13 2 Biotic and Abiotic Factors KEY CONCEPT

13. 2 Biotic and Abiotic Factors KEY CONCEPT Every ecosystem includes both living and nonliving factors.

13. 2 Biotic and Abiotic Factors An ecosystem includes both biotic and abiotic factors. • Biotic factors are living things. – plants – animals – fungi – bacteria plants

13. 2 Biotic and Abiotic Factors • – – – Abiotic factors are nonliving things. moisture temperature wind sunlight soil sunlight moisture

13. 2 Biotic and Abiotic Factors Changing one factor in an ecosystem can affect many other 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. Hotspots

13. 2 Biotic and Abiotic Factors • A keystone species is a species that has an unusually large effect on its ecosystem. • Keystone is the stone at the center of an arch that holds the arch together. Without it – the walls collapse (necessary) keystone

13. 2 Biotic and Abiotic Factors • Keystone species form and maintain a complex web of life. Ex. beaver • Build dam- creates a wetland creation of wetland ecosystem increased waterfowl Population increased fish population keystone species nesting sites for birds

13. 2 Biotic and Abiotic Factors Sea otter