Glossary Flashcards
Biochemical Oxygen Demand (BOD)
A measure of the amount of dissolved oxygen required to break down the organic material in a given volume of water through aerobic biological activity
Abiotic Factors
A non-living, physical factor that may influence an organism or ecosystem; for example, temperature, sunlight, pH, salinity, precipitation
Biodegradable
Capable of being broken down by natural biological processes; for example, the activities of decomposed organisms
Biodiversity
The amount of biological or living diversity per unit area. It includes the concepts of species diversity and genetic diversity
Biomass
The mass organic material in organisms or ecosystems, usually per unit area. Sometimes the term “dry weight biomass” is used where mass is measured after the removal of water. Water is not organic material and I organic material is usually relatively insignificant in terms of mass
Biome
A collection of ecosystems sharing similar climatic conditions: for example, tundra, tropical rainforest, desert
Biosphere
The paper of the earth inhabited by organisms, that is, the narrow zone (a few kilometres in thickness) in which plants and animals exist. It extends from the upper part of the atmosphere (where birds, insects and windblown pollen may be found) down to the deepest part of the Earth’s crust to which living organisms venture
Biotic Factor
A living, biological factor that may influence an organism or ecosystem; fro example, predation, parasitism, disease, competition.
Carrying Capacity
The maximum number of a species or “load” that can be sustainably supported by a given environment
Climax Community
A community of organisms that is more or less stable, and that is in equilibrium with natural environmental conditions such as climate; the end point of ecological succession.
Community
A group of populations living and interacting with each other in a common habitat
Competition
A common demand by two or more organisms upon a limited supply for a resource; food, water, light, space, mates, nesting sites. It maybe be intraspecific or interspecific
Correlation
A measure of the association between two variables. If two variables tend to move up or down together, they are said to be positively correlated. If they tend to move opposite directions, they are said to be negatively correlated
Crude Birth Rate
The number of births per thousand individuals in a population per year
Crude Death Rate
The number of deaths per thousand individuals per year
Demographic Transition
A general model describing the changing levels of fertility and mortality in a human population over time. It was developed with reference to transition experienced as developed countries (for example, those of North America, Europe, Australasia) passed through the processes of industrialisation and urbanisation
Diversity
A generic term for heterogeneity. The scientific meaning of diversity becomes clear from the context in which it is used; it may refer to heterogeneity of species or habitat, or to genetic heterogeneity
Genetic Diversity
The range of genetic material present in a gene pool or population of a species
Habitat Diversity
The range of different habitats or number of ecological a niches per unit in an ecosystem p, community or biome. Conservation of habitat diversity usually leads to the conservation of species and genetic diversity
Diversity Index
A numerical measure of species diversity that is derives from both the number of species (variety) and their proportional abundance.
Species Diversity
The variety of species per unit area. This includes both the number of species orders and their relative abundance
Doubling Time
The number of years it would take a population to double its size at it’s current growth rate. A natural increase rate of 1% will enable a human population to double in 70 years. Other doubling times can then be calculated proportionately, that is, the doubling time for any human population is equal to 70 divided by the natural increase rate.
Ecological Footprint
The real of land and water required to support a defined human population are a given standard of living. The measure takes account of the area require to provide all the resources needed by the population, and the assimilation of all wastes.
Ecosystem
A community of interdependent organism and the physical environment they inhabit
Entropy
A measure of the amount of disorder, chaos or randomness in a system; the greater the disorder, the higher the level of entropy
Environmental Impact Assessment (EIA)
A method of detailed surgery required, in many countries befriend a major development. Ideally it should be independent of, but paid for by, the developer. Such a survey should include a baseline study to measure environmental conditions before development commences, and to identify areas and species of conservation importance. The report produced is know as an environmental impact statement (EIS) or environmental management review in some countries. The monitoring should continue for some time after the development.
Equilibrium
A state if balance among the components of a system
Eutrophication
The natural or artificial enrichment of a body of water, particularly with respect to nitrates and phosphates, that results in the depletion of the oxygen content of the water. Eutrophication is accelerated by human activities that add detergents, sewage or agricultural fertilisers to bodies of water.
