Across
- 1. Less than 250 mature adults
- 3. Developed first wildlife refuge plan
- 6. down to soil and humans can influence
- 9. Became extinct due to market hunting
- 12. Adds to reduction
- 14. Biological process that naturally occurs to remove contaminants
- 15. indicator species of healthy habitats
- 16. Adds to abundance
- 17. Passed in 1900 and prohibited market hunting
- 19. Adaptation for trees to receive oxygen from anerobic soil
- 21. Ensures safe standards for waste discharge & point-source pollution
Down
- 2. Mostly privately owned land with lots of grazing areas
- 4. Number of organisms surviving long enough to be added to population & reproduce
- 5. Act of rebuilding an area suffering severe habitat loss
- 7. 40% of oxygen is produced here
- 8. Spongy substance formed by partially decomposed vegetation
- 9. used to categorize terrestrial biomes
- 10. Rest stop for migratory birds to replenish resources
- 11. down to rock where lichen and moss are pioneer species
- 13. Organizes organisms by similarities and differences
- 18. These contain about 84% of United States' freshwater
- 20. How organisms match and respond to environmental conditions