Chapter 3

6. a species that no longer exists in a specific area
7. on a large scale, most natural ecosystems are in this state
8. The process of establishing and replacing a community following a disturbance
10. A volcanic eruption is an example of this
12. harmful contaminants released into the environment
14. may become threatened or endangered because of a combination of factors
15. The variety of life found in an area
16. Certain minerals particularly one is able to do this.

1. a species facing imminent extirpation or extinction
2. A species no longer found on earth
3. Taking responsibility for managing and protecting the environment
4. Introduced species with growing populations that spread and have a negative effect on their environment
5. The number of species in an area
9. Acids move through the water cycle, sometimes over long distances, before returning to earth in this form
11. A forest fire is an example of this
13. species are likely to become endangered if current trends and conditions continue