In this lesson students examine factors that affect population sizes such as destruction of habitats. They consider how energy flows into and out of an ecosystem via the pathways of food webs, and how it must be replaced to maintain the sustainability of the system and investigate how ecosystems change as a result of events such as bushfires, drought and flooding.
Read students the poem My Country by Dorothy Mackellar. Ask them what natural disasters are mentioned in the poem and how does the poem describe the impact on the Australian ecosystems of these natural disasters.
- Revisit how food webs work together (from lesson 1) and depend on a producer. Discuss the implications of a producer being absent.
- Brainstorm the types of disasters that could remove the producers from an ecosystem.
- Jigsaw activity. This involves students becoming specialists for their particular natural disaster, and then sharing their knowledge with a smaller group to find similarities and difference. Break students into groups to study three natural events that impact the ecosystem.
- One representative from each group (bushfires, floods, droughts) should meet with each other and describe the impact of their event on an ecosystem.
- Suggest that students can create a positive impact on their school environment. Conduct the activity Who can live here?
Create an action plan for your school grounds that maximises ecological biodiversity.