This paper encompasses the historiography of ideas about geographical space and the relationship to research methods, sources and selection of topics of study. Attention is focused on environmental resources and their activation systems. In the first part of the paper the problem is posed in general terms, accord¬ing to different perspectives (geography, historical ecology and social history). The second part explains the convergent routes which led to identify common problems: the experience of the "new local history" and the "geographical historical microanalysis". The last part focuses on the identification of a specific multiple land-use system at work in the Imperial Fiefs of the Doria Pamphilj family, in the Ge¬noese Apennines (18th century). The result shows that comparing and combin¬ing the analytical approach to themes of political history and to the ecology of the site is functional to a "realistic" deciphering of the local historical dynamics which affected and qualified the environmental resources.