| A | B |
|---|
| biodiversity | variety of life in an area; usually measured as the number of species that live in a an area |
| extinction | when the last members of a species die |
| threatened species | species that have rapidly decreasing numbers of individuals |
| endangered species | species in which the number of individuals falls so low that exstinction is possible |
| habitat fragmentation | separation of the wilderness areas from each other; may cause problems for organisms that need large areas for food or mating |
| edge effect | different enviromental conditions that occur along the boundaries of an ecosystem |
| acid precipitation | rain, snow, sleet or fog with a ph below 7; causes the deterioration of forests, lakes, statues, and buildings |
| ozone layer | layer of the atomosphere that helps protect living organisms on earth's surface from damaging doses of ultraviolet radiation from the sun |
| exotic species | non-native species in an area; may take over niches of native species in an area and eventually replace them |
| conservation biology | the field that studies methods and implements plans to protect biodiversity |
| sustainable use | philosophy that promotes letting people use resourses in wilderness areas in way that will not damage the ecosystem |
| habitat corridors | natural strips of land that allow the migrations of organisms from one wilderness area to another |
| reintroduction programs | organizations that release organisms into an area where their species once lived in hopes of reestablishing naturally reproducing populations |
| captivity | when members of a species are held by people in zoos or other conservations facilities |
| chlorofluorocarbons | synthetic chemicals that break down the ozone layer |
| habitat degradation | damage to a habitat by air, water, and land pollution |
