Nitrogen in ecosystems

1. Nitrogen in ecosystems Energy in Ecosystems

2. Energy in ecosystems Re-cap • How much energy is lost between each organism? • How much energy is past on at each level? • What is the role of decomposers in ecosystems? • What type of organisms are decomposers? Energy in Ecosystems

3. Today we are learning about: • The role of nitrogen in ecosystems • How nitrogen is cycled in ecosystems • Success criteria • Complete simple diagram of the nitrogen cycle • Describe how nitrogen passes through the cycle • Explain how different organisms make use of nitrogen • Explain the role of bacteria and fungi in the cycle Energy in Ecosystems

4. Animals and plants need to make proteins in their cells. For this they need nitrogen • Animals get their nitrogen by consuming plants or animals that have protein in their tissues. • This protein is digested and then converted into the • animals protein. Energy in Ecosystems

5. Most plants get their nitrogen from nitrates in the soil which they take up through their roots • Nitrates in the soil are produced by decomposers • (bacteria and fungi). • They break down nitrogenous waste (faeces and urine) • and dead animals and plants to produce ammonia. Nitrifying bacteria then convert the ammonium compounds into nitrates Energy in Ecosystems

6. Plants take in nitrates through their roots and make protein from them. Some plants have a relationship with soil bacteria which create nodules on their roots. These root-nodule bacteria can fix nitrogen from the soil which the plants can use. • Examples of plants that have this are peas, beans and clover (leguminous plants) Energy in Ecosystems

7. Free nitrogen fixing soil bacteria also fix nitrogen from the soil into nitrates that plants can take up in their roots. Some nitrates are converted to nitrogen by denitrifying soil bacteria which is released back into the atmosphere. Energy in Ecosystems

8. Energy in Ecosystems The nitrogen cycle

9. Activities • Collect an A1 piece of paper and large felt tip. • Use the labels and pictures to construct a • nitrogen cycle with your group. • You will need to add arrows to join it up. • (Check it with the peers and teacher) • Complete the diagram of the nitrogen cycle • and stick it in. • Complete the summary note by adding the • missing words and stick it in. Energy in Ecosystems

10. What have you learned? • Why is nitrogen so important to organisms? Where do animals get their nitrogen? Where do plants get their nitrogen? How are decomposers involved in the nitrogen cycle? What do nitrifying bacteria do in the cycle? What do denitrifying bacteria do in the cycle? Energy in Ecosystems