Energy transfer in ecosystems Re-cap

1. Energy transfer in ecosystems Re-cap • What is this • diagram? • What does it • show? • Write down 2 • food chains • from this • diagram Energy in Ecosystems

2. Today we are learning about: • How energy is transferred in ecosystems. • Where energy is lost in a food chain. • What energy is available to the next level in a • food chain. • Success criteria • Explain where energy goes in food chains • How much is lost and how much is passed on • between levels. Energy in Ecosystems

3. This is a typical food chain. Grass grasshopper frog snake • What do the arrows represent? • How much energy do you think is passed • on from one organism to the next? • What do you think happens to the energy • not passed on? Where do you think the original energy came from for this food chain? Energy in Ecosystems

4. Energy not available to the next organism is about 90% Movement Heat production Energy is lost in these ways Undigested waste Energy in Ecosystems

5. How much energy is available to the next level? Yes only 10% which can be used for growth. In a typical food chain the energy available to the next level in the chain quickly decreases for example. If the units of energy started at 100,000 for the grass by the snake it would be 100. 100,000 10,000 1000 100 Energy in Ecosystems

6. This dramatic loss of energy limits the length of food chains as there needs to be enough energy to support the next organism in the food chain. What have we learned? Are food chains efficient at passing energy on? • What happens to most of the energy in the food chain? • How much is available to be passed on to the next level in the chain? • How much is lost? Energy in Ecosystems