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Glossary

To assist those interested in working on environmental issues in the E&E region, we are providing the following glossary of ecological and geological terms. The information contained here is expected to change over time as additional definitions are added.

If you have additions and/or corrections please contact: Webmaster

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Abiotic - The physical, or abiotic, part of the environment includes the temperature, moisture, light, altitude and chemical interactions affecting the habitat, the availability of essential nutrients, and the level of oxygen and carbon dioxide. These abiotic features limit the types of organisms which are present in the habitat.

Acidification - the lowering of soil and water pH due to acid precipitation and deposition usually through precipitation; this process disrupts ecosystem nutrient flows and may kill freshwater fish and plants dependent on more neutral or alkaline conditions (see acid rain).

Acid rain - characterized as containing harmful levels of sulfur dioxide or nitrogen oxide; acid rain is damaging and potentially deadly to the earth's fragile ecosystems; acidity is measured using the pH scale where 7 is neutral, values greater than 7 are considered alkaline, and values below 5.6 are considered acid precipitation; note: a pH of 2.4 (the acidity of vinegar) has been measured in rainfall in New England.

Adaptation - The adjustments that organisms make to become better suited to their environment.

Adaptive radiation - the evolution of a single ancestor species into several new species within a relatively short period of time and in a certain geographic area. The plants and animals of the Galápagos Islands are a result of adaptive radiation, where one plant or one animal species diversified into many species that fill a variety of ecological roles. For example, more than a dozen species of finches evolved from a single founding species that colonized the islands from the mainland of South America. (WWF)

Aerosol - a collection of airborne particles dispersed in a gas, smoke, or fog.

Afforestation - converting a bare or agricultural space by planting trees and plants; reforestation involves replanting trees on areas that have been cut or destroyed by fire.

Alluvial - Pertaining to material or processes associated with transportation and or subaerial deposition by concentrated running water.

Alluvium - Unconsolidated clastic material subaerially deposited by running water, including gravel, sand, silt, clay, and various mixtures of these.

Atmosphere - The layer of gases, also called air, surrounding the earth. The air consists of a mixture of gases: 78 percent nitrogen, 21 percent oxygen, and .02 percent carbon dioxide.

Arid, semi-arid and dry sub-humid areas - Areas, other than polar and sub-polar regions, in which the ratio of annual precipitation to potential evapotranspiration falls within the range from 0.05 to 0.65.

Autotrophs - Organisms which make organic materials from inorganic substances by means of energy coming from outside the organism. Autotrophs is a term applied to some bacteria and plants with chlorophyll.

Aquatic - living or growing in water. (NPS)

Asbestos - a naturally occurring soft fibrous mineral commonly used in fireproofing materials and considered to be highly carcinogenic in particulate form.

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Backslope - The hillslope profile position that forms the steepest and generally linear, middle portion of the slope.

Bar - A generic term for any of various elongate offshore ridges, banks, or mounds of sand, gravel, or other unconsolidated material submerged or built up by the action of waves or currents.

Beach Ridge - A low, essentially continuous mound of beach or beach-and-dune material heaped up by the action of waves and currents on the backshore of a beach, which is beyond the present limit of storm waves. These ridges roughly parallel the relict or present shoreline.

Bedrock - A general term for the solid rock that underlies the soil and other unconsolidated material or that is exposed at the surface.

Biodiversity - 1. "the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems" (Convention on Biological Diversity, 1992).

2. "The sum total of all life on Earth, that wealth of species, ecosystems, and ecological processes that makes our living planet what it is. It is our living resource base, our biological capital in the global bank, and what distinguishes it perhaps more than anything else is the fact that its loss is an irreversible process. Once a species of plant or animal goes extinct, it will never be seen again, and we now face not just the loss of individual species, but the loss of entire biotic communities, entire ecosystems, upon which we ourselves ultimately depend for our own survival." (Hotspots: Earth's Biologically Richest and Most Endangered Terrestrial Eco-regions, 2000).

Biogeography - the study of living systems and their distribution. Biogeography is important to the study of the Earth's biodiversity because it helps with understanding where animals and plants live, where they don't, and why. (WWF)

Bio-indicators - a plant or animal species whose presence, abundance, and health reveal the general condition of its habitat.

Biomass - the total weight or volume of living matter in a given area or volume.

Bio-prospecting - Collection and analysis of small numbers or amounts of organisms to detect bioactive compounds that may have commercial value, often in the pharmaceutical industry.

