摘要：Beforona is a mountainous region in eastern Madagascar, where slash-and-burn cultivation (tavy) has been practiced for several generations to produce rice, the staple food of the Malagasy people. This system of cultivation has long been unsustainable (deforestation, erosion, loss of soil fertility, etc). Other types of cultivation considered more sustainable were inventoried in a study, particularly the irrigated rice field and traditional agroforestry system known as tanimboly found in the valleys. On the basis of research results, data were incorporated into a Geographic Information System (GIS) to elaborate descriptive models using different parameters related to this farming system. Spatial distribution of tanimboly shows that more than 90% is concentrated along small streams, in concave areas, and not on slopes and hillsides. Tanimboly becomes scarcer as the distance from the forest edge approaches 2 km, and surface areas are drastically reduced in proportion to distance from roads. GIS and regression models made it possible to identify potential areas for tanimboly. Relations between the various parameters were calculated using logistic regression functions to predict occurrence of the tanimboly phenomenon in nonsampled zones. It appears that farming strategies are particularly influenced by infrastructure.
