Nutrient Cycling and Energy Transfer

Flashcards covering nutrient cycles and energy transfer in ecosystems.

What happens to nutrients in an ecosystem?

Nutrients cycle; their location changes, but they never truly leave the ecosystem.

Name the major nutrients that cycle within ecosystems.

Water, carbon (as CO2), nitrogen, and phosphorus.

What organisms are responsible for nitrogen fixation?

Bacteria

What is a trophic pyramid?

Also known as a productivity pyramid, it illustrates energy transfer between feeding or trophic levels.

What percentage of solar energy is absorbed by primary producers?

A small fraction

What percentage of energy is transferred between trophic levels?

Approximately 20% (with 80% used and released)

What happens to most of the energy at each trophic level?

80% is used and released (often as heat).

Approximately what percentage of energy is transferred from primary consumers to secondary consumers?

15%

Approximately what percentage of energy is transferred to tertiary consumers?

10%