著者

OYAMA S.

出版者

京都大学

雑誌

African Study Monographs (ISSN:02851601)

巻号頁・発行日

vol.17, no.3, pp.101-116, 1996-10

被引用文献数

3

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In the miombo woodland of northern Zambia, the Bemba have practiced a unique shifting cultivation called citemene system, tree branches are collected into a garden area from the surrounding tree-cutting area and burnt. This study clarifies the impact of citemene system on the environment by analyzing 1) ecological fallow periods, 2) effects of burning on vegetation, and 3) optimum fallow periods in both the tree-cutting area and the garden area. 1) In the tree-cutting area, a fallow period of 30 years is required to reach a proto-climax stage of the woodland after cutting and burning trees (ecological fallow periods). In the garden area, fallow period should be more than 50 years. 2) At the early stage of regeneration, the miombo woodland species dominated the tree-cutting area, while species of the open woodland and chipya forest dominated in the garden area. The difference in vegetation between the two areas tended to become reduced as the fallow period increases. 3) Optimum fallow periods which may supply enough biomass for finger millet production and make sustainable utilization of miombo woodland possible, were estimated to be 16 years for the tree-cutting area and about 35 to 40 years for the garden area. A fallow period shorter than the optimum fallow period, is likely to diminish wood biomass and yield of finger milet. To avoid such situations, the Bemba have traditionally moved villages or built seasonal dwelling for citemene cultivation which are far from the settlement.