Biological resources - includes genetic resources, organisms or parts thereof, populations, or any other biotic component of ecosystems with actual or potential use or value for humanity.

Biosphere - The part of the earth in which living species are found is called the biosphere. Most organisms are found within a few meters of the earth's surface, either in the soil, water, or atmosphere.

Biotechnology - means any technological application that uses biological systems, living organisms, or derivatives thereof, to make or modify products or processes for specific use.

Biotic - refers to the living components of the environment (such as plants, animals, and fungi) that affect ecological functions. (WWF)

Boreal - pertaining to the north (WWF)

Brackish - Slightly salty or briny water. Brackish water is saltier than fresh water but less salty than seawater (WWF)

Buffer - Vegetation strip maintained along a stream, lake, road, or different vegetative zone to mitigate the impacts of actions on adjacent lands. Also called a buffer strip.

Bycatch - fishes, or any other animals, that are accidentally caught in fishing gear (WWF)

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Carr - Wetland on organic soil with greater than 25% cover of shrubs. Typically, carrs are dominated by willows (Salix species). (Mitsch and Gosselink 1986)

Carbon cycle - the term used to describe the exchange of carbon (in various forms, e.g., as carbon dioxide) between the atmosphere, ocean, terrestrial biosphere, and geological deposits.

Carrying Capacity - The carrying capacity is the maximum population of an individual plant or animal species that a community can support.

Catchments - assemblages used to capture and retain rainwater and runoff; an important water management technique in areas with limited freshwater resources, such as Gibraltar.

Cellulose - The cellulose is a complex carbohydrate that is the major component of the cell walls of plants.

Chlorophyll - The green pigment of plants which converts light energy into chemical energy is called chlorophyll.

Chloroplast - Chloroplasts are the tiny, spherical bodies containing chlorophyll. They are the centre of photosynthesis in a plant.

Community - a characteristic group of plants and animals living and interacting with one another in a specific region under similar environmental conditions (WWF)

Consumers - Any organism that feeds on other plants or animals is a consumer. All consumers are directly or indirectly dependent on producers (plants) for food. Consumers are also called heterotrophs.

Corridor - Corridors can be discrete linear landscape features such as hedgerows and riparian strips, as well as broad, internally heterogeneous zones that permit dispersal of species between habitat patches, landscapes, or even regions over long periods of time. (BROWN and GIBSON 1983 in NOSS 1993)

Crossbedding - Cross-stratification in which the cross-beds are more than 1 cm in thickness.

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DDT (dichloro-diphenyl-trichloro-ethane) - a colorless, odorless insecticide that has toxic effects on most animals; the use of DDT was banned in the US in 1972.

Defoliants - chemicals which cause plants to lose their leaves artificially; often used in agricultural practices for weed control, and may have detrimental impacts on human and ecosystem health.

Deforestation - the destruction of vast areas of forest (e.g., unsustainable forestry practices, agricultural and range land clearing, and the over exploitation of wood products for use as fuel) without planting new growth.

Delta - A body of alluvium, nearly flat and fan-shaped at or near the mouth of a stream where it enters a body of relatively quiet water, usually a lake.

Depression - Any relatively sunken part of the Earth's surface, especially a low-lying area surrounded by higher ground.

Desertification - the spread of desert-like conditions in arid or semi-arid areas, due to overgrazing, loss of agriculturally productive soils, or climate change.

Drainageway - A general term for a course of channel which water moves in draining an area.

Dredging - the practice of deepening an existing waterway; also, a technique used for collecting bottom-dwelling marine organisms (e.g., shellfish) or harvesting coral, often causing significant destruction of reef and ocean-floor ecosystems.

Drift - A general term applied to all mineral material (clay, sand, silt, boulders) transported by a glacier and deposited directly by or from the ice, or by running water emanating from the glacier. Generally applies to Pleistocene glacial deposits.

Drift-net fishing - done with a net, miles in extent, that is generally anchored to a boat and left to float with the tide; often results in an over harvesting and waste of large populations of non-commercial marine species (by-catch) by its effect of "sweeping the ocean clean".

Drought - The naturally occurring phenomenon that exists when precipitation has been significantly below normal recorded levels, causing serious hydrological imbalances that adversely affect land resource production systems.

