Energy in an Ecosystem

1. Energy in an Ecosystem

2. Energy in an Ecosystem • Autotrophs vs. Heterotrophs Produce own food Have to obtain food Primary producers consumers Plants Lion, rabbit, cow

3. Heterotrophs • Can be herbivores, carnivores, or omnivores • Also include scavengers and decomposers -Both are detrivores (eat detritus = dead organic matter) Break down dead organic matter

4. Models of energy flow • Food chain: • Food web: Simple model that shows how energy flows through an ecosystem Model representing the many interconnected food chains and pathways in which energy flows through a group of organisms

5. Food Chain • Each step in a food chain is called trophic level • Autotrophs or dead organic matter makes the first trophic level in all ecosystems • Arrows represent energy flow Producer Herbivore Omnivore Carnivore

6. Another food chain

7. Food Web • More complex than food chain because most organisms feed on more than one species

8. Another Food Web

11. Activity: Construct a Food Web Use the following information to construct a food web in a meadow ecosystem • Red foxes feed on raccoons, crayfishes, grasshoppers, red clover, meadow voles, and gray squirrels • Red clover is eaten by grasshoppers, muskrats, red foxes, and meadow voles • Meadow voles, gray squirrels, and raccoons all eat parts of the white oak tree

12. Crayfishes feed on green algae and detritus, and they are eaten by muskrats and red foxes • Raccoons feed on muskrats, meadow voles, gray squirrels, and white oak trees Identify all of the herbivores, carnivores, omnivores, and detritivores in the food web Describe how the muskrats would be affected if disease kills the white oak trees