Causes of Large-Scale Deforestation Revision Notes | GCSE OCR Foundation Biology

What this lesson covers

Explore the main drivers of deforestation in tropical areas, focusing on agriculture for cattle ranching and rice cultivation, and the growing demand fo...

• Explain the main causes of large-scale deforestation in tropical areas
• Evaluate the impact of cattle farming on forest ecosystems
• Analyse the role of biofuel production in deforestation
• Compare the environmental costs and benefits of different land uses

Key ideas to keep in view

Use this lesson to stay inside B6.1 Monitoring and maintaining the environment while connecting the detail back to the wider B6: Global challenges topic.

• B6: Global challenges
• B6.1 Monitoring and maintaining the environment
• GCSE OCR Foundation Biology

Lesson notes preview

Read the core explanations from Causes of Large-Scale Deforestation before testing yourself from memory.

• Every minute, an area of tropical forest the size of 20 football pitches disappears forever. But why are we cutting down forests at this alarming rate?
• Large-scale deforestation happens when huge areas of forest are cleared for human activities. Unlike small-scale logging, this involves removing entire forest ecosystems - sometimes areas larger than entire countries. The three main drivers are surprisingly everyday: the beef on your plate, the rice in your cupboard...
• Cattle ranching is the leading cause of deforestation worldwide, responsible for about 80% of Amazon rainforest destruction. Here's why cattle need so much space.
• One cow needs approximately 2-5 hectares of grassland for grazing. When you multiply this by millions of cattle, the land requirements become enormous. In Brazil alone, cattle ranching occupies an area larger than the entire United Kingdom.
• Trap: Many students think cattle can graze in existing forests. Actually, cattle need open grassland - the trees must be completely removed first. This is why cattle ranching causes such extensive deforestation.
• Rice feeds over half the world's population, but growing it requires specific conditions that often conflict with forest ecosystems.
• Rice cultivation needs flat, flooded fields called paddies. Forests grow on varied terrain with complex drainage systems. To create rice paddies, forests must be cleared and the land levelled. In Southeast Asia, vast areas of tropical forest have been converted to rice fields to meet growing food demands.
• The scale is staggering. Indonesia has cleared over 6 million hectares of forest for rice production - an area larger than Ireland. Each hectare can produce enough rice to feed about 19 people for a year, but at the cost of losing irreplaceable forest ecosystems.
• Biofuels sound environmentally friendly, but growing the crops needed creates a surprising problem for forests.
• Renewable fuels made from biological materials like palm oil, soy, or sugar cane. Used as alternatives to fossil fuels in transport and energy production.

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