Dune, Eolian - A low mound, ridge, bank, or hill of loose, windblown, granular material (generally sand), either bare or covered by vegetation, that is capable of movement from place to place but always maintaining its characteristic shape.

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Ecology - The study of how all plants and animals interact with each other in their non-living environment.

Ecological or ecosystem services - valuable services provided by natural systems. Examples of ecological services include flood control, air purification, and climate control. (WWF)

Eco-region - 1. A geographically distinct area of land that is characterized by a distinctive climate, ecological features, and plant and animal communities. The Klamath-Siskiyou Coniferous Forests in the U.S. Pacific Northwest is an example of an ecoregion. (WWF)
2. A restricted geographic area (scale usually in hundreds of kilometers) with particular weather patterns, ocean currents and depths, drainage, and communities of plants and animals.

Ecosystem - 1. A community of plants, animals, and microorganisms that are linked by energy and nutrient flows and that interact with each other and with the physical environment. Rain forests, deserts, coral reefs, grasslands, and a rotting log are all examples of ecosystems. (WWF)
2. a dynamic complex of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit.

Ecological Niche - A style of life that is unique to a species of plant or animal. A species niche includes its place in the food chain, relationships with the other species in its habitat, habitat requirements, special adaptations to life in the ecosystem, and daily and seasonal periods of activity. Only one species can occupy a niche at a time.

Effluents - waste materials, such as smoke, sewage, or industrial waste which are released into the environment, subsequently polluting it.

Emergent Plant - A rooted herbaceous plant species that has parts extending above a water surface. (Mitsch and Gosselink 1986)

Endemic Species - Species that naturally occurs in only one area or region. Their natural distribution or range are confined by geography or morphology; often these species are rare.

Environment - All the external factors to which an organism is exposed. Includes all abiotic and biotic factors that may influence the organism.

Ephemeral - lasting for a very short time (WWF)

Estuary - an area where sea water mixes with fresh water. (NPS)

Evolution - the process of change in the traits of organisms or populations over time. Evolution, through the process of natural selection, can lead to the formation of new species. (WWF)

Ex-situ conservation - The propagation or preservation of animals or plants outside their natural habitat, involving control by humans of the species chosen to constitute a population and reproductive choices within that population (i.e. gene banks; botanical gardens).

Extinct - refers to a species that no longer exists. Local extinction occurs when every member of a particular population has died. Global extinction occurs when every member of a species has died. The passenger pigeon and the dodo are examples of globally extinct birds. (WWF)

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Fauna - the animals that live in a particular area (WWF)

Fen - A non-acidic peat-forming wetland that receives nutrients from sources other than precipitation, usually through groundwater movement. (Mitsch and Gosselink 1986)

Flagship species - Species that appeal to the public and have other features that make them suitable for communicating conservation concerns.

Floodplain - A nearly flat plain along a river or stream that is subject to flooding. (NPS)

Flora - the plants that live in a particular area (WWF)

Food Chain - A food chain describes the transfer of energy from one organism to another. Food hains begin with the sun, the source of all energy on earth. Since only plants can produce food from the sun's energy the first link in a food chain is always a plant. The second link in the chain is a plant eater and the third link a meat eater. A typical food chain might be diagrammed as: grass:---> rabbit:---> red fox

Food Pyramid - A food pyramid is a diagram that gives an estimate of the amount of energy available at each trophic or feeding level. The amount of stored energy is calculated by weighing all living things at each feeding level and the result is called a pyramid of biomass.

Food Web - A food web is a diagram which shows all the feeding relationships within a community. The diagram, which shows how the various food chains are interlinked, should nclude the scavengers, decomposers, and producers as well as the herbivores, omnivores, and carnivores.

Footslope - The hillslope position that forms the inner, gently inclined surface at the base of a hillslope.

Fragmentation of "forest, habitat or landscape" - 1. the breaking up of large habitats into smaller, isolated chunks. Fragmentation is one of the main forms of habitat destruction, which is the primary reason biodiversity is in decline. (WWF)
2. The breaking up of habitat into discrete islands through modification or conversion of habitat by management activities.

Freshwater - water with very low soluble mineral content; sources include lakes, streams, rivers, glaciers, and underground aquifers.

