A Spatiotemporal Model of Shifting Cultivation and Forest Cover Dynamics

Shifting cultivation is the primary means of livelihood for subsistence farmers throughout the humid forests of the tropics. Sustainable use of the resource base as a source of fertile land for cultivation requires long periods of fallow and the ability to move the zone of active cultivation from one location to another over time. At the individual patch or field level, shifting cultivation is essentially a resource extraction problem somewhat akin to a pulse fishery – intensive use of the stock of soil fertility for a short period followed by a long idle period to allow regeneration of the stock. This paper describes a spatiotemporal model of resource extraction adapted to the use of forest resources by shifting cultivators. It focuses on the theoretical issues related to modeling shifting cultivation, uses the analytical model to motivate an estimable empirical model, and concludes with a demonstration of the concept in a simulation model of subsistence agricultural production in southern Cameroon, highlighting the key insights gained through use of a spatiotemporal household model. In particular, a stated preference approach to the modeling of decision-making identifies individual preferences and spatial pathdependency as important sources of shortened fallows and resource degradation.