With graduate degrees in Botany and Ecology from the University of California, Santa Barbara, Stephen (Steve) R. Gliessman has accumulated more than 50 years of teaching, research, and production experience in the field of agroecology. His international experiences in tropical and temperate agriculture, small-farm and large-farm systems, traditional and conventional farm management, hands-on and academic activities, non-profit and business employment, and organic farming have provided a unique combination of experiences and perspectives to incorporate into this book. He was the founding director of the University of California, Santa Cruz, Agroecology Program, one of the first formal agroecology programs in the world, and was the Alfred and Ruth Heller Professor of Agroecology in the Department of Environmental Studies at UCSC until his retirement in 2012. He is the co-founder of the non-profit Community Agroecology Network (CAN) and currently serves on its board of directors. He is the editor of the international journal Agroecology and Sustainable Food Systems and dry farms organic wine grapes and olives with his wife Robbie in northern Santa Barbara County, California.V. Ernesto Méndez is Professor of Agroecology and Environmental Studies at the University of Vermont’s (UVM) Environmental Program and Department of Plant and Soil Science, where he also co-directs the Agroecology and Livelihoods Collaborative (ALC) with Martha Caswell. With degrees in Crop Science, Tropical Agroforestry, and Agroecology, he focuses his research and teaching on agroecology, agri-food systems, participatory action research (PAR), coffee agroecology, transdisciplinary research approaches, and social justice. At UVM he is also a faculty member of the Food Systems Graduate Program, fellow and steering committee member of the Gund Institute for Environment. He has more than 25 years of experience working with smallholder farmers and Indigenous communities in Latin America and collaborating in agroecology efforts across the world. He has authored or co-authored more than 60 peer-reviewed articles and chapters and edited three books. Ernesto was born and raised in El Salvador and maintains deep connections, in life and work, with his Central American roots.Victor M. Izzo is an agricultural entomologist and Lecturer of Agroecology and Environmental Studies in the Plant and Soil Science Department and Environmental Program at the University of Vermont. He also serves as the Education Coordinator of the Agroecology and Livelihoods Collaborative (ALC) and is the co-founder of the Vermont Entomology and Participatory Action Research Team (VEPART), also housed within the Department of Plant and Soil Science. With degrees in Chemistry, Bioscience, and Plant and Soil Science, Vic brings a broad perspective to his work as an agroecologist and teacher. Whether it is a high school classroom in Mexico City, a Master Gardener workshop on a New England farm, or an agroecology course on a university campus, he is always looking to create innovative learning communities built on trust, empathy, and the co-production of knowledge. When he is not in a classroom or on a farm, Vic is with his partner Carolina and son Nico tending to their many gardens and indulging in their respective culinary traditions of Italy and Mexico. Eric W. Engles is a freelance editor, independent scholar, photographer, and naturalist. With experience in the natural sciences, a graduate degree in Sociology, and recognized achievement in the arts, he has developmentally edited more than two dozen books published by academic presses in fields ranging from environment and history to art and behavioral sciences. He has always tended a home garden, and the current two-decade gardening endeavor, in the foothills of the Sierra Nevada, supplies him and his wife Lisa with much of their food.