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Genetically-modified organisms (GMO) - 1. A GMO is an organism--plant or animal--which has had a gene from an organism spliced into it through biotechnological means. Gene splicing is a new way of doing something mankind has done since Neolithic times--modifying plants and animals. In the European Union, a GMO is strictly defined by Commission Directive 90/220 as "biological entities capable of replication or of transferring genetic material" produced through genetic modification. Products of GMOs which are not capable of replication or transferring genetic material, such as tomato paste or soybean oil, are not included in this definition.
2. see: http://ext.agn.uiuc.edu/extension/gmo/gmo1.htm

Genetic material - means any material of plant, animal, microbial or other origin containing functional units of heredity.

Genetic resources - Genetic material of actual or potential value.

Geography - the science of space and place that brings together Earth's physical and human dimensions in the integrated study of people, places, and environments (WWF)

Geomorphology - The science that treats the general configuration of the earth's surface; specifically the study of the classification, description, nature, origin, and development of landforms and their relationship to underlying structures, and of the history of geologic changes as recorded by these surface features.

Greenhouse gas - a gas that "traps" infrared radiation in the lower atmosphere causing surface warming; water vapor, carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, and ozone are the primary greenhouse gases in the Earth's atmosphere.

Global warming - the process by which the Earth's atmosphere is warming because of the release of "greenhouse gases," such as carbon dioxide. These gases are released into the air from burning gas, oil, coal, wood, and other resources and trap heat in an action similar to that of the walls of a greenhouse. (WWF)

Grasslands - areas of abundant grasses and shrubs with very few trees, like prairies or meadows. Grasslands can be found in many places. Large temperate grasslands occur naturally in central North America (prairies), southern South America (pampas), central Asia (steppes), southern Africa (savannas), and Australia. (WWF)

Greenhouse effect - the trapping of heat in the Earth's atmosphere by certain gases such as carbon dioxide, methane, and nitrous oxide. Some scientists predict that the temperature and sea level rise associated with global warming could adversely affect biodiversity. (WWF)

Groundwater - water sources found below the surface of the earth often in naturally occurring reservoirs in permeable rock strata; the source for wells and natural springs.

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Habitat - 1. The area in which an animal, plant, or microorganism lives and finds the nutrients, water, sunlight, shelter, living space, and other essentials it needs to survive. Habitat loss, which includes the destruction, degradation, and fragmentation of habitats, is the primary cause of biodiversity loss. (WWF)
2. The place or type of site where an organism or population naturally occurs.

Herbaceous - Non-woody vegetation, such as graminoids and forbs.

Heterotrophic - A heterotrophic organism cannot produce its own food. All animals are eterotrophic and obtain their food from plants.

Hot Spot - Biodiversity is not evenly distributed on the planet. Some areas harbor far greater concentrations of living creatures than others. Conservation International (CI) has identified those biologically rich areas under the greatest threat of destruction as biodiversity hotspots, and concentrates conservation in these areas to have the most impact. To date, CI has identified 25 priority hotspots based on three criteria: the number of species present, the number of those species found exclusively in an ecosystem and the degree of threat they face. (http://www.conservation.org/Hotspots/default.htm)

Horizon - A horizon is a layer of soil running more or less parallel to the soil surface. The different soil horizons are the result of the actions of living organisms on the original parent materials. Organic matter is added to the soil gradually by the plants and animals living in the soil. Over a long period of time, this organic material or humus builds up. The largest amounts of organic material are near the surface in what is known as the topsoil. Below the topsoil is the subsoil which contains many of the nutrients washed out of the topsoil by rain. The final layer contains the parent material but no humus.

Humus - Humus is decaying organic matter such as dead plants, leaf litter and the remains of dead animals in an advanced state of decomposition. Humus is usually dark in colour and rich in nitrogen.

Hydrology - The science dealing with the properties, distribution, and circulationof water. (Mitsch and Gosselink 1986)

Hydrophytic Vegetation - Plant life growing in water or on a substrate that is at least potentially deficient in oxygen as a result of excessive water content. (Mitsch and Gosselink 1986)

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Indicator species - A species whose status provides information on the overall condition of the ecosystem and of other species in that ecosystem; taxa that are sensitive to environmental conditions and which can therefore be used to assess environmental quality.

Invasive species - Species that damage the ecosystem into which they are introduced by occupying niches of native species and out competing them for resources such as food and space.

In-situ conditions - conditions where genetic resources exist within ecosystems and natural habitats, and, in the case of domesticated or cultivated species, in the surroundings where they have developed their distinctive properties.

