Teaching Sustainability With Rocks, Soils, Flora And Fauna

The world is facing urgent global challenges – such as global warming and threats to water and food security – that must be addressed to avoid a disastrous future for humanity. Markwick (2023, p. 7) argues: ‘For humankind to acknowledge and appreciate that we are an integral part of the Earth’s biosphere requires a secure knowledge of the complex and fragile interactions between fauna and flora within ecosystems.

The journey towards such ‘environmental consciousness’ arguably begins in and progresses throughout a pupil’s school life. It should therefore become part of a pupil’s statutory learning. Towards this aim we need to consider carefully how we equip our young to meet the complex sustainability challenges they will face without creating an ethos of anxiety (Panu, 2021; Bright and Eames, 2022) but rather a future full of hope. 

Pupils following the national curriculum will be familiar with the idea of food chains and the interdependencies between animals and plants, but it is unlikely that they will have encountered the importance of rocks and soils in this ecological equation. I aim to present an engaging approach that shows how the often-disconnected topics of rocks, soils, flora and fauna can be interrelated, creating a purposeful learning experience that uses these important ideas to develop a greater appreciation for nature, agriculture and (ultimately) sustainability.

The purpose of the activities is to support pupils’ deeper understanding of the complexities within an ecosystem. In this case, pupils learn how rocks are an essential ingredient in the creation of soils and so can determine both the physical and chemical properties of the soils. This, in turn, constrains the types of plants that can grow in the soils.

For example, some plants will only thrive in alkaline soils, others only in acidic soils. The plants that naturally grow in any ecosystem will support the types of animals that exist in the ecosystem. By making these connections between rocks, soils, flora and fauna, pupils will develop their critical thinking skills and begin to see how the rocks underneath their feet can influence the appearance of their environment.

Activities

1. Introducing rocks

Pupils are often introduced to rock types in a traditional manner – igneous, metamorphic and sedimentary rocks are described and the characteristics are then linked to modes of formation.

This is fine, but for this activity, it is important to provide students with actual samples. Pictures can supplement this activity but should not be pupils’ only experience of the rocks; they can also explore the texture of each rock using touch and a magnifying glass. It can be interesting to see if any of the rocks react with vinegar (an acid) as well. It is important to provide a range of examples for each rock type.

2. Investigating soil types

Four soil types are provided: chalky, peaty, sandy and loamy soils.*¹ Pupils can be shown a simple diagram of soil composition (Figure 1). It is important to stress the mineral (from rocks) and organic (from dead organisms, which can be linked to decomposers etc.) components of each soil.

A) Pupils are asked to visually explore the composition of each soil and sketch what they see (Table 1). It is important at this stage for pupils to carefully observe what they see in each soil. For example, they should see grains of quartz in the sandy soil and fragments of twigs and leaves in the peaty soil. The question to ask then is: ‘What rock do you think each soil was made from?’ Pupils should be able to make the links between sandstones and sandy soils and limestone and chalky soils very easily. Peat (if you can obtain a sample) is also an easy link to make.

B) An important physical property of a soil is its permeability (how easily water can move through the soil). The greater the porosity, the more permeable the soil will be. If a soil is too permeable, it will not retain enough water for plants, whereas if it is impermeable, it will become waterlogged, which is also not good for plant growth. For this activity, pupils will measure the amount of water that permeates through each soil sample in a given time (Table 2).

C) How acidic or alkaline is the soil? To measure the acidity of the filtrates collected in the above stage, pupils can use the juice from red cabbage*². Table 3 provides the method for this experiment.

D) A soil’s acidity is a critical chemical property that can determine the types of plants that grow in it. To elaborate upon this, pupils can be shown typical landscapes such as chalk (limestone), granite, peaty and sandy. Pupils can discuss the types of plants that grow in these landscapes and potentially research them in greater depth. Once pupils have a sound grasp of the connection between rock type, soil composition and the types of flora they support, they can investigate the typical fauna that thrive in these different landscapes. A question that could be asked is: ‘What other factors are important in creating ecosystems such as these?’ The answer is often and correctly stated as climate.

This series of experiments takes pupils on a journey that helps them to see how rocks, soils, flora and fauna are closely linked in the creation of any ecosystem or environment. These ideas can then be extended to agriculture and the need for farmers to be acutely aware of the soils they are working with. Again, this relates very much to the underlying rocks and the flora and fauna already present in the ecosystem.

Table 4 is a self-contained activity that asks pupils to link crops to soil types. Some research will be necessary to make these connections. Once pupils have identified the soil type, test them to see if they can predict the rocks that exist in those regions.

Soil type	Plants
Chalky	Sweetcorn, cabbage, broccoli
Peaty	Celery, potatoes, peppers, beans
Clay	Wheat, sweetcorn, rice
Sandy	Carrots, radish, watermelon, apples

Through such active learning, pupils will appreciate the complex connections that exist in any ecosystem and begin to understand how fragile they can be. For example, if a farmer needs to grow a particular crop, they must have a sound understanding of the soil composition on their land – and, if it is not appropriate, understand how it can be adapted, or change the type of crop grown. In a time when we face mounting concerns about food security, such knowledge is invaluable.

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References

Bright, M.  L. and Eames, C.  (2022).  From apathy through anxiety to action:  Emotions as motivators for youth climate strike leaders. Australian Journal of Environmental Education, 38(1), 13-25.

Markwick, A. (2023) Educating for Sustainability. Journal of Emergent Science, (24), 5-13. ASE.

Panu, P. (2020) ‘Anxiety and the Ecological Crisis: An Analysis of Eco‐Anxiety and Climate Anxiety’, Sustainability, (12), 7836.

Dr Andy Markwick is the Primary Science and Learning and Teaching (MA) lead for Primary PGCE and a senior lecturer in Secondary Science at the IOE (UCL). He can be reached at andy.markwick@ucl.ac.uk.