🌾 Subsistence farming
Poor families clear small plots by cutting and burning trees ("slash and burn"). The ash feeds the soil for a few years. When the soil is used up, they move on and clear more forest.
Tropical Rainforests » Causes of Deforestation in the Amazon
What you'll learn this session
Study time: 30 minutes
AQA spec: 3.1.2.2
- How the rate of deforestation in the Amazon has changed over time
- The causes of deforestation: farming, logging, roads, mining, energy, settlement and population growth
- How these causes link together
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Unlock This CourseDeforestation and the Amazon
Cattle ranching is a major cause of deforestation in the Amazon
Large areas of tropical rainforest are being cleared today. This lesson is a case study of the Amazon rainforest in South America. It is the largest rainforest on Earth and about 60% of it lies in Brazil.
Key terms:
- Deforestation: the cutting down and removal of forest on a large scale.
- Subsistence farming: growing food or keeping animals mainly to feed your own family.
- Commercial farming: growing crops or keeping animals to sell for profit.
- Logging: cutting down trees to sell the wood (timber).
- Mineral extraction: mining or digging up valuable rocks and metals from the ground.
- Settlement: people moving to an area and building homes, farms and towns.
Changing rates of deforestation
The rate of deforestation in the Amazon has not stayed the same. It has gone up and down.
- Rising: from the 1970s, clearance sped up as roads and farms spread. In 2004 Brazil cleared about 28,000 km2 of Amazon forest in one year. That is more than the size of Wales.
- Falling: after 2004 the Brazilian government used satellites, fines and police to cut illegal clearance. By 2012 the yearly rate had fallen to about 4,500 km2.
- Rising again: from about 2013 the rate crept up. In 2021 it was over 13,000 km2, nearly three times the 2012 figure.
So the rate changes with government policy, money and demand for products. The forest is still being lost in every one of these years.
Causes of deforestation
Logging is one cause of deforestation in the Amazon
There is no single cause. Many things work together. Some people clear the forest to survive. Others clear it to make money.
Farming
🐄 Commercial farming
Large companies clear huge areas for cattle ranches and for soy beans. Cattle ranching is the biggest single cause of clearance in the Amazon. Much of the soy is sold as animal feed.
Logging
Valuable hardwood trees, such as mahogany, are cut down and sold for furniture and building. Loggers make tracks to get the trees out. These tracks open up the forest to more people. Some logging is illegal and hard to control in such a huge area.
Road building
Roads, such as the Trans-Amazonian Highway built from the 1970s, were cut through the forest to link it to the rest of Brazil. Roads make it possible to reach new areas. Farmers, loggers and miners follow the road and clear forest on both sides. Roads are often the first step in deforestation.
Mineral extraction
The Amazon has iron ore, gold and other minerals. Mines such as Carajas in Brazil need large areas of forest cleared for the mine, the waste and the roads and railways that carry the ore out.
Energy development
Fast rivers can be used to make hydroelectric power (HEP). Dams, such as Belo Monte on the Xingu River, flood large areas of forest behind the dam. More forest is cleared for the power lines and access roads.
Settlement and population growth
From the 1970s the Brazilian government encouraged people to move to the Amazon. Landless families from crowded cities and poor regions moved in. They cleared forest for homes, farms and new towns. As the population has grown, more land is needed for housing, food and jobs, so more forest is cleared. Brazil's growing population also raises the demand for farm products, timber and energy.
How the causes link together
Roads open up the forest. Settlers, farmers, loggers and miners then arrive. A growing population needs more food, homes and energy, which leads to more roads, farms and dams. One cause makes the next one easier.
Common mistakes
Saying "people are cutting down trees" is not enough for marks. Name the cause, then explain how it clears the forest. Also, do not mix up subsistence farming (feeding the family) with commercial farming (selling for profit). Finally, do not write about the impacts of deforestation here. They are a separate topic.
Exam-style question
Using a case study of a tropical rainforest, explain two causes of deforestation. [4 marks]
Model answer
Cause 1: Commercial farming (1). In the Amazon, large areas of forest are cleared for cattle ranches and soy farms to make money from selling beef and animal feed (1).
Cause 2: Road building (1). Roads such as the Trans-Amazonian Highway open up the forest so settlers, loggers and miners can reach it and clear land along the road (1).
Exam tip
For "explain" questions, name each cause, then add a "so" or "because" to show how it leads to the loss of trees. Use a place name from the Amazon in each answer.