| A | B |
|---|
| autotroph | Organisms that make their own food from the sun. |
| heterotroph | Organisms that get their energy by eating other living things. |
| scavenger | Animals that eat animals that have already died (they didn't kill). |
| decomposer | Organisms that break down and absorb nutrients from dead organisms. |
| food chain | A model to show how energy and nutrients move through an ecosystem. |
| trophic level | A feeding step in a food chain. |
| food web | A model that expresses all the possible feeding relationships in an ecosystem. |
| limiting factor | Factors that affect an organism's ability to live. |
| succession | Orderly, natural changes and species replacements that take place in communities. |
| primary succession | The colonization of new sites (example - on new lava flows). |
| climax community | A stable, mature community that undergoes little or no species change. |
| secondary succession | Sequence of community changes that takes place after a natural disaster. |
