Across
- 2. damage to a habitat by air, water, and land pollution
- 3. rain,snow, sleet, or fog with a pH below 7; causes the deterioration of forests, lakes, statues, and buildings
- 4. field of biology that studies methods and implements plans to protect biodiversity
- 5. nonnative species in an area; may take over niches of native species in an area and eventually replace them
- 8. programs that release organisms into an area where their species once lived in hopes of reestablishing naturally producing populations
- 12. variety of life in an area
- 13. layer of the atmosphere that helps to protect living organisms on Earth's surface from damaging doses of ultraviolet radiation from the sun
Down
- 1. separation of wilderness areas from each other; may cause problems for organisms who need large areas for food or mating
- 2. natural strips of land that allow the migration of organisms from one wilderness area to another
- 5. different environmental conditions that occur along the boundaries of an ecosystem
- 6. when the last members of a species dies
- 7. philosophy that promotes letting people use resources in wilderness areas in ways that will not damage the ecosystem
- 9. a species in which the number of individuals falls so low that extinction is possible
- 10. species that has rapidly decreasing numbers of individuals
- 11. when members of a species are held by people in zoos or conservation facilities