Amazon Rainforests

Amazon Rainforests

News: A study published recently says that a significant part of the Amazon rainforest has been heading towards a tipping point since the early 2000s. It may be losing its ability to bounce back from extreme events such as drought or fire, threatening to become a dry savanna-like ecosystem.In this study, researchers analyzed 30 years of satellite data to understand the resilience of the rainforest and how it has changed over the years.The latest findings are consistent with the accumulating evidence that the twin pressures of climate change and human exploitation of tropical forests are endangering the world's largest rainforest, which is home to one out of every 10 species known to science.

Savannah-Like Ecosystem:
• The Savannah ecosystem is a tropical grassland with warm temperatures year-round and with its highest seasonal rainfall in the summer.The savanna is characterized by grasses and small or dispersed trees that do not form a closed canopy, allowing sunlight to reach the ground.
• The largest areas of savanna are found in Africa, South America, Australia, India, the Myanmar (Burma)– Thailand region in Asia, and Madagascar.

Latest findings:
• There are signs of a loss of resilience in more than 75% of the forest, with trees taking longer to recover from the effects of droughts largely driven by climate change as well as human impacts such as deforestation and fires.A vicious cycle of damage could trigger 'dieback”.Dieback is a condition in which a tree or shrub begins to die from the tip of its leaves or roots backwards, owing to disease or an unfavourable environment.
• While it's not clear when that critical point might be reached, the implications for climate change, biodiversity and the local community would be 'devastating'.A previous study predicted that a tipping point would occur when the rainforest witnesses roughly 20-25% of deforestation.

Causes:
• It totalled 430 square kilometers in January 2022, five times higher than the same month last year.Around a fifth of the rainforest has already been lost, compared to pre-industrial levels.This loss will affect the amount of rainfall. Trees take up water through the roots, releasing it into the atmosphere, influencing precipitation over South America.
• Increasing temperatures due to human-induced climate change and deforestation are pushing the rainforest to transform into a carbon source: Places that release more CO2 than they absorb.The researchers warn that the forests could release vast amounts of CO2 if they partially transform into dry habitats.
• Human land-use activities — direct removal of trees, construction of roads, and fires — could be another contributor. It has been on the rise since 2010.