Research by Abra Atwood and colleagues finds why the Amazon forest isn’t healing when gold miners move on. The team used drones, soil sensors & underground imaging to assess the damage of suction mining. They found the land isn’t cursed by poison in the soil. It’s lack of water.
Gold mining is ripping the Amazon apart. “In suction mining, topsoil is washed away into ponds and surrounding forests and rivers (leading to further forest and river degradation), leaving gold-bearing sand,” write the authors. “Suction mining requires large volumes of water, leading to a landscape of deep (2–7 m) mining ponds and sand in place of rainforest and clay-rich soils.” This hydraulic strip mining has destroyed 95,750 hectares of Amazon rainforest since 1980, the same area as 135,000 football pitches.
The team used electrical resistivity imaging to track water movement. They found that the sand piles act like sieves. Rainwater drains through them up to 100 times faster than in undisturbed soil. These areas also dry out nearly five times faster after rain, creating parched patches.
While the sand piles don’t hold on to the rain of the tropics, they certainly hold on to the heat. On exposed sand piles, surface temperatures reached as high as 60°C (145°F). “It’s like trying to grow a tree in an oven,” said one of the authors in a press release.
Drone-mounted thermal cameras showed how barren ground baked under the sun while nearby forested areas and pond edges stayed significantly cooler. “When roots can’t find water and surface temperatures are scorching, even replanted seedlings just die,” said Atwood.
In the paper, they tackle both problems: “We specifically suggest lowering the elevation of tailing piles and backfilling ponds to improve revegetation success.” Filling ponds will help seedlings get closer to water, and levelling the piles will help diminish the heat reservoirs.
The authors say that while natural erosion might eventually allow forest to reclaim the mines, nature will be slow. Other researchers have estimated these scars will take centuries to recover. Atwood et al conclude that humans need to take responsibility to speed up the process of recovery.
Atwood, A., Ramesh, S., Amaya, J.A., Cadillo-Quiroz, H., Coayla, D., Chen, C.-M. and West, A.J. (2025) “Landscape controls on water availability limit revegetation after artisanal gold mining in the Peruvian Amazon,” Communications Earth & Environment, 6(1), pp. 1–10. https://doi.org/pp9k.
Cross-posted to Bluesky & Mastodon.
Cover: Example of suction mining process in Balata (photo credit: A.J. West, Sept. 2024), sourced from Atwood et al 2025.
The post The search for gold risks losing treasure appeared first on Botany One.
