伐らない焼畑--カメルーン東南部の熱帯雨林帯におけるカカオ栽培の受容にみられる変化と持続 (特集 地域研究の前線)

Abstract

Cacao (Theobroma cacao L.) is an important cash crop for small-scale Bangandou farmers living in forested area of Cameroon. In this region, cacao is usually grown under the shade in fi elds of selectively thinned natural forestland. This study aims to clarify how the cacao-growing system has been integrated into the Bangandou's subsistence slash-and-burn agriculture and examines its role in their livelihood. Bangandou people favor establishing new cacao fi elds in primary forests or old cacao fi elds because the shaded condition is easier to create in such vegetation. When the land is cleared, a larger number of trees are left in the cacao fi elds than in the fi elds of food crops only. This strategy of leaving more trees saves the labor for felling, and attracts people to clearing the primary forests, which would otherwise require larger labor forces. Cacao seedlings are planted in a newly cleared fi eld, mixed with a variety of food crops during the initial several years, and grow while farmers harvest the food crops from the same fi elds. Unlike the food crop fi elds, weeding is indispensable to cacao growing, but it is so laborious that parts of the planted cacao fi elds often become covered with thick bush regrowth. Although these areas have to be abandoned, people may clear them for replanting after a few years. Analyses of crop rotation and vegetation change in the cacao fi elds show that the fundamental elements of their farming system have remained largely unchanged by the introduction of cacao growing, in which the same principle of shifting cultivation is adopted for the new crop. This type of agriculture also ensures the stable production of food crops and acts as a buffer against unstable cacao prices and productivity.