Management of the renewable natural resources in Madagascar is gradually being transferred to the local communities, particularly that of forest resources. However, these local communities are struggling to assess the consequences of management plans that they themselves must develop and implement on ecologically, economically and socially sustainable grounds. In order to highlight key aspects of different management options beforehand, we have developed MIRANA, a computer model to simulate various scenarios of management plan implementation. MIRANA differs from other simulation models by not only taking into account individual practices and economic exchanges, but also by accounting for the applicable regulations. These regulations are taken into consideration by means of a multiplicity of normative structures within a spatial context. The objective of this paper is to describe the representations of institutions, norms and territories proposed by MIRANA and to discuss these representations in relation to the state of the art in the field of normative multi-agent systems.