1. The number of different species in an area.
Biodiversity
The number of different species in an area.

2. Biodiversity of Species on Earth

3. Reasons to preserve biodiversity Beauty Economic Value
Ecological Value
Species depend on each other for survival
Keystone Species influence the survival of many other species in the ecosystem
Factors Affecting Biodiversity
Size of Area
Climate
Niche Diversity

4. Extinction of a Species
Extinction - disappearance of all members of a species from Earth.
Endangered – species in danger of becoming extinct in the near future.
Threatened – species that could become endangered in the near future.

5. Causes of Extinction Habitat Destruction Poaching
The loss of a natural habitat
Deforestation – cutting down the trees
Desertification – creating a desert like community
Habitat Fragmentation – breaking up large habitats into smaller ones
Poaching
The illegal killing or removal of wildlife from an area

6. Causes of Extinction (Continued)
Introduction of Exotic Species
Species that are carried to an area by people
Examples:
Pollution