Change in Ecosystems Flashcards
Mangrove
Ecosystem in tropical and subtropical coastlines of quite tidal waves.
Latitudinal Zonation
Changes in plant community structure due to climatic conditions associated with latitude.
Altitudinal Zonation
Bands of vegetation communities showing adaptations to particular environmental conditions associated with altitude.
Sere
An intermediate community found in ecological succession in an ecosystem advancing towards its climax community.
Primary Succession
Development and change in plant communities over time, leading eventually from bare ground to climax community.
Pioneer Species
Species of plants that colonise bare ground.
Microenvironment
An area within a general habitat with specialised environmental conditions, e.g. a hollow log.
Dominant Species
The most common species in a community.
Climax Community
A more or less stable plant community.
Primary Forest
Climax forest formed as a result of primary succession.
Secondary Succession
Successive, natural changes in plant communities in an area where a previous community has been removed.
Secondary Forest
Climax forest formed due to secondary succession.
Disclimax Community
Final community formed after succession as a result of degrading environmental factors.
Desertification
Formation of desert conditions, usually resulting from overgrazing of susceptible areas.
Habitat Fragmentation
The division of a habitat into smaller, isolated portions as a result of human activities in the intervening spaces.
Eutrophication
Build-up of nutrients in water; may result in oxygen depletion.
Biological Oxygen Demand (BOD)
A measure of the quantity of oxygen used by microorganisms (e.g., aerobic bacteria) in the oxidation of organic matter in aquatic environments; the higher the BOD, the less oxygen is available for other organisms.
Exotic
Describes organisms not naturally occuring in a particular region.
Pest
An organism that causes direct or indirect harm to humans or their resources; an organism in the ‘wrong’ place.
Biodegradable
Able to be broken down by organisms.
Biological Magnification
Concentration of substances within the tissues of organisms as they pass along a food chain.
Half-Life
The time taken for a quantity, for example of a radioactive isotope or a chemical, to break down to half its original value.
Persistence
Length of time a measurable chemical residue remains in the environment.
Primary Pollutant
Substance that has a direct adverse effect upon the environment.
