| Project/Area Number |
63043059
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| Research Category |
Grant-in-Aid for Overseas Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Field Research |
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| Research Institution | Tokyo Metropolitan University |
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Principal Investigator |
KADOMURA Hiroshi Prof., Fac. of Sci., Tokyo Metropolitan Univ., 理学部, 教授 (80087064)
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| Co-Investigator(Kenkyū-buntansha) |
DONGMO J.-L. ヤウンデ大学, 人文社会学部, 教授
IMAGAWA Toshiaki Research Fellow, Fac. of Sci., Tokyo Metropolitan Univ., 理学部, 助手 (70193670)
TAKEUCHI Kazuhiko ASS. Prof., Fac. of Agr., Univ. of Tokyo, 農学部, 助教授 (90112474)
YAGI Hisayoshi Ass. Prof., Fac. of Agr., Univ. of Tokyo, 農学部, 助教授 (80191089)
TAMURA Toshikazu Ass. Prof., Col. of General Education, Tohoku Univ., 教養部, 助教授 (00087149)
DONGMO Jean-Louis Prof., Fac. of Hum. & Soc. Sci., Univ. of Yaounde
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| Project Period (FY) |
1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1988: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | Savannization Processes / Desertification Processes / Environmental Changes / Tropical Rain Forest / Woodland / Savanna / サバンナ / ステップ |
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| Research Abstract |
The object of the project is to make up comparative and chronological studies of natural and anthropogenic savannization processes in tropical Africa. The results obtained from the 1987 season field work can be summarized as follows.
1. Over much of tropical Africa, in the last 100 years both savannization and desertification processes have been accelerated, in particular during drought periods of mid-1910s and since late 1960s.
2. In Zambia, the disappearance of dry evergreen forest can dates back to 400-800 years ago when the Later Iron age people began shifting cultivation. Now the dry forest exsits only on the Kalahari sands where man's impact has been least. In contrast, intensive interfrence with the forest by repeated burning and cutting has resulted in "miombo" woodlands, a representative landscape in the southern savanna zone, consisting of short and sparse woody vegetation which grows on soils with poor organic content and physical properties.
3. In northern Cameroon it is assumed that long-term, natural savannization and desertification began somewhat after 4500 yr B.P. correspondeing to the over all climatic aridification in tropical Africa.
4. Although the impact of past and and recent climatic changes remains unanswered, the major cause of the savanna landscape on the north of the Sanaga can be attributed to recent agricultural activities. In the last 20 years, in the Oku Mountains, West Cameroon, forests have been accelerately burned and cleared to make way for cultivation of food crops. The chronological make up of the origin of the Grassfields in the West Cameroon Highlands calls for further research.
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