Inside one of the remaining old plantations, it's easy to see that they have become a biodiversity desert. As I step into the forest, twigs snap loudly. The trees are planted so closely the sunlight is a dim greyish tinge, and the plantation floor is littered knee-high with bone-dry, brittle debris. It is eerily quiet and stuffy – I can hear no animals, and see few other trees, shrubs or fungi anywhere on the forest floor. "This is a monoculture," says Jones. "It's rare to see many birds in here."