| A | B |
|---|
| Water cycle | the continuous movement of water between earth's surface and the air |
| succession | the process of an ecosystem changing into a different ecosystem |
| carbon cycle | the continuous movement of carbon among living things |
| extinct species | all the members of that species have died |
| biome | a major land ecosystem of earth |
| estuary | an ecosystem that is part salt and part fresh water |
| pioneer species | the first species to come back into a barren area |
| nitrogen cycle | involves trapping a gas into compounds in the soil |
| taiga | a cool forest biome containing evergreen trees |
| nekton | the category of organisms in a water ecosystem that includes large, active swimmers |
| evaporation | changing of a liquid into a gas |
| primary succession | the formation of a new community where few living things exist |
| climax community | the final stage in succession |
| savanna | the African grasslands. |
| endangered species | is in danger of becoming extinct |
| threatened species | has a low number of creatures, but not low enough to be considered endangered |
| tundra | this biome has no trees and is frozen underground all year long |
| compost | a mixture of dead organic material used as fertilizer |
