KEY CONCEPT Every ecosystem includes both living (biotic) and nonliving (abiotic) factors.

Biotic factors are living things. plants animals fungi bacteria plants

Abiotic factors are nonliving things. moisture temperature wind sunlight soil moisture sunlight

Every ecosystem contains biotic and abiotic factors List the biotic and abiotic factors in this picture

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)

Number of species NOT Population number Biodiversity has to do with: Number of species NOT Population number

Extinctions lower biodiversity!!!

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

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

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