stable climax is established. The sequence normally involves five stages, beginning with creation of an area of bare land (nudati…
A plant (such as a desert cactus) that is adapted to life in very dry conditions, often by having a soft fleshy body which can store water for use during times of drought. …
A shoot that grows from the stem of the plant below ground level. …
A North American term for land that is managed for timber production. Also known as suitable timber land . …
A North American term for land that produces or is capable of producing enough forage for grazing by livestock on a sustainable basis, under intensive management, without causing environmental damage. …
An aerosol that consists of compounds of sulphur formed by the interaction of sulphur dioxide and sulphur trioxide with other compounds in the atmosphere. These come from natural sources (particularly volcanic eruptions) and from the combustion of fossil fuels and the eruption of volcanoes like Mount Pinatubo. …
An ion that contains sulphur and oxygen (SO4), which react easily with hydrogen to become sulphuric acid (H2SO4). It is one of seven major ions that are found naturally in most waterbodies, and is a good indicator of water pollution. …
A micro‐organism that exists in an anaerobic environment and reduces sulphate to hydrogen sulphide. …
The amount of sulphur that is found in a particular coal, which strongly influences the amount of sulphur dioxide that is released on combustion and thus affects acid rain. …
The biogeochemical cycle by which sulphur circulates within the biosphere. The sedimentary and atmospheric phases are both important in the sulphur cycle (unlike the nitrogen and carbon cycles), and they are of comparable size. One source of sulphur is volcanoes. Although major volcanic eruptions are relatively infrequent, and so release relatively small amounts of sulphur overall, when they do oc…
A colourless, poisonous gas that is formed by burning sulphur to create an oxide, most commonly by the burning of fossil fuels that contain sulphur in order to generate electricity in power stations. The sulphur dioxide is released into the atmosphere as an air pollutant, and can cause acid rain. It is a conventional or criteria pollutant, and can give rise to trans‐frontier pollution. The amoun…
An abundant, tasteless, odourless, yellowish, non‐metallic solid element that is found in hydrocarbons, which release sulphur dioxide when burned. It is one of nine macronutrients which plants require for healthy growth, and is an important but small constituent of some proteins. …
A colourless gas that is soluble in alcohol and ether. It is a powerful greenhouse gas that is widely used in the electrical utility industry to insulate high‐voltage equipment. It has a global warming potential of 24?900 and persists in the atmosphere for up to 3200 years. It is one of the six greenhouse gases to be limited under the Kyoto Protocol. …
A toxic, corrosive, strongly acid, colourless compound that is formed when sulphur oxides combine with atmospheric moisture, and is a major ingredient of acid rain. …
The warmest season of the year, between springand autumn/fall, when the Sun is highest in the sky. Astronomically this is the period between the summer solstice and the autumnal equinox, which covers the months of June, July, and August in the northern hemisphere, and December, January, and February in the southern hemisphere. …
The longest day of the year, when the Sun is highest in the sky (because of the Earth's tilt), which marks the start of the summer season. This occurs in the northern hemisphere on or near 21 June , and in the southern hemisphere on 21 or 22 December . See also solstice, winter solstice. …
A pit or tank that is used to catch liquid runoff for drainage or disposal. …
The star at the centre of our solar system, around which the planets (including the Earth) orbit. It radiates energy (particularly heat and light) derived from thermonuclear reactions in its interior. The Earth is on average about 150 million kilometres away from the Sun, but this varies between 147 million and 152 million during the elliptical orbit. In galactic terms our Sun is quite insignifica…
A small, bowl‐shaped depression in ice that is melted by insolation. …
The light or rays from the Sun. See also solar heating. …
The first light of day, as the Sun rises above the horizon in the morning. …
The time in the evening at which the Sun begins to fall below the horizon. Also known as sundown . …
A dark‐coloured region on the surface of the Sun that represents an area of cooler temperatures and intense magnetic fields. The number of sunspots is greater when the Sun is more active. Sunspots vary in size from about 1500 kilometres to groups up to 200?000 kilometres in diameter. They constantly change size and appearance. Most spots appear and disappear within a day or so, but some last lon…
A severe thunderstorm that is characterized by a rotating, long‐lived, intense updraft (mesocycle), which produces severe weather, including extremely large hailstones, damaging winds, and violent tornadoes. Also known as a mesocyclone . …
Liquid water droplets at temperatures well below 0?C that would freeze immediately if particles were present to start the freezing process. …
Water which has undergone a thermal treatment in which moderate temperatures and high pressures are used to increase its ability to break down large organic molecules into smaller, less toxic ones by combining oxygen with simple organic compounds to form carbon dioxide and water. …
A fund established by Congress in the USA under the 1980 Comprehensive Environmental Response, Compensation, and Liability Act, financed by fees paid by toxic waste generators and by cost recovery from cleanup projects, in order to pay for the cleanup of inactive and abandoned hazardous waste sites or hazardous materials that have been accidentally spilled or illegally dumped. Also known as the …
