Topic 8.2: Energy Flow Through Ecosystems

Ecosystem

A biological community of interacting organisms and their physical environment.

Law of Conservation of Mass

Matter is not created nor destroyed in any chemical or physical change

Primary Producers

the first producers of energy-rich compounds that are later used by other organisms

Primary Consumers

animals that feed on producers; ex. herbivores

Secondary Consumers

eat primary consumers

Tertiary Consumers

eat secondary consumers

Detritivores

feed on plant and animal remains and other dead matter

Decomposers

Organisms that break down the dead remains of other organisms

Detritus

Dead organic matter

Primary Production

Amount of light energy converted to chemical energy by autotrophs.

Gross Primary Production

The total primary production of an ecosystem.

Net Primary Production

the gross primary production of an ecosystem minus the energy used by the producers for respiration.

Net Ecosystem Production

The gross primary production of an ecosystem minus the energy used by all autotrophs and heterotrophs for respiration.

Limiting Nutrient

single essential nutrient that limits productivity in an ecosystem

Eutrophication

A process by which nutrients, particularly phosphorus and nitrogen, become highly concentrated in a body of water, leading to increased growth of organisms such as algae or cyanobacteria.

Secondary Production

Amount of chemical energy in consumers' food that is converted to new biomass.

Production Efficiency

The fraction of energy stored in food that was not used for cell respiration.

Trophic Efficiency

Percentage of production transferred from one trophic level to the next.

Trophic Level

Each step in a food chain or food web

Energy Pyramid

A diagram that shows the amount of energy that moves from one feeding level to another in a food web

Biogeochemical Cycles

process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another

Bioremediation

The use of living organisms to detoxify and restore polluted and degraded ecosystems

Biological Augmentation

Uses organisms to add essential materials to degraded ecosystems.