In-situ conservation - 1. The conservation of biodiversity within the evolutionary dynamic ecosystems of the original habitat or natural environment.
2. The conservation of ecosystems and natural habitats and the maintenance and recovery of viable populations of species in their natural surroundings and, in the case of domesticated or cultivated species, in the surroundings where they have developed their distinctive properties.

Introduced Species - a species that does not naturally occur in an area. Also called alien, exotic, or non-native species, these invaders can cause major problems for native plants and animals. (WWF)
2. Species that are not native to an area but brought in through human activities.

Island Effect - the study of biodiversity on an island or fragmented landmass. Genetic and species diversity is limited upon the rate of immigration and emigration from the area as dependent upon its distance to other habitats.

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Kame - A low mound, knob, hummock, or short irregular ridge, composed of stratified sand and gravel deposited by a subglacial stream as a fan or delta at the margin of a melting glacier; or as a ponded deposit on the surface or at the margin of stagnant ice; or by a supraglacial stream in a low place or hole on the surface of the glacier.

Kettle - A steep-sided, bowl-shaped depression commonly without surface drainage; usually formed by a large detached block of stagnant ice that had been partially or wholly buried in the drift.

Keystone Species - A species whose loss from an ecosystem would cause a greater than average change in other species populations or ecosystem processes; whose continued well-being is vital for the functioning of a whole community, such as the herring in the North Atlantic or krill in Antarctica.

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Lacustrine deposit - Clastic sediment and chemical precipitates deposited in lakes.

Lakebed - The flat to gently undulating ground underlain or composed of fine-grained sediment deposited in a former lake.

Lake plain - A nearly level surface marking the floor of an extinct lake filled with wellsorted generally fine-textured sediments that are commonly stratified.

Landform - Any physical, recognizable form or feature on the earth's surface, having a characteristic shape and range in composition, and produced by natural causes.

Limestone - A sedimentary rock consisting chiefly of calcium carbonate, primarily in the form of calcite.

Loess - Material transported and deposited by wind and consisting primarily of silt size particles.

Longshore bar - A narrow, elongate, coarse-textured ridge that once rose near to, or barely above, a pluvial or glacial lake and extending generally parallel to the shore.

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Marsh - A frequently or continually inundated wetland, often developing in shallow ponds, depressions, and river margins. Marshes are dominated by herbaceous plants, such as grasses (e.g., Phragmites), sedges, cattails (e.g.,Typha), and bulrushes (e.g.Scirpus). Waters are usually neutral to basic. (Mitsch and Gosselink 1986)

Mico-high - A generic microrelief term applied to slightly elevated areas relative to the adjacent ground surface; changes in relief range from several centimeters to several meters.

Mico-low - A generic microrelief term applied to slightly depressed areas relative to the adjacent ground surface; changes in relief range from several centimeters to several meters.

Microrelief - Slight variations in the height of a land surface that are too small to delineate on a topographic or soil map; Applies to local and slight irregularities in the land surface.

Migration - the movement of animals in response to seasonal changes or changes in the food supply. Examples of animals that migrate include ruby-throated hummingbirds, salmon, monarch butterflies, buffalo, and elephants. (WWF)

Monadock - An isolated hill or mountain of resistant rock rising conspicuously above the general level of a lower erosion surface in a temperate climate representing an isolated remnant of a former erosional cycle in an area that has been beveled to its base level.

Moraine, End - A ridge-like accumulation that is being or was produced at the outer margin of an actively flowing glacier at any given time.

Moraine, Ground - An extensive, fairly even layer of till, having an uneven or undulating surface; a deposit of rock and mineral debris dragged along, in, on, or beneath a glacier and emplaced by process including basal lodgement.

Moraine, Kame - An end moraine that contains numerous kames.

Moraine, Lateral - A ridge-like moraine carried on and deposited at the side margin of a valley glacier.

Moraine, Recessional - An end or lateral moraine, built during a temporary but significant halt in the final retreat of a glacier.

Moraine, Terminal - An end moraine that marks the farthest advance of a glacier and usually has the form of a massive arcuate or concentric ridge or complex of ridges, underlain by till and other types of drift.

Montane - pertaining to a mountainous region (WWF)

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Native species - a species that occurs naturally in an area or habitat. Also called indigenous species. (WWF)

Natural Levee - A long, broad low ridge or embankment of sand and coarse silt, built by a stream on its flood plain and along both sides of its channel, especially in time of flood when water overflowing the normal banks is forced to deposit the coarsest part of its load.

