| A | B |
|---|
| Biome | a group of land ecosystems with similar climates and organisms |
| Canopy | The tall trees form a leafy roof. |
| Understory | A second layer of shorter trees and vines |
| Desert | An area that receives less than 25 centimeters of rain per year. |
| Grassland | An area populated by grasses and other non-woody plants. |
| Savanna | Scattered shrubs and small trees. It receives as much as 120 centimeters of rain per year. |
| Deciduous Tree | Trees that shed their leaves and grow new ones each year. |
| Coniferous Tree | Trees that produce their seeds in cones and have leaves shaped like needles. |
| Tundra | An extremely cold and dry biome |
| Permafrost | Frozen soil all year. |
| Estuary | Where fresh water from a river meets salt water from the ocean |
| Intertidal Zone | Between the highest high-tide line and the lowest low-tide line. |
| Nertic Zone | Below the low-tide line is a region of shallow water |
| Succession | The series of predictable changes that occur in a community over time. |
| Primary Succession | The series of changes that occur in an area where no soil or organisms exist. |
| Secondary Succession | The series of changes that occur in an area where the ecosystem has been disturbed, but where soil and organisms still exist. |
| Pioneer Species | The first species to populate an area. |
