Introduction: Agroecology as a Transdisciplinary, Participatory, and Action-oriented Approach V. Ernesto Mendez, Christopher M. Bacon, and Roseann Cohen Agroecology: Roots of Resistance to Industrialized Food Systems Stephen R. Gliessman Transformative Agroecology: Foundations in Agricultural Practice, Agrarian Social Thought, and Sociological Theory Graham Woodgate and Eduardo Sevilla Guzman Political Agroecology: An Essential Tool to Promote Agrarian Sustainability Manuel Gonzalez de Molina Learning Agroecology through Involvement and Reflection Charles Francis, Edvin Ostergaard, Anna Marie Nicolaysen, Geir Lieblein, Tor Arvid Breland, and Suzanne Morse Complexity in Tradition and Science: Intersecting Theoretical Frameworks in Agroecological Research John Vandermeer and Ivette Perfecto Agroecology, Food Sovereignty, and the New Green Revolution Eric Holt-Gimenez and Miguel A. Altieri The Intercultural Origin of Agroecology: Contributions from Mexico Francisco J. Rosado-May Participatory Action Research for an Agroecological Transition in Spain: Building Local Organic Food Networks Gloria I. Guzman, Daniel Lopez, Lara Roman, and Antonio M. Alonso Agroecology, Food Sovereignty, and Urban Agriculture in the United States Margarita Fernandez, V. Ernesto Mendez, Teresa Mares, and Rachel Schattman On the Ground: Putting Agroecology to Work through Applied Research and Extension in Vermont Debra Heleba, Vern Grubinger, and Heather Darby Agroecology as a Food Security and Sovereignty Strategy in Coffee-Growing Communities: Opportunities and Challenges in San Ramon, Nicaragua Heather Putnam, Roseann Cohen, and Roberta M. Jaffe The Mesoamerican Agroenvironmental Program: Critical Lessons Learned from an Integrated Approach to Achieve Sustainable Land Management Isabel A. Gutierrez-Montes and Felicia Ramirez Aguero Analysis of Tropical Home Gardens through an Agroecology and Anthropological Ecology Perspective Alba Gonzalez-Jacome