Natural selection - the process by which genetic traits are passed on to each successive generation. Over time, natural selection helps species become better adapted to their environment. Also known as "survival of the fittest," natural selection is the driving force behind the process of evolution. (WWF)

Niche - the limits, for all important environmental features, within which individuals of a species can survive, grow and reproduce.

Nitrogen Cycle - Plants can use nitrogen only after it has been converted into a nitrate. Nitrogenfixing bacteria in the soil and on the nodes on the roots of plants such as clover and beans are able to form these nitrates. The nitrates are absorbed in water by the roots and used by the plants to build plant tissue. Animals receive nitrogen by eating plants. When plants or animals die, bacteria and fungi return the nitrogen compounds back into the soil. Other bacteria break down these compounds and release free nitrogen back into the atmosphere.

Noxious substances - injurious, very harmful to living beings.

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Omnivore - Omnivores are animals that eat plants and other animals.

Organism - An organism is a living creature such as a plant or animal. See also life processes.

Outwash - Stratified detritus (chiefly sand and gravel) removed or washed out from a glacier by melt-water streams and deposited in front or beyond the end moraine or the margin of an active glacier.

Outwash plain - An extensive lowland area of coarse textured, glaciofluvial material.

Overgrazing - the grazing of animals on plant material faster than it can naturally regrow leading to the permanent loss of plant cover, a common effect of too many animals grazing limited range land.

Ozone shield - a layer of the atmosphere composed of ozone gas (O3) that resides approximately 25 miles above the Earth's surface and absorbs solar ultraviolet radiation that can be harmful to living organisms.

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Pesticides - chemicals that kill or inhibit the growth of organisms that people consider undesirable. Fungicides (which kill fungi), herbicides (which kill plants), and insecticides (which kill insects) are types of pesticides. (WWF)

Phosphorus Cycle - Phosphorus is mainly found in phosphorous rocks. As a result of erosion caused by rainfall and runoff water, the phosphorus is dissolved in the water. Then these phosphorous compounds are absorbed by plants through their roots and used to build plant tissue. When animals eat plants, the phosphorus is passed on to them. Phosphorus is returned to the soil in animal droppings and in the remains of plants and animals. The organic forms of phosphorus are converted back into inorganic phosphorus by bacteria.

Photosynthesis - Photosynthesis is the chemical process during which green plants convert light energy, carbon dioxide and water in the presence of chlorophyll into carbohydrates. Oxygen is produced as a by-product.

Phytoplankton - the plant plankton and primary producers in aquatic ecosystems (WWF)

Pioneer plant - a plant species that appears early in the cycle of vegetation succession. These pioneer plants have characteristics that particularly suit their role in the early stages of succession, such as a rapid growth rate and the ability to produce large amounts of small, easily dispersed seeds. (WWF)

Poaching - the illegal killing of animals or fish, a great concern with respect to endangered or threatened.

Pollution - the contamination of a healthy environment by man-made waste.

Population - The number of organisms of the same species that are living and breeding together in the same area at the same time is called a population.

Pond - Bodies of water encircled by wetland vegetation. Wave action is minimal, allowing emergent vegetation to establish. (Mitsch and Gosselink 1986)

Potable water - water that is drinkable, safe to be consumed.

Pothole - A depressional wetland community caused by glaciation and is common to portions of the Northern Great Plains. The body of water is less than 8 ha (20 acres) in size. (Mitsch and Gosselink 1986)

Protected area - means a geographically defined area which is designated or regulated and managed to achieve specific conservation objectives.

Producer - Plants contain chlorophyll, which allows them to manufacture food though the process of photosynthesis. Only plants can make or produce their own food and therefore are called producers. Producers are also called autotrophs which means self-feeders.

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Red Book (or IUCN Red List of Threatened Species) - the IUCN (The World Conservation Union) maintains a database known as the Red Data Book. This database is the most comprehensive record for the conservation status of species around the world. Conservation categories include: (E) Endangered; (V) vulnerable; (R) rare; (I) indeterminate; and (?) suspected/unknown. E: Endangered species are in danger of extinction unless immediate action is taken to curb the destruction of the species habitat or exploitation by man. V: Vulnerable species are likely to become endangered in the near future unless measures are taken for its preservation. R: Rare species are neither endangered nor vulnerable at present but whose population is low and/or distribution limited. I: Indeterminate species means insufficient information is available, but factors dictate they are certain to be in one of the above categories. ?: Suspected but not definitely known to fall into one of the above categories.

