C4.2 Nutrient Cycling

Define Primary Production

The biomass produced by autotrophs

When carbon is fixed through photosynthesis

Define Secondary Production

The accumulation of Biomass by heterotrophs

When they assimilate carbon compound from food

Define carbon sink and give an example

An Organism or system that absorbs and stores more than it releases

Ex: Plants that photosynthesize more than they require

Define carbon source and give an example

An organism or system that releases more carbon dioxide than it absorbs

Ex: Herbivores and carnivores release Co2 through respiration

State the processes which move carbon through ecosystems

• Photosynthesis

• Feeding Respiration

• Decomposition

Describe Combustion

The release of carbon dioxide by burning organic matter or combustion fuels

Describe and explain the long term trend depicted in the keeling curve

It tracks atmospheric carbon dioxide levels

State the source of atmospheric oxygen

Photosynthesis increases atmospheric oxygen, enabling the evolution of aerobic respiration

List elements required by living organisms that must be cycled through ecosystems

• Hydrogen

• Oxygen

• Iron

• Potassium

• Phosphorus