Change in Ecosystems

Question 1

Mangrove

Answer 1

Ecosystem in tropical and subtropical coastlines of quite tidal waves.

Question 2

Latitudinal Zonation

Answer 2

Changes in plant community structure due to climatic conditions associated with latitude.

Question 3

Altitudinal Zonation

Answer 3

Bands of vegetation communities showing adaptations to particular environmental conditions associated with altitude.

Question 4

Sere

Answer 4

An intermediate community found in ecological succession in an ecosystem advancing towards its climax community.

Question 5

Primary Succession

Answer 5

Development and change in plant communities over time, leading eventually from bare ground to climax community.

Question 6

Pioneer Species

Answer 6

Species of plants that colonise bare ground.

Question 7

Microenvironment

Answer 7

An area within a general habitat with specialised environmental conditions, e.g. a hollow log.

Question 8

Dominant Species

Answer 8

The most common species in a community.

Question 9

Climax Community

Answer 9

A more or less stable plant community.

Question 10

Primary Forest

Answer 10

Climax forest formed as a result of primary succession.

Question 11

Secondary Succession

Answer 11

Successive, natural changes in plant communities in an area where a previous community has been removed.

Question 12

Secondary Forest

Answer 12

Climax forest formed due to secondary succession.

Question 13

Disclimax Community

Answer 13

Final community formed after succession as a result of degrading environmental factors.

Question 14

Desertification

Answer 14

Formation of desert conditions, usually resulting from overgrazing of susceptible areas.

Question 15

Habitat Fragmentation

Answer 15

The division of a habitat into smaller, isolated portions as a result of human activities in the intervening spaces.

Question 16

Eutrophication

Answer 16

Build-up of nutrients in water; may result in oxygen depletion.

Question 17

Biological Oxygen Demand (BOD)

Answer 17

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.

Question 18

Exotic

Answer 18

Describes organisms not naturally occuring in a particular region.

Question 19

Pest

Answer 19

An organism that causes direct or indirect harm to humans or their resources; an organism in the ‘wrong’ place.

Question 20

Biodegradable

Answer 20

Able to be broken down by organisms.

Question 21

Biological Magnification

Answer 21

Concentration of substances within the tissues of organisms as they pass along a food chain.

Question 22

Half-Life

Answer 22

The time taken for a quantity, for example of a radioactive isotope or a chemical, to break down to half its original value.

Question 23

Persistence

Answer 23

Length of time a measurable chemical residue remains in the environment.

Question 24

Primary Pollutant

Answer 24

Substance that has a direct adverse effect upon the environment.

Question 25

Secondary Pollutant

Answer 25

A pollutant formed as a result of the interaction between wastes and the environment.

Question 26

Photochemical Smog

Answer 26

Secondary pollutant produced by chemical reaction between nitrogen oxides and hydrocarbons in the presence of sunlight.

Question 27

Temperature Inversion

Answer 27

Trapping of a cooler layer of air in the atmosphere under a warm layer, preventing the dispersal of heat and other pollutants.

Question 28

Microclimate

Answer 28

Climate of a very small or restricted area, especially when this differs from the climate of the surrounding area.