Range - the area in which an organism may travel in its lifetime. Range also refers to the geographic distribution of a particular species. (WWF)

Realm - a region of the Earth that harbors similar groups of species based on a shared bio-geographical history. For example, while primates are found in many parts of the world, all monkeys found with prehensile tails are only found in the Neotropic realm. The Earth is made up of eight realms. (WWF)

Reintroduce - to return members of a species to their historical range. This strategy is sometimes used when a species has become locally extinct or if its population is threatened. (WWF)

Relict species - a species that has survived while other related ones have become extinct. A relict species may be one that had a wider range but is now found only in particular areas (like the European white elm tree in western Siberia), or it may have survived relatively unchanged from an older period when other kinds of species went extinct (such as horseshoe crabs). (WWF)

Restoration - the repair of ecological damage to an ecosystem so that it is close to the natural condition prior to a disturbance and it can function as a normal self-regulating system. This is done through processes such as chemical cleanups, re-vegetation, and the reintroduction of native species. (WWF)

Riparian - 1. adj. Of, on, or relating to the banks of a natural course of water (Latin riparius, from ripa, bank). (Mitsch and Gosselink 1986)
2. Pertaining to the banks of a river or other body of fresh water (WWF)
3. Lands, including wetlands, adjacent to creeks, streams, or rivers where the vegetation is strongly influenced by the presence of water. (NPS)

Riparian zone - A geographically delineated portion of the riparian ecosystem based on management concerns. (Mitsch and Gosselink 1986)

Riparian or Wetland Ecosystem - The ecosystem located between aquatic and terrestrial environments. Identified by hydric soil characteristics and riparian or wetland plant species that requires or tolerates free water conditions of varying duration. (Mitsch and Gosselink 1986)

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Salination - the process through which fresh (drinkable) water becomes salt (undrinkable) water; hence, desalination is the reverse process; also involves the accumulation of salts in topsoil caused by evaporation of excessive irrigation water, a process that can eventually render soil incapable of supporting crops.

Savanna - a type of grassland with widely spaced trees and a blanket of grasses that require a lot of light. Rainfall usually occurs in the warmer, summer months with a dry period of between two to eight months. Fires are typical across savannas during drier months and occur at intervals from one to 50 years. (WWF)

Siltation - occurs when water channels and reservoirs become clotted with silt and mud, a side effect of deforestation and soil erosion.

Slash and burn agriculture - an agricultural system in which farmers periodically clear land for farming by cutting and burning patches of forest. Traditionally, patches used for agriculture were allowed to revert to forests for a number of years before being replanted, causing minimal impact. Today, however, intensive slash and burn agriculture damages many tropical forest ecosystems. (WWF)

Soil degradation - damage to the land's productive capacity because of poor agricultural practices such as the excessive use of pesticides or fertilizers, soil compaction from heavy equipment, or erosion of topsoil, eventually resulting in reduced ability to produce agricultural products.

Soil erosion - the removal of soil by the action of water or wind, compounded by poor agricultural practices, deforestation, overgrazing, and desertification.

Specialist species - a species that has a narrow ecological niche. For example, they may be able to live in only one type of habitat, tolerate only specific environmental conditions, or eat only a few types of food. The panda is a specialist species because over 95 percent of its diet consists only of bamboo. (WWF)

Speciation - the process by which one or more populations of a species become genetically different enough to form a new species. The process often requires populations to be isolated for a long period of time. (WWF)

Species - 1. A group of organisms that have a unique set of characteristics (like body shape and behavior) that distinguishes them from other organisms. If they reproduce, individuals within the same species can produce fertile offspring.
2. The basic unit of biological classification. Scientists refer to species using both their genus and species name. The house cat, for example, is called Felis catus. (WWF)

Species richness - the number of species present in a community.

Stratified - Formed, arranged, or laid down in layers. The term refers to geologic deposits.

Stream Terrace - One of a series of platforms in a stream valley, flanking and more or less parallel to the stream channel, originally formed near the level of the stream, and representing the dissected remnants of an abandoned flood plain, stream bed, or valley floor produced during a former state of erosion or deposition.

Succession - Succession is the gradual replacement of one plant community by another plant community as a result of changes in the environment. The process of succession results from changes in the climate, and from fires, earthquakes, wind storms, floods, and human activities. Changes are also made by the community's previous organisms, which make the habitat suitable to a new plant community.

