Energy in Ecosystems

Nitrogen in ecosystems

Energy in Ecosystems

Energy in ecosystems

Re-cap

How much energy is lost between each organism?

What is the role of decomposers in ecosystems?

What type of organisms are decomposers?

How much energy is past on at each level?

Energy in Ecosystems

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

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

Nitrates in the soil are produced by decomposers (bacteria and fungi). They break down nitrogenous waste (faeces and urine) and the remains of dead animals and plants to produce ammonia compounds.

Most plants get there nitrogen from nitrates in the soil which they take up through their roots

Nitrifying bacteria then convert the ammoniumcompounds into nitrates

Energy in Ecosystems

Plants take in nitrates through their roots and make their own 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

Free living 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 bydenitrifying soil bacteria which is released back into the atmosphere.

Energy in Ecosystems The nitrogen cycle

Energy in Ecosystems

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

What have you learned?

What do nitrifying bacteria do in the cycle?

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 denitrifying bacteria do in the cycle?