1. An ecosystem in which the biotic and abiotic features remain constant is in . 2. The series of changes over time after a natural disaster is called .

3. is the removal of most of the trees in a forest ecosystem.

4. The process of removing mature trees but leaving younger ones is .

5. involves taking responsibility for protecting the environment.

6. Acid precipitation is caused by the chemicals nitrogen oxides and .

7. Non-native organisms that have a negative impact on ecosystems are .

8. such as the Hilliardton Marsh are important aquatic ecosystems.

9. The process of breaking up large ecosystems into smaller parts is .

10. species like the barn owl are at risk of becoming extinct.