more biology

4. Release of harmful materials into the environment
6. A stable, mature community that undergoes little or no change in species over time
8. First species to populate an area during primary succession
11. A habitat in which the fresh water of a river meets the salt water of the ocean.
15. A group of ecosystems that share similar climates and typical organisms
17. the variety of life in the world or in a particular habitat or ecosystem.
19. Ecological rule that states that no two species can occupy the same exact niche in the same habitat at the same time
20. relating to water
21. symbiotic association between a fungus and a photosynthetic organism
22. An increase in the average temperature of the earth's atmosphere (especially a sustained increase that causes climatic changes)

1. spots on the ocean floor where hot gases and minerals escape from earth's interior into the water
2. A community of organisms where there are several interrelated food chains
3. Succession following a disturbance that destroys a community without destroying the soil
5. destruction of forests
7. Portion of the marine biome that is shallow enough for sunlight to penetrate.
9. plants and animals that have migrated to places where they are not native
10. A geographic region categorized by a particular combination of average annual temperature, annual precipitation, and distinctive plant growth forms on land
12. an area that gets no sunlight.
13. A species that influences the survival of many other species in an ecosystem
14. species that are native to and found only within a limited area
16. The number of people in an area exceeds the capacity of the environment to support life at a decent standard of living.
18. An ecological succession that begins in an area where no biotic community previously existed