Shifting cultivation, also known as swidden or slash-and-burn in the scientific literature and by countless local names where it is practiced, is one of the oldest and most widespread agricultural land use systems on Earth. For decades, it has been an important topic of research for geographers who study indigenous and peasant forest dwellers, as well as deforestation and land degradation in the tropics. Shifting cultivation covers an estimated 7.7 million square miles (20 million square kilometers) of arable land and supports 270 million people, or 4% of the global population in 2008. Most shifting cultivators inhabit sparsely settled tropical forests in Africa, South and Southeast Asia, Oceania, and the Americas. In terms of land area, shifting cultivation is most extensive in Brazil, the Congo, ...