| A | B |
|---|
| Biome | one of earths large ecosystems |
| Carbon cycle | the continuous exchange of carbon dioxide and oxygen among living things |
| Estuary | the boundary where a fresh water ecosystem meets a saltwater ecosystem |
| nekton | organisms that swim through the water in aquatic ecostystems |
| nitrogen cycle | the continual trapping of nitrogen gas in compounds |
| primary succession | the beginning of a community where few if any living things exist |
| succession | the process of one ecosystem changing into a new and different ecostystem |
| taiga | a cool forest biome of conifers in the upper North Hemisphere |
| water cycle | the continuous movement of water between Earth's surface and the air, changing from liquid to gas |
| evaporation | the change of a liquid into a gas below the boiling point |
| pioneer species | the first community living in a lifeless area |
| extinct species | when the last of a species kind dies out |