US legislation that amended the 1986 Comprehensive Environmental Response, Compensation, and Liability Act to provide additional funding for environmental cleanup of hazardous waste sites. …
In the USA, a programme of the Environmental Protection Agency designed to promote the development and use of innovative treatment technologies in the cleanup of Superfund sites. …
See Comprehensive Environmental Response, Compensation, and Liability Act. …
A river network in which an initial pattern, determined by original rock structures and types, has been preserved as the river has cut down through underlying rocks, superimposing the original pattern on underlying structures and rock types. …
The basis for interpreting the stratigraphic sequences within sedimentary rocks, based on the assumption that older rocks are overlain by younger rocks so long as the rocks have not been disturbed by folding, faulting, or other geological processes. This helps geologists to establish a relative chronology of deposition, and to make geological associations from place to place. …
A condition that occurs when the relative humidity of air in the atmosphere is greater that 100%. …
A relative humidity of more than 100% in the atmosphere. …
Faster than the speed of sound in the surrounding air. See also Mach. …
A jet aeroplane that flies faster than the speed of sound (Mach > 1). …
A requirement within the Kyoto Protocol that adequate domestic energy and other policies exist to ensure the achievement of long‐term emissions reduction goals. See also flexibility mechanism. …
Feed (such as hay or silage, feed blocks or concentrates) that is used to supplement the dietary requirements of livestock, usually during the winter. …
The quantity of a good or service that producers are willing to provide at the specified price, time period, and condition of sale. Contrast demand. See also market equilibrium, supply schedule. …
A series of business transactions that starts with raw material and ends with the sale of the finished product or service. …
The relationship between price and the quantity of a good or service that producers are willing to provide. …
One of the four major crown classes in trees, in which trees which have crowns below the general level of the crown cover receive no direct light either from above or from the sides. Also known as overtopped . …
In fire management, all of the activities involved in extinguishing or containing a fire, starting with its discovery. …
On top of a glacier or ice cap. Contrast englacial, subglacial. …
A meltwaterriver that flows over the surface of the ice in a glacier or ice cap. …
The temperature of the air near the surface of the Earth, the global average of which is 15?C. …
The horizontal movement of seawater at the surface of a sea or ocean. …
The removal of excess water from the surface of the ground, either naturally by a stream, or artificially by means of a drainage ditch. …
A forest fire of moderate intensity in which low vegetation (such as shrubs) and some of the surface (bark) of trees are burned, but not the crowns of trees, so the trees survive. …
A deposit of ice crystals that builds up on a surface when the temperature of the surface is colder than the air above and colder than the frost point of that air. See also hoar. …
Any natural or constructed facility that is used to store liquids on the ground surface, including water storage ponds and lagoons. …
The lowest few metres of the atmosphere, or the upper few metres of the ocean, within which the air or water is mixed by the wind. …
US legislation that established a programme for the regulation of surface mining activities and the reclamation of coal‐mined lands, under the administration of the Office of Surface Mining, Reclamation and Enforcement, in the Department of the Interior. …
Any renewable resource (such as timber) that is found on the surface of the Earth, in contrast to resources such as groundwater and minerals which are found beneath the surface. …
Ownership of or rights to use the surface of the land. Subsurface rights (including mineral rights) are often treated separately. …
All forms of natural storage of water (including ponds and depressions) on the ground surface. …
The tension of the surface film of a liquid, which controls the shape of the liquid surface. …
All water that is naturally open to the atmosphere, including rivers, lakes, reservoirs, ponds, streams, impoundments, seas, estuaries, and wetlands. …
A soluble chemical compound that reduces the surface tension between two liquids, as used in many detergents. …
The zone of wave action that extends from the shore out to the most seaward point of the zone (the breaker zone) at which waves approaching the coastline start to break. …
1 A sudden forceful flow, for example in the flow of a glacier. 2 A large, destructive ocean wave that is created by very low atmospheric pressure and strong winds, for example associated with a hurricane. …
Excess; a quantity that is much larger than is needed. …
The ongoing systematic collection, collation, and analysis of data and the timely distribution of information to those who need to know so that action can be taken. …
1 A drawing showing the legal boundaries of a property. 2 A count or census of the number of individuals in an area, from which inferences about the population can be made. …
The condition of outliving others; the likelihood of a representative newly born individual surviving to various ages. Contrast longevity. …
The curve that describes changes in mortality rate as a function of age. …
The degree to which an organism is sensitive to a particular factor, such as infection by a pathogen. See also sensitivity. …
The fine particles of sediment that are carried in suspension by a river, when turbulent mixing exceeds gravitational sinking. Also known as suspended load . …
Solids (colloidal and particulate matter such as clay, sand, and finely divided organic material) that either float on the surface of water or are suspended in it. Suspended solids can usually be removed by filtering. …
