Una interpretación de los cambios de uso del suelo desde el punto de vista del metabolismo social agrario. La comarca catalana del Vallès, 1853-2004

A landscape can be seen as the territorial expression of the metabolism that any society maintains with natural systems. A way to understand how and why human intervention change the shape of territory is to analyze the energy flows driven by the economy that interact with the environment leaving an ecological imprint on it. This research seeks to test, by means of the energy flow analysis and the diachronic use of landscape ecology indexes, the hypothesis that a serious reduction of the territorial efficiency, which is related to a significant landscape degradation, underlies the observed increase in external inputs and the corresponding loss of energy efficiency that the agrarian systems experienced after the “green revolution”, together with the abandonment and degradation of the traditional Mediterranean land mosaics. The results obtained in five municipalities of the Catalan Vallès county verify the close link that existed throughout the last 150 years between energy efficiency, territorial efficiency and the ecological state of landscape.