ABSTRACT
The study of environmental energy flow Is a method which can be used to evaluate the human exploitation of an environment. The sampling zone of the human energy flow project was purposely located around the study site of the Tunsian PreSaharan project. An interruption in energy flow threatens the survival of man and other organisms in the ecosystem. From the results of the ecosystem study, it was anticipated that less destructive land use alternatives could be proposed which would be compatible with the subsistence needs of the local inhabitants. The harvesting of firewood, of plants for animal feed, of wood or branches for building material, and of other non-food items is studied in order to assess the total use of an ecosystem by the human population within it. Part of the purpose of the research in Southern Tunisia was to determine the human contribution to the processes of soil and vegetation deterioration called desertization.
