Deforestation in the rainforest involves removing trees and using land for another purpose. The global rates of rainforest deforestation are:
- 2.47 acres (1 hectare) per second: equivalent to two U.S. football fields;
- 150 acres (60 hectares) per minute;
- 214,000 acres (86,000 hectares) per day which is an area larger than New York City; and
- 78 million acres (31 million hectares) per year which is an area larger than Poland.
The image below shows some of the causes and effects of deforestation in the Amazon Rainforest.
How do humans affect the rainforest
Slash and burn
Most clearances are still by the local people and tribes needing land on which to grow crops. They clear the forest by ‘slash and burn’. Vegetation is cut down and then burned. The ash acts like a fertiliser adder nutrients to the soil. When the soil begins to turn infertile (usually after 3-5 years) the people move on. This is called shifting cultivation. It is a sustainable method of farming in the rainforest. It ensures the forest will recover.
Commercial logging is the major cause of primary rainforest destruction in South East Asia and Africa. World wide, it is responsible for the destruction of 5 million ha. per year. Logging roads enable landless people to enter the forest. In Africa, 75% of land being cleared by peasant farmers is land that has been previously logged.
Ranching is a major cause of deforestation, particularly in Central and South America. In Central America, two-thirds of lowland tropical forests have been turned into pasture since 1950.
There are nearly 3 million landless people in Brazil alone. The government has cleared large areas of the Amazon Rainforest and encouraged people to move there. The scheme has not been successful. Farmers stay on the same land and attempt to farm it year after year. Nutrients in the soil are quickly exhausted as there is no longer a humus layer to provide nutrients. The soil becomes infertile and nothing will grow.
The mining of iron ore, bauxite , gold, oil and other minerals have benefited many LEDCs. However, it has also devastated large areas of rainforest e.g. The Amazon.