In 1800, the highlands of Sri Lanka had some of the most biologically diverse primary tropical rainforest ecosystems in the world. By 1900, only a few craggy corners and mountain caps had been spared the fire stick. Highland villagers, through the extension of slash-and-burn agriculture, and British managers, through the creation of plantations-first of coffee, then cinchona, and finally tea-had removed virtually the entire primary forest cover. Tropical...