Tree that bleeds toxic metal

Team Udayavani, Apr 25, 2021, 3:41 PM IST

In an unusual event, a tree that grows on the island of New Caledonia in the South Pacific is bleeding a highly toxic metal.

When the bark of Pycnandra acuminata tree is cut, it bleeds a bright blue-green latex that contains up to 25% nickel, which is highly poisonous to most plants in more than tiny amounts.

Around 700 plant species have unusually high levels of metal, which is nickel in most cases. These are called hyperaccumulators.

It is said that if these metal-containing plants are dried and burned to ash, they can yield extremely rich, high-grade metal ore, generating far less pollution and using far less energy than needed in conventional mining.

Dr. Anthony van der Ent, a researcher at the University of Queensland who has been studying the tree said that Pycnandra acuminata is a large (up to 20m tall) rare rainforest tree, restricted to remaining patches of rainforest in New Caledonia.

He further added that as a test subject it is challenging because it grows slowly and it takes decades to get it to produce flowers and seeds. As a result of mining activities and bush fires, it is threatened by deforestation.

He informed that these plants are found on naturally metal-enriched soils and the evolution of hyperaccumulation has evolved many times over in very different families, and likely has taken millions of years

It is a mystery how these plants manage to tolerate poisonous metals in such huge amounts without killing themselves.