Amazon Trees Growing Larger as CO2 Levels Rise, Study Finds

New research highlights a steady increase in tree size across the Amazon, linked to higher atmospheric carbon dioxide.

The average size of trees in the Amazon rainforest has been steadily increasing, with trees growing by more than three per cent every ten years, according to a new study. Published on September 25 in the journal Nature Plants, the study, titled ‘Increasing tree size across Amazonia’, was conducted by an international team of around 100 scientists from over 60 universities worldwide, including institutions in South America and the United Kingdom.

Although monitoring periods varied—some spanning as long as 30 years—the researchers found that, on average, trees increased in diameter by about 3.3 per cent each decade. Typically, in undisturbed old-growth forests, the average tree diameter remains roughly the same as new saplings replace fallen mature trees. However, in the Amazon, this trend has shifted.

Scientists attribute this growth surge to rising atmospheric carbon dioxide (CO2) levels, which have increased by nearly 20% over the past three decades. The additional CO2 enhances photosynthesis through a phenomenon known as the carbon fertilisation effect, boosting tree growth.

The findings are significant because larger trees can absorb more carbon than smaller ones, offering potential benefits in the fight against climate change.

The Amazon rainforest, the world’s largest tropical forest, spans nine countries in South America: Brazil, Peru, Colombia, Bolivia, Ecuador, French Guiana, Guyana, Suriname, and Venezuela, with nearly 60% of the forest located in Brazil.

(Source: IE)