Why in News ?

Amazon Changing From Forest to Savanna latest report. As much as 40% of the Amazon risks crossing a tipping point from rainforest to savanna as greenhouse gas emissions reduce the rainfall needed to sustain its unique ecosystem.

What is Savanna ?

• Savannas are characterized by the coexistence of trees and grasses and occur largely in the seasonal tropics between the equatorial rainforests and mid-latitude desert ecosystems.
  • Savannas grow in tropical regions 8° to 20° from the Equator.
• Savannas represent one of the largest extensions of land in the world.
• Tropical savannas occur in the seasonal tropics of Africa, South America, Asia and Australia.
• Mean annual precipitation is generally 80 to 150 cm and mean monthly temperatures are about 10 to 20 °C.
  • Savannas may be subdivided into three categories wet, dry, and thornbush depending on the length of the dry season.

Forest To Savanna Shift

• Rainfall in the Amazon is so low already that up to 40% of it risks tipping over into a savanna-like environment, with far fewer trees and far less biodiversity.
• Rainforests normally create their own rainfall through water vapour, sustaining tree levels and even extending their reach.
  • When precipitation levels fall, the forests begin to disappear.
  • As forests shrink, we get less rainfall downwind and this causes drying, leading to more fire and forest loss: a vicious cycle.
• Many of the world’s rain forests would struggle to grow back once lost, leading to a far wider savanna-like mix of woodland and grassland.
• Amazon loss, the team found that the forest in the Congo basin was at risk of changing to savanna, and that large swathes would not grow back once gone.
• Importance of Rain forest
  • Rainforests on all continents are very sensitive to global change and can rapidly lose their ability to adapt.
  • Once gone, their recovery will take many decades to return to their original state and given that rainforests host the majority of all global species, all this will be forever lost.
  • This can have significant knock-on effects on nature with the loss of tropical habitats as well as the climate as shrinking forests lose their ability to absorb manmade emissions.
  • It also increases the risk of fire.

How to protect Rain Forest ?

• Deforestation of tropical rainforests has a global impact through species extinction, the loss of important ecosystem services and renewable resources, and the reduction of carbon sinks.
• A significant portion of deforestation is caused by poor farmers, Developmental projects and related human activities.
• Major to do are 
  • Reduce the carbon foot print.
  • Increasing the protected areas and proper implementation of afforestation.
  • Recognising the Rights of Indigenous Peoples
  • Reducing the Use of Tropical Timber

Source : The Hindu

Topic

GS III : Conservation, environmental pollution and degradation, environmental impact assessment

Current Affairs Compilation : 6 October 2020