Threats to the tropical rainforest

The tropical rainforests of the Amazon Basin face the threat of deforestation. Deforestation is happening for the following reasons:

  • Farming - large areas are cleared for pastoral farming. As the global demand for meat has increased, many cattle farms have opened in the Amazon Basin for beef farming. Arable farming is also responsible for the loss of tropical rainforests as many farmers are clearing land to grow cash crops, such as soya beans, often in monoculture plantations.
  • Logging - tropical rainforests are cut down so that valuable trees like mahogany can be accessed and sold for timber to make furniture. Other trees are cut down for making paper products.
  • Mining - the Amazon Basin is rich in natural resources such as iron ore, copper, tin, aluminium, manganese and gold. This has led to the development of mines which results in the clearance of tropical rainforest. The Carajas mine in Brazil is the world's largest iron ore mine.
  • Roads - the construction of access roads for farmers, loggers and miners results in large parts of the tropical rainforest being destroyed.
  • Hydroelectric power (HEP) - The creation of HEP stations in the Amazon Basin has resulted in large areas of forest being flooded to create the reservoirs and dams. The flooding of the Balbina dam in Brazil resulted in the loss of 920 square miles of tropical rainforest.
  • Population - population growth has resulted in the loss of tropical rainforest as land is cleared for subsistence 'slash and burn' farming, or to build houses and infrastructure.
  • Tourism - camps and lodges are being built to satisfy the demands of increased 'eco-tourism' visitors.

Impacts of tropical rainforest loss

The impacts of the deforestation of the Amazon Basin include the following.

Soil erosion

Once the land is cleared of rainforest vegetation the soil is left bare. When it rains, the nutrients in the soil are washed away. The nutrient cycle stops because there are no plants or trees shedding leaves to replace the nutrients in the soil. The soil is no longer able to support plant life because it is not fertile. The roots of plants and trees no longer hold the soil together so it is easily eroded.

The rainforest nutrient cycle: trees shed leaves all year round, decaying vegetation decomposes rapidly, nutrients enter the soil, shallow roots take up the nutrients, trees grow rapidly.This rainforest nutrient cycle stops with deforestation

Loss of biodiversity

Many different species of plants and animals die because of deforestation. As plants and animals are closely connected through the food web, deforestation this reduces the biodiversity, or variety of species found in the tropical rainforest.

Climate change

The trees and plants of the Amazon Basin absorb carbon dioxide during the process of photosynthesis. If there are fewer trees and plants, due to deforestation, then less carbon dioxide is removed from the atmosphere. In this way deforestation contributes to global warming and therefore climate change.

Economic development

The creation of mines, farms and roads - which caused deforestation - has also led to economic development. The money created from these enterprises allows a country to generate foreign income, which can then be used to pay off debts or be invested in further development projects.