Teaching Sequence

Work through this resource material in the following sequence:

20 minutes	Part B: Impact from the Fires
15 minutes	Part C: Impact from the Fires - Introduced Species
15 minutes	Part D: Impacts from the Fires - Species Loss
30 minutes	Reflection

Part A: Activating Prior Knowledge

Step 1.

Begin the lesson by distributing a copy of the Student Worksheet to each student and inviting them to complete a THINK PAIR SHARE routine around the following questions (available on the Student Worksheet):

What is a food chain?
What is a food web?
What do the arrows in a food chain or food web mean?

Think Pair Share
THINK PAIR SHARE is a collaborative learning strategy in which students work together to solve a problem or answer a question.
THINK - Students independently think about an issue or question or question and record their thoughts.
PAIR - Students work in pairs to discuss their ideas and record new thoughts.
SHARE - Students share their thoughts with the whole group or with other pairs to reach consensus.

Step 2.

Once complete, invite students to share their answers with the class. Use the following definitions to clarify student answers:

What is a food chain?
Suggested answer: A food chain is a diagram that shows the feeding relationships between plants and animals.
What is a food web?
Suggested answer: A food web is a way of graphically showing all the interconnecting food chains within an ecological community. Because relationships in nature are complex and involve all sorts of interconnections and energy flows, these relationships are best shown as a food web. A food chain will only show how the energy flows between one producer and several consumers.
What do the arrows in a food chain or food web mean?
Suggested answer: The arrows show the flow of energy between organisms in a food chain. Plants are at the beginning of the food chain and they get their energy from sunlight. Animals will get their energy from either eating plants or other animals: herbivores get their energy from eating the plants; carnivores get their energy from eating other animals; omnivores get their energy from both plants and animals, and detritivores get their energy from dead plants and animals.

Part B: Impact from the Fires

Step 1.

Explain to students that in this lesson they will be looking at how bushfires affect ecosystems by using a model of a food web. Share the following clips with students and invite them to record anything that they find interesting or important:

Jess Marsh, Kangaroo Island Invertebrate Scientist—Roles of Invertebrates in Ecosystems (https://vimeo.com/537486177)

Once complete, invite them to share their thoughts with the class.

Step 2.

Give each student a copy of theFood web factsheet.

Explain that many of the species on this food web come from the Flora, Fauna, Fire resource.

Invite students to work in pairs to think about how the energy might flow through this food web. They can do this by adding arrows onto the image (they might find some information about what these organisms consume on this page). Students should use a grey-lead pencil to add in their arrows.

Step 3.

Once complete, work as a class to check through the placement of the arrows, using the image below to clarify student work:

How did they go?
Were they mostly correct?
What was confusing for them?

Year 9 differentiation: You could use this as an opportunity to explore how an understanding of trophic structures can help to make sense of the direction of the arrows. Share the Trophic Levels Factsheet and spend a few minutes discussing what this tells us about the flow of energy within an ecosystem. Does this image help to understand how the energy flows in the ecosystem you’ve just looked at?

Where necessary, students can then make amendments to their food webs by rubbing out any arrows going in the wrong direction. It will be useful to have the arrows heading in the correct directions for the next activity.

Step 4.

Now explain to students that they are to imagine that a bushfire has burned through their ecosystem. All the animals managed to get away, but the grasses have been burned.

Students should work in their groups to identify which organisms will be impacted by the loss of grass species. They should use a red pen to circle those species that are affected. Remind students to follow the impacts up through the web.

Invite students to share their results with the class, and use the image below to clarify their answers.

Step 5.

Engage students in a brief discussion around their food web. Consider the following questions in your discussion:

How many species did they identify would be impacted by the loss of grass?
What might be the immediate effects?
What might be the long-term effects?

Differentiation: Students needing extension can also consider the following:

How might the loss of grass in this ecosystem affect the flow of energy into and out of this ecosystem?

Explain to students that a bushfire that only affects grasses would probably be a pretty low-intensity fire and that many bushfires cause damage to many different flora and fauna species.

Part C: Impacts from the Fires - Introduced Species

Step 1.

Now explain to students that another impact of bushfires is that because the native species (both flora and fauna) are recovering from the fire, invasive species can often begin to colonise the area; this is because many invasive species recover more quickly than native species after a bushfire. In addition, because the native species take time to recover, the invasive species have the chance to spread rapidly and suppress native species recovery.

Explain to students they will now think about how an invasive species might affect their food web.

Give groups one of the Invasive Animal Images, printed and cut out. Explain that both of these animals are carnivores.

Working in their groups, invite students to add their invasive species to their food web. They should then use a blue pen to show how the energy flow in their food web might be affected by this invasive species.

Step 2.

Once complete, invite students to share their food webs with the class, and to explain why they placed their blue arrows in the way they did.

Step 3.

Through a class discussion, invite students to reflect on how the food web might be affected by multiple invasive species. Consider the following questions in your discussion:

Based on your food web, what types of impacts would from invasive species would you expect to see in an ecosystem?
What might be the immediate effects?
What might be the long-term effects?

For example:

Year 9 differentiation: Students needing extension can also consider the following:

How might the arrival of invasive species into this ecosystem affect the flow of energy into and out of this ecosystem?
What about if grasses were removed and invasive species arrived?

Part D: Impacts from the Fires - Species Loss

Step 1.

Display or direct students to this page (https://bit.ly/3mYDoQI) and navigate to the page about the Silver-headed antechinus. Invite students to read through the information about this species, and take a moment to reflect on the main statistics being presented, such as:

What was the pre-fire conservation status for this species?
What percentage of its habitat was burned in the recent fires?
What are some of the threats to this species post-fires?

Keep this page open as you will return to it shortly.

Step 2.

Now invite students to imagine that because of the bushfire, the Silver-headed antechinus is now missing from the food web. Students should work in their groups to use a green pen to cross out the Silver-headed antechinus and any species that it might have connections to.

For example:

Step 3.

Once complete, invite each group to team up with another group to discuss the following:

How might the loss of the Silver-headed antechinus affect the organisms below it on the food web?
How might the loss of the Silver-headed antechinus affect the organisms above it on the food web?

Year 9 differentiation: Students needing extension can also consider the following:

How might the arrival of predatory feral animals affect the trophic structure in this ecosystem?

You can then invite students to share their ideas with the class.

Step 4.

Now return to the page about the Silver-headed antechinus and invite students to work as a class to reflect on the following questions:

What information is provided about priority conservation actions for this species?
How do these relate to the information on your food web?

Reflection

Invite students to work independently to respond to the following (also available on the Student Worksheet):

Teacher Reflection

Take this opportunity to reflect on your own teaching:

What did you learn about your teaching practice today?
What worked well?
What didn't work so well?
What would you share?
Where to next?
How are you going to get there?

Beyond the Bushfires - Bushfires And Food Webs

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Summary

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