Evolution
The cumulative, gradual change in the genetic characteristics of successive generations of an organisms, ultimately giving rise to species or races different from the common ancestor. Evolution reflects changes in the genetic composition of a population over time.
Feedback
The return of part of the output from a system as input, so as to affect succeeding outputs
Negative Feedback
Feedback that tends to damp down, neutralise or counteract any deviation from an equilibrium, and promotes stability
Positive Feedback
Feedback that amplifies or increases change; it lead to exponential deviation away from an equilibrium
Fertility
In the context of human populations, this refers to the potential for reproduction exhibited in a population. It may be measured as fertility rate, which is the number of births per thousand women child-bearing age. Alternatively it may be measured as total fertility, which is simply the average number of children a woman has in her lifetime.
Gaia Hypothesis
Developed by James Lovelock. It compare the earth to a living organism in which feedback mechanisms maintain equilibrium.
Global Warming
An increase in the average temperature of the earths atmosphere
Gross National Product (GNP)
The current value of all goods and services in a country per year
Greenhouse Gases
Those atmospheric gases which absorb infrared radiation, causing world temperatures to be warmer than they otherwise would be. This process is sometimes known as “radiation trapping”. The natural greenhouse effect is caused mainly by water and carbon dioxide. Human activities have led to an increase in the levels of carbon dioxide, methane and nitrous oxide (dinitrogen oxide, N2O) in the atmosphere, and there are fears that this may lead to global warming.
Habitat
The environment in which a species normally lives
Halogenated Organic Gases
Usually known as halocarbons and first identified as depleting the ozone layer in the stratosphere. Now known to be potent greenhouse gases. The most well known are chlorofluorocarbons (CFC’s)
Isolation
The process by which two populations become separated by geographical, behavioural genetic or reproductive factors. If gene flow between the two subpopulations is prevented, new species may evolve.
K-Strategist
Species that usually concentrate their reproductive investment in a small number of offspring, thus increasing their survival rate and adapting them for living in long-term climax communities
Latitude
The angular distance from the equator (that is, North or South of it) as measured from the centre of the Earth (usually in degrees)
LEDC
Less economically developed country: a country with low to moderate industrialisation and low to moderate average GNP per capita
MEDC
More economically developed country: a highly industrialised country with high average GNP per capita
Model
A simplified description designed to show the structure or working of an object, system or concept
Mutualism
A relationship between individuals of two or more species in which all benefit and none suffer. (The term symbiosis will not be used)
Natural Capital
A term sometimes used by economists for natural resources that, I appropriately managed, can produce a “natural income” of of goods and services. The natural capital of a forest might provide a continuing natural income of timber, game, water and recreation
Non Renewable Natural Capital
Natural resources that cannot be replenished within a timescale of the same order as that at which point they are taken from the environment and used; for example, fossil fuels
Renewable Natural Capital
Natural resources that have a sustainable yield or harvest equal to or less than their natural productivity; for example, food crops, timber
Replenish-able natural capital
Non-living natural resources that depend on the energy of the sun for their replenishment; for example, groundwater
Rate of Natural Increase
The form in which human population growth rates are usually expressed: Inward and Outward migration is ignored
Niche
A species’ share of a habitat and the resources in it. An organism’s ecological niche depends not only on where it lives but also on what it does
Parasitism
A relationship between two species in which one species (the parasite) lives in or on another (the host), gaining all or much (in the case of a partial parasite) of its food from it
Plate Tectonics
The movement of the eight major and several minor internally rigid plates of the earths lithosphere in relation to each other and to the partially mobile asthenosphere below.
Pollution
The addition to an environment of a substance or an agent (such as heat) by human activity, at a rate greater than that at which it can be rendered harmless by the environment, and which has an appreciable effect on the organisms within it
Point Source Pollution
The release of pollutants from a single, clearly identifiable site; for example, a factory chimney or the waste disposal pipe of a factory
Non-Point Source Pollution
The release of pollutants from numerous, widely dispersed origins; for example, gases from the exhaust systems of vehicles
Population
A group of organisms of the same species living in the same area at the same time, and which are capable of interbreeding.
