Thailand promoted Leucaena trees for fodder and reforestation, but scientists found that the fast-growing species is suppressing the natural regeneration of native forests

A country plants trees with good intentions, hoping to heal degraded land and feed livestock. Decades later, scientists discover those same trees are quietly choking out the forest they were meant to help. That's exactly what's playing out in Thailand with a plant called Leucaena leucocephala, and it's a story that says a lot about how even well-meaning environmental fixes can backfire.

A tree with a good reputation gone wrong