The section deals with human interaction with the desert biome. I have included a ‘structure sheet’ which will help you to plan your Geoecology answers. Many students try to learn off sample answers. This can take a long time and forgetting one sentence can lead to a person forgetting all of the sentences that follow it. It is always better to focus on understanding key words. Try using the structure sheet to write your own answer to the question.
HIGHER LEVEL
EXAM QUESTION Biomes are altered by human activity. Discuss.
2014 Q18 80M
Remember, you can also discuss the positive impacts of human interaction with biomes. This structure sheet deals with three aspects, but you can also include soil conservation methods as a fourth aspect. Your knowledge of human interaction with the Sahel region in the final section of Chapter 9 Mass Movement and in Chapter 27 Soils will help here. It is not merely enough to describe how humans interact, but also the effects of their interaction.
Marking Scheme 3 aspects 27 + 27 + 26 Aspect named 3 @ 4m each Each aspect 8 SRPs @ 2m each Overall cohesion 7m/7m/6m
The aspects discussed for this structure sheet follow a logical order: 1. Deforestation to make way for agricultural land 2. Overgrazing as the population of the Sahel and its herd size increased 3. Farmers securing loans and growing crops which led to further soil degradation While it is not necessary to write in this specific order, it does make sense to do so as one leads on to the other.
Structure Sheet
Aspect 1: Deforestation Cutting down and clearing forestry
Firewood for cooking and heat 3% population growth per annum
Khartoum in Sudan – 100 km radius
Mali – 500 000 acres – 30 times faster than replaced Prevents soil erosion
Deciduous leaves – plant litter Dust storms and loss of fertility
Competition for land – depletion of nutrients Loss of soil fertility – grass scarce
Sedentary farming – continually grazed Soil structure damaged – compaction from hooves Boreholes and wells sunk – water depletion
Salinisation and calcification – increased dust storms
Note that these are not SRPs, but act as SRP ‘cues’. This method should improve your understanding of the topic. When you have chosen your key points, practise writing your answer with the aid of your notes and this book. You will gradually become more comfortable with the topic and eventually find that you need only these cues to write the answer.
Aspect 3: Overcropping Increased population – demand for food
Land used for crops trebled in 50 years
Land not left fallow Soils become infertile Fertilisers not used – dung for fuel
