Thought Question: How do you think you can help protect the environment in your own community? Scientists in the Amazon rainforest are hoping to use trees like a network of spies. They believe the trees can help them root out illegal gold mining in the region. Modern gold mining techniques can harm rainforest ecosystems. That's especially true of unlicensed miners seeking to strip the earth of its gold. That’s because they use mercury. It's an element that is toxic to humans and wildlife. Mercury binds to gold. So miners will soak the ground in the Amazon with liquid mercury. When it comes into contact with gold, it forms larger chunks known as amalgams. Miners are able to collect these chunks, then heat them. Mercury has a lower melting point than gold. That means it will drain away from the gold specks. Miners can then sell the gold that's left behind. The process poisons the soil and releases clouds of toxic gas. Mercury gas can harm wildlife and humans. It is also absorbed by some types of trees. As a result, researchers can find where mining has occurred by looking at core samples of those trees. They can find traces of mercury stored in the trees’ rings as they grow. "Trees can provide a widespread and fairly cheap network of biomonitoring,” Jacqueline Gerson told Phys.org. That's because the trees keep "a record of mercury concentration within tree bolewood.” Gerson is a professor at Cornell University. Gerson published her findings in the journal Frontiers in Environmental Science. She hopes that the tree-spy technique allows police to better trace and prevent illegal gold mining. Gif of trees in Amazon rainforest from GIPHY.