Gross Productivity (GP)
The total gain in energy or biomass per unit area per unit time, which could be through photosynthesis in primary producers or absorption in consumers.
Gross Primary Productivity (GPP)
The total gain in energy or biomass per unit area per unit time fixed by photosynthesis in green plants.
Gross Secondary Productivity
The total gain in consumers in energy or biomass per unit area per unit time through absorption
Net Productivity (NP)
The gain in energy or biomass per unit area per unit time remaining after allowing for respiratory losses (R). Other metabolic losses may take place, but these may be ignored when calculating and defining net productivity for the purpose of this course
Net Primary Productivity (NPP)
The gain by producers in energy or biomass per unit area per unit time remaining after allowing for respiratory losses (R). This is potentially available to consumers in an ecosystem.
Net Secondary Productivity (NSP)
The gain by consumers in energy or biomass per unit area per unit time remaining after allowing for respiratory losses (R).
Primary Productivity
The gain by producers in energy or biomass per unit area per unit time. This term could refer to either gross or net primary productivity.
Secondary Productivity
The biomass gained by heterotrophic organisms through feeding and absorption, measured in units of mass or energy per unit area per unit time.
R-Strategist
Species that tend to spread their reproductive investment among a large number of offspring so that they are well adapted to colonise new habitats rapidly and make opportunistic use of short-lived resources.
Sere
The set of communities that succeed on another over the course of succession at a given location
Smog
The term now used for any haziness in the atmosphere caused by air pollutants. Photochemical smog is produced through the effect of ultraviolet light on the products of internal combustion engines. It may contain ozone and is damaging to the human respiratory system and eyes.
Society
An arbitrary group of individuals who share some common characteristic such as geographical location, cultural background, hosted cuss timeframe, religious perspective, value system, and so on
Soil
A mixture of mineral particles and organic material that covers the land, and in which terrestrial plants grow.
Soil profile
A vertical section through a soil, from the surface down to the parent material, revealing the soil layers or horizons
Speciation
The process through which new species form
Species
A group of organisms that interbreed to produce fertile offspring
Steady-State Equilibrium
The condition of an open system in which there are no changes over the longer term, but in which there may be oscillations in the very short term. There are continuing inputs and outputs of matter and energy, but the system as a whole remains in a more or less constant state (for example, a climax ecosystem)
Succession
The orderly process of change over time in a community. Changes in the community of organisms frequently cause changes in the physical environment that allow for another community to become established and replace the former through completion. Often, but not inevitably, the later communities in such a sequence or sere are more complex than those that appear earlier
Sustainability
Use of global resources at a rate that allow natural regeneration and minimises damage to the environment. For example, as system of harvesting renewable resources at a rate that will be replaced by natural growth might be considered to demonstrate sustainability
System
An assemblage of parts and the relationships between them, which together constitute an entity or whole
Closed System
A system in which energy, but not matter, is exchanged with its surroundings
Isolated System
A system that exchanges neither matter nor energy with its surroundings
Open System
A system in which both matter and energy are exchanged with its surroundings (for example, natural ecosystems)
Tropic level
The position that an organism occupies in a food chain, or a group of organisms in a community that occupy the same position in food chains
Zonation
The arrangement of patterning of plant communities or ecosystems into parallel or sub-parallel bands in response to change, over a distance, in some environmental factor. The main biomes display zonation in relation to latitude and climate. Plant communities may also display zonation with altitude on a mountain, or around the edge of a pond in relation to soil moisture
Technocentric
Values centred on technology, problem can be solved using science and technological advancement. They suggest that humans have control over nature due to this
Ecocentric
The earth isn’t exclusively for one species it’s for all, work with the earth and its limited resources. The idea that we need the earth much more than it needs us, so protecting and conserving it is crucial to us.
