Forests in Asia and throughout the tropical world are being rapidly transformed through slash-and-burn. Increasing population pressure has made this ancient system unsustainable in many areas. In lesser populated areas slash-and-burn, or shifting agriculture, is less problematic and perhaps even the only viable form of utilisation of indigenous peoples natural resources.
Shifting cultivation is a form of “sequential agroforestry”, where crops and trees take turns in occupying the same land. Two essential aspects necessitate this sequential system from the farmer’s viewpoint; nutrient recycling and weed management. Probably the most widely known system of this type is traditional swidden cultivation, or slash-and-burn agriculture, which is the most extensive farming system in the humid tropics.