| A | B |
|---|
| primary succession | development of plant & animal life in an area w/o top soil |
| ecosystem | all the living and nonliving things in an environment including their interactions with each other |
| natural events that change ecosystems | floods, storms, volcanos, tornados, earth quakes, etc |
| examples of how organisms change ecosystems | beavers making dams, coral building reefs, elephants stumping on plants, red tide killing sea life, etc |
| secondary succession | development of new plant & animal life where a community already exists |
| time for secondary succession | doesn't take as long as primary |
| what people infect the environment with | pollution |
| pollution | a harmful change to the environment |
| climax community | final stage of succession that usually ends up with a natural forest |
| pioneer species | first living species in a lifeless area |
| threatened species | is at risk of becoming endangered |
| endangered species | at risk of becoming extinct |
| extinct species | no longer exist on earth |
