Structural and functional analysis of the transformation of the agrarian landscape in the catalan Vallès county during the last 150 years (1853-2004): Its raltionship with a sustainable use of the territory

Abstract

This research intends to verify the hypothesis that a serious reduction of the territorial efficiency, which is related to a significant landscape transformation, underlies the observed loss of energy efficiency that the agrarian systems experienced during the last 150 years. To do so, a structural and functional analysis of the changes experienced by the agrarian landscape in one portion of the Vallès county (Barcelona Metropolitan Area) has been made through an innovative methodology that combines two indicators from the landscape ecology (cover diversity and ecological fragmentation), with two new socioenvironmental indexes recently developed by some of the authors (eco-landscape structure and ecological connectivity). The results show an increase in cover diversity, ecological fragmentation and anthropogenic barriers, as well as a growth in landscape diversity which are associated to a substantial reduction of the ecologically functional areas, and its ecological connectivity. These transformations resulted on a severe loss of landscape functionality and territorial efficiency in the study area. All these changes happened at the same time as a sharp reduction in the energy agricultural returns to energy inputs, suggesting the need for a deeper trans-disciplinary dialogue between natural and social sciences, in a common historical background, to develop new criteria and methods in order to undertake a more sustainable type of land use planning.