Across
- 4. the place where a plant or animal lives
- 5. decayed plant or animal matter
- 6. to die out
- 9. seasonal wind that brings either dry or moist air
- 11. semi-dry grasslands or prairies
- 12. cannot ever be replaced
- 17. a group of plants and animals that depend on each other and the environment for survival
- 18. a large stream of surface seawater
- 19. nonrenewable resources that formed from the remains of ancient plants and animals
Down
- 1. electricity from water power
- 2. the spread of desertlike conditions
- 3. any material in nature that people use and value
- 7. replaced by the Earth naturally
- 8. area of tall grasses and scattered trees and shrubs
- 10. the clearing of trees
- 13. a region's average weather conditions over a long period
- 14. the short-term changes in the air for a given place and time
- 15. permanently frozen layers of soil
- 16. place where two air masses of different temperatures or moisture content meet