LANDSCAPE AND DISEASES. THE MIDDLE HOLOCENE SAHARA: A DEVELOPMENT OF CULTURAL LANDSCAPE AS RESULT OF A RISK-ORIENTED BEHAVIOUR
E. SCHULZ
SUMMARY. - Landscape and Diseases. The Middle Holocene Sahara: A Development of Cultural Landscape as Result of a Risk-Oriented Behaviour. Interrelationships and interdependencies within the traingle: man-landscape- disease may be explained by a risk oriented behaviour of man. A special case of such a risk management is given by the evolution of cultural landscape during the Holocene in the present day South Sahara. Southward moving cattle keepers were confronted in the former contact Sahara-Sudan to a landscape, which presented deadly risks. These were diseases like trypanosomiasis or onchochercosis, which formerly were part of regional zoonosises. They could not be counteracted by an auto-imummunisation or by traditional medical treatment. Finally it was a boundary, which only allowed retreat or radical and definite transformation of the landscape system itself. The evolution of the former sudanian savannas into an open landscape with only few breeding places for tse-tse-flies represented a development of a cultural landscape. It evolved parallel to a climatic deterioration. Interference with use of fire, pasture and later on agriculture as well as metal production remained severe and hardly allowed any recovering of the plant cover.