APES/IBESS Matter/Energy and Productivity

Photosynthesis (equation)

6CO(2) + 6H(2)O + Energy --> C(6)H(12)O(6) + 6O(2)

Respiration (equation)

C6H12O6 + 6O(2) -----> 6CO(2) + 6H(2)O + energy

Autotrophs

An organism capable of creating its own energy via photosynthesis.

Heterotrophs

An organism that is incapable of producing its own food, and is dependent on complex organic material for nutrition.

Detrivores

An organism that consumes dead organisms.

Saprotrophs

Decomposers. Heterotrophs that break down dead organic material and use the decomposition products to supply themselves with energy.

Trophic levels (terms)

Each level in a food chain. Example: all producers on the 1st trophic level, herbivores on the second and so on.

Food Chain

A series of organisms each dependent on the next as a source of food.

Food Web

A system of interlocking and interdependent food chains.

Pyramid of energy

An ecological pyramid that represents the relative energy value at each trophic level.

Pyramid of numbers

An ecological pyramid that shows the relative numbers of organisms found at each trophic level.

Pyramid of biomass

An ecological pyramid that shows the amount of organic material at each trophic level.

Productivity

Measures the energy flow in systems.

Gross primary productivity

The total amount of solar energy that producers in an ecosystem capture via photosynthesis over a given amount of time.

Net primary productivity

The energy captured by producers in an ecosystem minus the energy producers respire (what can be passed to the herbivores).

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.

Decomposer

An organism that breaks down wastes and dead organisms and returns nutrients to the abiotic