Why Amazon is at risk of changing from Forest to Savanna?

A team of Europe-based scientists, in their  journal Nature Communications, have published that about 40% of the Amazon risks changing from rainforest to savanna. They have stated that, the forest is not getting enough rainfall to sustain its ecosystem because of greenhouse gas emissions.

Highlights

  • The team used the latest atmospheric data to study how tropical forests might respond to changing rainfall levels.
  • They studied the effect of continued emissions from burning fossil fuels till the end of the century from now.
  • They found that rainfall in the Amazon is so low and up to 40% of it risks changing into a savanna-like environment that will comprise of far fewer trees and far less biodiversity.

Background

Forests are usually very sensitive to changes affecting the rainfall for extended periods. The trees may also  die off if there is no rain for long. This can severely effect nature with the loss of tropical habitats and climate. This is because, shrinking forests loses their ability to absorb man-made emissions. This also increases the risk of such fires that amazon went through in recent past.

Vicious cycle

The rainforests usually create their own rainfall through water vapour thus sustain tree levels and extends their reach.  But when precipitation level falls, the forests begin to disappear. As forests begin to disappear, there is less rainfall downwind. This causes drying of the forests thus leads to more fire and forest loss.

Causes

  1. In the tropical regions, there is not enough rainfall to sustain a rainforest at many places.
  2. Forests are also shrinking back because of lack of moisture.
  3. Growing global greenhouse emission and climate change is another reason for this instability in the forest ecosystem.
  4. In the amazon basis, forest gets rainfall through water vapor mostly as opposed to stable forests of Indonesia and Malaysia because the rainfall is more dependent on ocean around them.

Concerns

World’s rainforests would struggle to grow back once they are lost and they will change into a wider savanna-like mix of woodland and grassland.