This article traces multiple directions in the evolution of agroecology, from its early emphasis on ecological processes in agricultural systems, to its emergence as a multidimensional approach focusing on broader agro-food systems. This review is timely, as agroecology is being increasingly applied within a diversity of scientific-, policy-, and farmer-based initiatives. We contrast different agroecological perspectives or agroecologies€ and discuss the characteristics of an agroecology characterized by a transdisciplinary, participatory and action-oriented approach. Our final discussion describes the contents of the special issue, and states our goal for this compilation, which is to encourage future work that embraces an agroecological approach grounded in transdisciplinarity, participation, and transformative action. Hence, the specific objectives of this introductory article and of this inaugural issue of Agroecology and Sustainable Food Systems were to1) discuss the implications of the increasing use and adoption of agroecology in unprecedented scientific, social and political spaces; 2) examine the evolution of the field of agroecology into distinct perspectives, or agroecologies; and 3) present conceptual and applied contributions of an agroecological perspective grounded in transdisciplinary, participatory, and action-oriented approaches. We finalize this article with a description of how the other contributions to the special issue complement each other to form a coherent and integrated agroecological approach.