"Agroecology: Leading the Transformation to a Just and Sustainable Food System has been and remains the go-to textbook on the subject. Each edition has encompassed new topics and remained intellectually fresh, reflecting the truly dynamic nature of the field. The current edition is no exception. In the spirit of "passing the torch," this new edition includes the insights of two coauthors, Ernesto Méndez and Victor Izzo, both of whom are located within the intellectually vibrant and evolving discipline of agroecology. Together, the authors represent three generations of agroecological researchers. It seems to be true that every new intellectual discipline requires a foundational textbook. Agroecology is that work. In this fourth edition it offers the best and most comprehensive foundation so far."John Vandermeer and Ivette Perfecto, Ann Arbor, Michigan, USA, October 2021"In this critical moment in history, there is an ever-growing need to advance a broader understanding of food systems, and of the opportunities to transition to ones that are both more just and more sustainable. This textbook is a pivotal piece of meeting that need, offering an invaluable overview of the science, practice, and movement of agroecology that is both comprehensive and accessible to all those who wish to work toward something better."Marcia DeLonge, Senior Scientist, Union of Concerned Scientists, USA, April 2022"This book is the most comprehensive and rigorous compendium of everything you need to know if you are approaching the world of Agroecology and want to transform the unsustainable food regime. It highlights the effort to extend the principles of Agroecology to the analysis of the food system as a whole, an update that includes all dimensions of agroecological thought and action, including politics. The reader will find in this complete textbook everything needed for a complete understanding of Agroecology: it is a necessary reading."Manuel González de Molina, Agroecosystem History Laboratory, Universidad Pablo de Olavide, Spain, May 2022"An outstanding and comprehensive textbook on agroecology and its various dimensions and elements. This updated and expanded fourth edition includes new highly relevant chapters such as agroecology and climate change as well as new insights about the agroecology and food systems transformation, making it extremely valuable and recommendable for a broad range of readers."Alexander Wezel, Head of Research, Professor for Agroecology and Landscape Ecology, ISARA, France, May 2022"Stephen Gliessman has again shown his visionary leadership in this 4th edition of the text Agroecology! Three earlier editions have been appreciated by Ecological Agriculture students for their scientific grounding in ecology, clear writing and illustration of concepts, and thoughtful end-of-chapter questions. The newest edition, with three additional collaborators, expands social, economic and political perspectives currently under discussion in this dynamic field. As food system failings become more apparent and climate chaos more acute, future students of agroecology will find in this textbook critical background for making agricultural and food system change." Martha Rosemeyer, The Evergreen State College, faculty emeritus, USA, August 2022

• ForewordPreface 1Preface 2AuthorsRecommendations for Using this TextbookSection I • Pathway to Agroecology1 The Case for Fundamental Change in Agriculture2 Alternatives to Industrial Agriculture3 The Agroecosystem ConceptSection II • Agricultural Organisms and their Environment4 The Plant: Nutrition, Growth, and Response to the Environment5 Light6 Climatic Factors Affecting Plants7 Biotic Factors and Interactions among Organisms8 The Soil Ecosystem9 The Environmental ComplexSection III • System-Level Interactions10 Population Ecology of Agroecosystems11 Genetic Resources in Agroecosystems12 Species Interactions in Crop Communities13 Agroecosystem Diversity14 Ecological Pest, Weed, and Disease Management15 Successional Development and Agroforestry16 Animals in Agroecosystems 17 Energetics of Agroecosystems18 Landscape DiversitySection IV • Agroecological Farms and Communities19 Sustainability and Its Assessment20 Converting Farms to Ecologically Based Management21 Bringing Farmers and Consumers Closer Together22 Urban and Peri-urban AgricultureSection V • Transforming the Global Food System23 Achieving a Just and Sustainable Food System24 Economic Dynamics of the Food System25 Agriculture and the Climate Crisis26 Shaping the Future in the PresentGlossaryReferencesIndex

With graduate degrees in Botany and Ecology from the University of California, Santa Barbara, Stephen (Steve) R. Gliessman has accumulated more than 50 years of teaching, research, and production experience in the field of agroecology. His international experiences in tropical and temperate agriculture, small-farm and large-farm systems, traditional and conventional farm management, hands-on and academic activities, non-profit and business employment, and organic farming have provided a unique combination of experiences and perspectives to incorporate into this book. He was the founding director of the University of California, Santa Cruz, Agroecology Program, one of the first formal agroecology programs in the world, and was the Alfred and Ruth Heller Professor of Agroecology in the Department of Environmental Studies at UCSC until his retirement in 2012. He is the co-founder of the non-profit Community