Teaching sequence

Lesson objective

In this lesson students:

• test various abiotic components that impact an ecosystem
• formulate questions or hypotheses that can be investigated scientifically
• plan, select and use appropriate methods, including field work and laboratory experimentation, to collect reliable data, assess risk and address ethical issues associated with these methods
• select and use appropriate equipment, including digital technologies, to systematically and accurately collect and record data
• analyse patterns and trends in data, including describing relationships between variables and identifying inconsistencies
• use knowledge of scientific concepts to draw conclusions that are consistent with evidence
• evaluate conclusions, including identifying sources of uncertainty and possible alternative explorations, and describe specific ways to improve the quality of the data
• critically analyse the validity of information in secondary sources and evaluate the approaches used to solve problems
• evaluate the balance that is needed between human and ecosystem needs.

Introduction

Discuss the impact of changing an environment by building a house, planting a flowerbed and planting food. Is one type of change better than the others? Are humans more important than other biotic components in the ecosystem?

Why or why not? 

Core

1. Introduce the ideas of ‘biotic’ and ‘abiotic’ components of an ecosystem. Use the learning object Analysing an ecosystem to highlight the many different types of abiotic and biotic components of an ecosystem.
2. Ask students to locate their position on the map of Australia on the Australian Resources Information System website. On the left side of the screen click on the folder for level 4, then the box for pH. This will show the known pH for your area. The legend will help students determine the pH of the soil.
3. Ask students what pH is. Why is it important to plants? Ask students whether the topsoil in the garden is a true indication of the pH of soil in the area. Why or why not?
4. Complete the experiment Testing soil pH (Word, 401 KB) to determine the pH of local soil. Was the soil the same or different to that shown on the Australian Resources Information System website?
5. Ask students what the difference is between topsoil and subsoil.
6. Complete the worksheet Analysing soil (Word, 383 KB) to determine the type of soil at the location chosen. Ask students what locations might have sandy or clay soil and how might the type of soil impact the types of plants growing in the area.
7. Choose three areas in the school garden that can be used for testing. Repeat the testing of pH of the soils in those areas. Ask students how they might change the pH of the soil and what impact it might have on the plants that are growing there. (Answer: Modifications include adding wastewater with detergents, building rubble or a variety of fertilisers.) Ask students what factors they will try to control between the three areas.
8. Leave the area for two weeks and then retest the soil.
9. Mark several 1 square metre quadrats in a naturalised area. Discuss the ethics of how you might examine the biotic components of the ecosystem. Ask students to identify the different plants and animals in their quadrat. A local field guide can aid the identification of the plants and animals.

Conclusion

Ask students to determine the local building regulations in their area. Are they adequate? What factors, economic or otherwise, impact on these regulations?