| A | B |
|---|
| renewable resource | naturally replaced in a relatively short time |
| nonrenewable resource | not replaced as they are used |
| pollution | any change to the environment that has a negative effect on living things |
| clear-cutting | cutting down all trees in an area at once |
| selective cutting | cutting some trees and leaving some of various sizes and species |
| sustainable yield | amount that can be harvested without reducing the future supply |
| fishery | an area with a large population of ocean oganisms |
| aquaculture | raising fish and other ocean dwelling organisms for food |
| biodiversity | number of different speices in an area |
| keystone species | species that influences the survival of many other species in an ecosystem |
| extinction | disappearance of all members of a speices |
| endangered species | species in danger of becoming extinct |
| threatened species | species that could become endangered |
| habitat destruction | loss of natural habitat |
| habitat fragmentation | breaking larger habitats into smaller habitats |
| poaching | illegal killing or removal of wildlife species |
| captive breeding | mating of animals in zoos or wildlife preserves |
