1. 13.2 Biotic and Abiotic Factors Objective: Students will know that an ecosystem includes both biotic and abiotic factors AND that changing one factor in an ecosystem can affect many other factors.

2. 13.2 Biotic and Abiotic Factors KEY CONCEPT Every ecosystem includes both living (biotic) and nonliving (abiotic) factors.

3. 13.2 Biotic and Abiotic Factors Biotic factors are living things. –plants –animals –fungi –bacteria plants

4. 13.2 Biotic and Abiotic Factors Abiotic factors are nonliving things. –moisture –temperature –wind –sunlight –soil moisture sunlight

5. 13.2 Biotic and Abiotic Factors List the biotic and abiotic factors in this picture Share with your neighbors Every ecosystem contains biotic and abiotic factors

6. 13.2 Biotic and Abiotic Factors Biodiversity is the assortment, or variety, of living things in an ecosystem. –Rain forests have more biodiversity than other locations in the world, but are threatened by human activities. (50% of the world’s plant and animals species are here)

7. 13.2 Biotic and Abiotic Factors Biodiversity has to do with: Number of species NOT Population number

8. 13.2 Biotic and Abiotic Factors Extinctions lower biodiversity!!!

9. 13.2 Biotic and Abiotic Factors A keystone species is a species that has an unusually large effect on its ecosystem. Ex: A beaver keystone Their removal from the ecosystem may cause a ripple effect felt across an entire ecosystem

10. 13.2 Biotic and Abiotic Factors By felling trees to construct dams, Beavers: –Change free flowing streams into ponds, wetlands, and meadows –Lead to an overall increase in biodiversity creation of wetland ecosystem increased waterfowl Population increased fish population nesting sites for birds keystone species

11. 13.2 Biotic and Abiotic Factors More variety of fish- Fish attract birds Insects inhabit pond and dead trees along the shore- Insects attract birds Animals that prey on birds are attracted to the pond creation of wetland ecosystem increased waterfowl Population increased fish population nesting sites for birds keystone species

12. 13.2 Biotic and Abiotic Factors Other keystone species