The transformation of provisioning systems from an integrated perspective of social metabolism and political economy : a conceptual framework - Schaffartzik, Anke (Universitat Autònoma de Barcelona. Institut de Ciència i Tecnologia Ambientals) ; Pichler, Melanie (University of Natural Resources and Life Sciences. Institute of Social Ecology) ; Pineault, Eric (Université du Québec à Montréal. Institut des Sciences de l'Environnement) ; Wiedenhofer, Dominik (University of Natural Resources and Life Sciences. Institute of Social Ecology) ; Gross, Robert (University of Innsbruck. Institute of History and European Ethnology) ; Haberl, Helmut (University of Natural Resources and Life Sciences. Institute of Social Ecology)