C

Question 1

C3 pathway

Answer 1

The conventional PS pathway in which carbon dioxide is fixed directly into a sugar. The initial sugar compound has just 3 carbon atoms.

Question 2

C4 pathway

Answer 2

Alternative PS pathway using enzyme PEP carboxylase which is more efficient at scavenging carbon dioxide than the enzyme in the C3 pathway. Carbon is fixed to maltic acid which has 4 carbon atoms. Maltic acid is transported to PS cells.

Question 3

Canopy exchange

Answer 3

Two way movement of material between leaves and the wider environment, either through leaching by rainwater or absorption of nutrients dissolved from dust etc that is deposited on leaves.

Question 4

Carrying capacity K

Answer 4

The maximum density of individuals that can be supported by a given level of resources.

Question 5

Catastrophic curve

Answer 5

Graphical representation of the relationship between two variables that can have two alternate states.

Question 6

Chaos

Answer 6

Situation where pop density (or some other variable) fluctuated in an apparently unpredictable way, even though the dynamics are described by a predictable equation. This is a contrast to a truely random process. Chaos may occur when density dependence is coupled with high rates of pop increase.

Question 7

Charophytes

Answer 7

Green algae, superficially resembling horsetail ferns.

Question 8

Chelates

Answer 8

Organic molecules that can bind to metal ions.

Question 9

Chemoautotroph

Answer 9

Organism that uses energy derived from the oxidation of inorganic chemicals, rather than from light, to synthesis organic compounds.

Question 10

Closed nutrient cycle

Answer 10

A cycle in which nutrients are held tightly within an ecosystem, lading to an efficient nutrient cycle.

Question 11

Closed systems

Answer 11

Systems that do not exchange material or energy with other systems. Few systems are closed, those that only exchange small fluxes are ‘relatively closed’.

Question 12

Coarse woody debris

Answer 12

The largest organic matter size fraction, consisting of large pieces of wood, not normally considered part of the forest floor litter.

Question 13

Commensalism

Answer 13

Associate between two organisms of different species form which one species gains and advantage and the other has neutral effect.

Question 14

Comminution

Answer 14

Process whereby litter is broken down into small particles.

Question 15

Condition

Answer 15

Describes an aspect of the environment that affects the functioning of an organism, but which is not consumed by it. Such as temp, soil ph, wind speed. Contrasts with resource.

Question 16

Convection

Answer 16

Vertical mixing driven by density contrasts. In the atmosphere it is usually the result of local heating.

Question 17

Conditioning

Answer 17

Process that makes litter playable to detritivores.

Question 18

Coupled

Answer 18

Describes the extent to which the properties of the bulk atmosphere affect the rate of water loss from a canopy. The decoupling effect Ω describes where a canopy is well coupled to the atmosphere (Ω near zero) in which case the boundary conductance is high, or poorly coupled (Ω near 1) with low boundary conductance.

Question 19

Crassulacean acid metabolism CAM

Answer 19

Alternative PS pathway by many succulent species to overcome water limitation. Carbon dioxide is taken up at night, rather than during the day. Fixes carbon as maltic acid like the C4 pathway and stores overnight; being rereleased and fixed as a sugar in the day by RUBISCO.

Question 20

Cross scale effects

Answer 20

The view that functional redundancy acting across different spatial scales is a significant factor in increasing the resilience of ecosystems.

Question 21

Crown fires

Answer 21

The hottest and more devastating fires that move along the top of the vegetation and spread down to soil level.

Question 22

Cuticle

Answer 22

The outer layer of a leaf that is composed of waxes, secreted by the epidermal cells.

Question 23

Cyanobacteria

Answer 23

Group of PS bacteria that contains versions of chlorophyll, giving them a blue green colour; unlike green plants they can sometimes fix nitrogen.

Question 24

Cyprinid

Answer 24

Soft-finned, mainly freshwater fishes typically with toothless jaws such as A. Brama; family includes many benthic feeders, grazers and plankton feeders.