A mixture in which fine particles are suspended in a fluid, supported by buoyancy. …
Any organism (such as sponges and corals) that feeds on particulate organic matter (including plankton) that is suspended in a water column. Also known as a filter feeder or suspensivore . …
A concept that is used to describe community and economic development in terms of meeting the needs of the present without compromising the ability of future generations to meet their needs. See also ecological sustainability, sustainable development. …
A measure (indicator) of sustainable development. …
Capable of being sustained or continued over the long term, without adverse effects. …
An agricultural system that is ecologically sound, economically viable, and socially just. Sustainable agriculture uses techniques to grow crops and raise livestock that conserve soil and water, use organic fertilizers, practice biological control of pests, and minimize the use of non‐renewable fossil fuel energy. …
A community of people that is capable of maintaining its present level of growth without damaging effects. …
According to the World Commission on Environment and Development (WCED), sustainable development is ?development that meets the needs of the present without compromising the ability of future generations to meet their own needs?, which includes economic growth together with protection of the quality of the environment, each reinforcing the other. Many of the symptoms of the environmental crisis i…
See United Nations Commission on Sustainable Development. …
An approach to sustainable development which involves public participation and integrates environmental, social, and economic issues into a holistic framework for analysis and management. …
Managing the use, development, and protection of natural resources in a way or at a rate which enables people and communities to provide for their social, economic, and cultural well‐being and for their health and safety. See also sustainable development. …
The use of an organism, ecosystem, or other renewable resource at a rate that is within its capacity for renewal. …
The rate at which a renewable resource may be used in a sustainable way. Traditional ways of harvesting natural renewable resources ?such as fish from the oceans, wood from the forests, and plants and products from natural ecosystems?have usually been sustainable so long as the quantities extracted were not greater than natural processes were able to replace. Many ways in which natural resources a…
A low‐lying depression on the ground surface, which is often marshy or swampy, or may contain small lakes. …
A low‐lying area of wetland that is usually at least partially flooded, is covered with grasses and trees, has better drainage than a bog, has more woody plants than a marsh, and does not accumulate deposits of peat. Swamps may be freshwater or saltwater, and tidal or non‐tidal. …
The above‐ground component of grassland vegetation, which comprises grasses and herbs. …
A thin sheet of water that moves up a beach after a wave breaks on the shore. See also surf. …
A relatively smooth ocean wave (up to two metres high and 30 metres long) that may travel great distances from its source. …
One of two or more organisms that are engaged in symbiosis. See also facultative mutualist. …
A situation in which two different species live together and interact, with one benefiting and the other either benefiting (mutualism), not being significantly affected (commensalism), or being harmed (parasitism). …
A relationship between members of two different species which results in a mutual benefit (symbiosis). …
Describing closely related species that have naturally overlapping ranges but do not interbreed. Contrast allopatric. …
A concave fold of rock strata, with the youngest rocks at the centre of the downfold. Contrast anticline. …
A complex type of fold in rock, in which there are many small folds superimposed on the major syncline. …
A collection of characteristics that occur together, such as the symptoms that are characteristic of a particular disease. …
The branch of ecology that deals with whole communities of plants and animals, and the interactions of the organisms within them. Contrast autecology. …
The combined effect of cooperative interaction between two or more changes that is greater than the sum of their separate effects. Contrast additive effect. …
The combination of two or more changes which is mutually reinforcing, making an overall impact greater than the sum of their separate effects. …
Overall, or relating to a large‐scale or broad view. …
The branch of meteorology that deals with regional‐scale weather phenomena. Contrast mesoscale meteorology. …
The ability to put things together to form a new whole, such as the development of new ideas from existing ones, or the combination of separate elements to form a new complex product, synthetic chemical compound, or material. …
Liquid or gaseous fossil fuels that are produced from coal, lignite, or other solid carbon sources. Also known as synfuel . …
Artificial (anthropogenic) organic chemicals, some of which are volatile and others of which tend to stay dissolved in water without undergoing evaporation. …
Any collection of components that work together to perform a function, such as the hardware and software that comprise a computer system, or the biotic and abiotic elements that make up an ecosystem. See also closed system, open system. …
The study of species, which includes their description (identification) and naming (taxonomy), and the study of relationships among and between taxa (phylogenetics). …
The international system of units; the metric system of measurements used in science. Some SI units and conversion are given in Appendix 10. …
Affecting or spread through the whole body (for example of a plant or animal), not localized. …
A herbicide that kills the whole of a plant, not just the part it is sprayed on. Contrast contact herbicide. …