Across
- 2. Nonnative species in an area; may take over niches of native species in an area and eventually replace them
- 3. Seperation of wilderness areas from each other; may cause problems for organisms that need large areas for food or mating
- 4. Layer of the atmosphere that helps to protect living organisms on Earth's surface from damaging doses of ultraviolet radiation from the sun
- 6. Variety of life in an area; usually measured as the number of species that live in an area
- 7. Field of biology that studies methods and implements plans to protect biodiversity
- 9. Rain snow,sleet, or fog with a pH below 7; causes the deterioration of forests,lakes,statues,and buildings
- 10. Natural strips of land that allow the migration of organisms from one wildness area to another
- 11. When the last members of a species die
- 12. A species in which the number of individuals falls so low that extinction is possible
- 13. When members of a species are held by people in zoos or other conservation facilities
- 14. Philosophy that promotes letting people use resources in wildness areas in ways that will not damage the ecosystem
Down
- 1. Programs that release organisms into an area where their species once lived in hopes of reestablishing naturally reproducing populations
- 3. Damage to a habitat by air, water, and land pollution
- 5. Different environmental conditions that occur along the boundaries of an ecosystem
- 8. Species that have rapidly decreasing numbers of individuals