Summit - The topographically highest hillslope position of a hillslope profile and exhibiting a nearly level surface.

Sustainable - meeting the needs of the present without diminishing the ability of people, other species, or future generations to survive. (WWF)

Sustainable Development - Development policies that meet the needs of the present without compromising the ability of future generations to meet their own.

Sustainable use - means the use of components of biological diversity in a way and at a rate that does not lead to the long-term decline of biological diversity, thereby maintaining its potential to meet the needs and aspirations of present and future generations.

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Taiga - a type of coniferous evergreen forest, found in the subarctic areas of North America and Eurasia. Also known as a boreal forest (WWF)

Temperate rain forest - a type of forest found in only a few places around the world, such as the Pacific temperate rain forest on the west coast of North America. Conifer trees adapted to wet climates and cool temperatures often dominate these forests. (WWF)

Tidal Wetlands - Wetlands in which the water level fluctuates with the tide. (NPS)

Till - Dominantly unsorted and unstratified drift, generally unconsolidated deposited directly by and underneath a glacier without subsequent reworking by meltwater, and consisting of a hetergeneous mixture of clay, silt, sand, gravel, stones, and boulders.

Till, Ablation - A general term for loose, relatively permeable material deposited by the downwasting of nearly static glacier ice.

Till, Basal - Unconsolidated material of mixed composition deposited at the base of a glacier. Types of basal till include: lodgement, meltout, and flow till.

Till, Lodgement - A basal till commonly characterized by compact, fissile (platy) structure and containing rock fragments oriented with their long axes generally parallel to the direction of ice movement.

Till, Melt-Out - Till derived from slow melting of debris-rich stagnant ice buried beneath sufficient overburden to inhibit deformation under gravity, thus preserving structures derived from the parent ice.

Till Plain - An extensive flat to undulating surface underlain by till.

Toeslope - The hillslope position that forms the gently inclined surface at the base of a hillslope.

Topography - The relative position and elevations of the natural or manmade features of an area that describe the configuration of its surface.

Transpiration - Excess water is given off by the plant as water vapor through the leaf's pores. This process is called transpiration.

Traverse Dune - A very asymmetric sand dune elongated perpendicular to the prevailing wind direction, having a gentle windward slope and a steep leeward slope standing at or near the angle of repose of sand.

Tread - The flat or gently sloping surface of natural step-like landforms, commonly one of a series, such as successive stream terraces.

Trophic Level - The species position in a food chain is called the trophic level. It provides the level occupied by the species in the process of energy transfer through the ecosystem.

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Ultraviolet (UV) radiation - a portion of the electromagnetic energy emitted by the sun and naturally filtered in the upper atmosphere by the ozone layer; UV radiation can be harmful to living organisms and has been linked to increasing rates of skin cancer in humans.

Upland - A general term for the higher ground of a region, in contrast with valley, plain, or other lower lying adjacent land.

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Valley Train - A long narrow body of outwash confined within a valley beyond a glacier.

Varve - A sedimentary layer, lamina, or sequence of laminae, deposited in a body of still water within a period of 1 year; specifically, a thin pair of graded glaciolacustrine layers seasonally deposited, usually in glacial lakes or meltwater streams.

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Water Cycle - An ecosystem reuses water through the water cycle. Water enters the atmosphere as vapour from bodies of water and from the soil. Plants lose water through the pores in their leaves. Water vapour in the atmosphere condenses and forms clouds. The water droplets return to the earth as rain, snow, sleet, or hail and are used again by plants and animals and the cycle continues.

Wetlands - 1. Areas that under normal circumstances have hydrophytic vegetation, hydric soils, and wetland hydrology. It includes landscape unit such as bogs, fens, carrs, marshes, and lowlands covered with shallow, and sometimes ephemeral or intermittent waters. Wetlands are also potholes, sloughs, wet meadows, riparian zones, overflow areas, and shallow lakes and ponds having submerged and emergent vegetation. Permanent waters of streams and water deeper than 3 m (approx. 10 ft.) in lakes and reservoirs are not considered wetlands. (Mitsch and Gosselink 1986)
2. Areas that, at least periodically, have waterlogged soils or are covered with a relatively shallow layer of water. Bogs, freshwater and saltwater marshes, and freshwater and saltwater swamps are examples of wetlands. (WWF)

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