Across
- 2. the illegal killing of wildlife
- 5. habitat where fresh water and saltwater meet
- 8. type of resource that is naturally replaced in a relatively short time
- 9. the process of reclaiming and reusing raw materials
- 11. soil that is frozen all year
- 14. the pattern of overlapping food chains in an ecosystem
- 20. containing unstable atoms
- 22. practice of raising fish and other water organisms for food
- 24. the advance of desert-like conditions into an area that was previously fertile
- 26. species that have naturally evolved in an area
- 27. a change to an environment with a negative effect on living things
Down
- 1. the organism that benefits by living on or in a host in parasitism
- 3. the process by which water, wind, or ice moves particles of rock or soil
- 4. factory where crude oil is separated into fuels and other products
- 6. any factor that can change in an experiment
- 7. place where an organism lives and provides the things it needs
- 10. an interaction in which one organism kills and eats another
- 12. a group of ecosystems with similar climates and organisms
- 13. the number of different species in an area
- 15. an organism’s particular role in an ecosystem
- 16. an organism that can make its own food
- 17. the series of predictable changes that occur to a community over time
- 18. water stored in underground layers of rock and soil
- 19. a relationship between two species in which both benefit
- 21. a species that influences the survival of many others in an ecosystem
- 23. layer of dead leaves and grass on top of the soil
- 25. the typical weather pattern in an area over a long period of time