Key Takeaways
- Brazilian scientists are artificially starving Amazon trees of water to test forest resilience limits
- The southeastern Amazon region faces the highest tree mortality rates and most intense human pressure
- 10-47% of Amazon forest could degrade into other ecosystems by 2050 according to recent studies
- Researchers warn both climate change and immediate human destruction threaten the rainforest’s survival
Scientists in Brazil are conducting a groundbreaking experiment to understand how much drought the Amazon rainforest can withstand before reaching irreversible tipping points. In Querencia municipality, hundreds of plastic panels capture half the rainfall from a hectare of forest, creating an artificial drought scenario predicted by climate models.
The “Limit Drought” experiment monitors 61 trees like hospital patients, measuring sap flow, respiration, temperature and carbon dioxide levels with solar-powered equipment. “It’s like someone was taking measurements of your pulse and breathing every day,” said David Galbraith of Leeds University, one of the lead researchers.
The team tracks tree trunk sizes, soil conditions from 6-meter deep holes, and falling leaves while AI drones create 3D forest models. This southeastern Amazon region, already transitioning toward savanna, faces intense pressure from agriculture and climate change.
Amazon Resilience Under Threat
Across the Amazon, climate change, deforestation and forest degradation are creating drier conditions that scientists fear could push parts of the region beyond recovery. “The forest here is on the frontline of climate change,” said Antonio Carlos Lola da Costa of Brazil’s Federal University of Para.
Recent research shows alarming trends:
- The Amazon suffered four severe droughts this century, fueling record wildfires in 2023
- 2024 saw the highest atmospheric CO2 spike since modern measurements began
- Drought-reduced forests and warmer oceans are losing capacity as carbon sinks
Three Decades of Forest Monitoring
Researchers Ben Hur and Beatriz Marimon have measured forest plots along the deforestation frontier for 30 years. “We started measurements in 1994, and 15 years later, we became scared because so many trees started to die,” said Beatriz.
Their data, published in a 2020 Nature paper, revealed the southeastern Amazon has the highest tree mortality rate in the entire rainforest. In Nova Xavantina, they monitor ancient trees showing signs of collapse.
“That one is over 300 years old, and it won’t last another century. These are the first ones to die,” Ben Hur said, pointing to a rotting 30-meter tree. Extreme drought makes trees vulnerable to termites and diseases, increasing mortality in subsequent dry periods.
Glimmers of Hope Amid Crisis
While the situation appears dire, some research offers cautious optimism. A northern Amazon drying experiment showed forest adaptation after initial biomass loss – trees became shorter with less canopy, but the forest persisted.
However, the southeastern experiment faces harsher conditions in areas fragmented by soybean fields and cattle pastures. Beatriz Marimon emphasizes that immediate human destruction poses a greater threat than gradual climate change.
“People are so focused on a climate tipping point that they forget about the human tipping point: the crawler tractor that tears everything down,” she warned. “Not in 1,000 years will a tractored forest be the same.”
