Rainforest Roulette: What Happens When the Amazon Goes Dry? Scientists Have Answers

Image Source: Mongabay

A 24-year drought simulation in the Amazon rainforest has uncovered critical insights into how the ecosystem responds to prolonged dryness. Conducted by Brazilian and British scientists in the Caxiuana National Forest, the Esecaflor project diverted 50% of rainfall from a one-hectare plot using transparent panels, revealing both vulnerabilities and unexpected resilience.

Key Findings

Biomass Collapse: The experimental area lost approximately 40% of its vegetation biomass, with large trees dying off first. This shifted the rainforest from a carbon sink to a carbon emitter before stabilizing.
No Savanna Transition: Contrary to earlier predictions, the drought-stressed forest did not transform into a savanna, retaining its structural integrity despite significant biomass loss.
Human Impact: NASA studies cited in the research highlight that human activities, including deforestation and greenhouse gas emissions, have intensified atmospheric dryness, exacerbating drought conditions.

Implications for Climate

The Amazon stores carbon equivalent to two years of global emissions. Biomass loss releases stored carbon, accelerating climate change. Recent El Niño events have compounded these effects, causing record droughts, wildfires, and wildlife die-offs, such as river dolphins in 2023–2024.

Next Steps

In November 2024, researchers removed the panels to study forest recovery. Scientists are now monitoring whether the ecosystem can regenerate to its pre-drought state. The project, ongoing since 2000, has no set end date, reflecting the long-term commitment to understanding Amazon resilience.

Source: Associated Press