Savannization Processes in Tropical Africa - TAGELAQP 88/89

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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.