Abstract EN:

This thesis proposes a theoretical framework for studying the society-environment relationship in a systemic perspective especially in the context of social systems that are closely dependant on their local environment, as is still the case for most rural communities in developing countries. Traditional analytical, quantitative approaches (using linear causalities) generally fail to explain the complexity of the relation between a society and its environment. This dissertation employs a dynamic interactive socio-ecological system (SES) model which represents the organization of the interface that links any society to its natural environment. Focusing on the institutional aspect of this interface, i argue that the relation between institutional design and ecosystemic properties is critical for sustainability. Sustainable institutional structures must be sensitive to physical factors which impose constraints on the exploitation of natural renewable resources (e. G. Variability and uncertainty in the availability of a resource in space, time and quantity, conditions of access, visibility, divisibility,. . ) I develop a typology of diverse ideal-types of SESs according to institutional responses to ecological constraints (especially in terms of appropriate institutional scales or regulation of access to resources). I illustrate this typology by examples of historically sustainable SESs in rural communities of Morocco and Tunisia. These communities are experiencing exogenous and endogenous changes or shocks (population pressure, institutional failures, openess to the market, conflicts between different institutional scales of regulation,. . . ) That are modifying the patterns of the socio-environment interface and can lead to ecological degradations if the necessary institutional adaptations fail to occur.