Agroecology Network (CAN) and currently serves on its board of directors. He is the editor of the international journal Agroecology and Sustainable Food Systems and dry farms organic wine grapes and olives with his wife Robbie in northern Santa Barbara County, California.V. Ernesto Méndez is Professor of Agroecology and Environmental Studies at the University of Vermont’s (UVM) Environmental Program and Department of Plant and Soil Science, where he also co-directs the Agroecology and Livelihoods Collaborative (ALC) with Martha Caswell. With degrees in Crop Science, Tropical Agroforestry, and Agroecology, he focuses his research and teaching on agroecology, agri-food systems, participatory action research (PAR), coffee agroecology, transdisciplinary research approaches, and social justice. At UVM he is also a faculty member of the Food Systems Graduate Program, fellow and steering committee member of the Gund Institute for Environment. He has more than 25 years of experience working with smallholder farmers and Indigenous communities in Latin America and collaborating in agroecology efforts across the world. He has authored or co-authored more than 60 peer-reviewed articles and chapters and edited three books. Ernesto was born and raised in El Salvador and maintains deep connections, in life and work, with his Central American roots.Victor M. Izzo is an agricultural entomologist and Lecturer of Agroecology and Environmental Studies in the Plant and Soil Science Department and Environmental Program at the University of Vermont. He also serves as the Education Coordinator of the Agroecology and Livelihoods Collaborative (ALC) and is the co-founder of the Vermont Entomology and Participatory Action Research Team (VEPART), also housed within the Department of Plant and Soil Science. With degrees in Chemistry, Bioscience, and Plant and Soil Science, Vic brings a broad perspective to his work as an agroecologist and teacher. Whether it is a high school classroom in Mexico City, a Master Gardener workshop on a New England farm, or an agroecology course on a university campus, he is always looking to create innovative learning communities built on trust, empathy, and the co-production of knowledge. When he is not in a classroom or on a farm, Vic is with his partner Carolina and son Nico tending to their many gardens and indulging in their respective culinary traditions of Italy and Mexico. Eric W. Engles is a freelance editor, independent scholar, photographer, and naturalist. With experience in the natural sciences, a graduate degree in Sociology, and recognized achievement in the arts, he has developmentally edited more than two dozen books published by academic presses in fields ranging from environment and history to art and behavioral sciences. He has always tended a home garden, and the current two-decade gardening endeavor, in the foothills of the Sierra Nevada, supplies him and his wife Lisa with much of their food.

"Agroecology: Leading the Transformation to a Just and Sustainable Food System has been and remains the go-to textbook on the subject. Each edition has encompassed new topics and remained intellectually fresh, reflecting the truly dynamic nature of the field. The current edition is no exception. In the spirit of "passing the torch," this new edition includes the insights of two coauthors, Ernesto Méndez and Victor Izzo, both of whom are located within the intellectually vibrant and evolving discipline of agroecology. Together, the authors represent three generations of agroecological researchers. It seems to be true that every new intellectual discipline requires a foundational textbook. Agroecology is that work. In this fourth edition it offers the best and most comprehensive foundation so far."John Vandermeer and Ivette Perfecto, Ann Arbor, Michigan, USA, October 2021"In this critical moment in history, there is an ever-growing need to advance a broader understanding of food systems, and of the opportunities to transition to ones that are both more just and more sustainable. This textbook is a pivotal piece of meeting that need, offering an invaluable overview of the science, practice, and movement of agroecology that is both comprehensive and accessible to all those who wish to work toward something better."Marcia DeLonge, Senior Scientist, Union of Concerned Scientists, USA, April 2022"This book is the most comprehensive and rigorous compendium of everything you need to know if you are approaching the world of Agroecology and want to transform the unsustainable food regime. It highlights the effort to extend the principles of Agroecology to the analysis of the food system as a whole, an update that includes all dimensions of agroecological thought and action, including politics. The reader will find in this complete textbook everything needed for a complete understanding of Agroecology: it is a necessary reading."Manuel González de Molina, Agroecosystem History Laboratory, Universidad Pablo de Olavide, Spain, May 2022"An outstanding and comprehensive textbook on agroecology and its various dimensions and elements. This updated and expanded fourth edition includes new highly relevant chapters such as agroecology and climate change as well as new insights about the agroecology and food systems transformation, making it extremely valuable and recommendable for a broad range of readers."Alexander Wezel, Head of Research, Professor for Agroecology and Landscape Ecology, ISARA, France, May 2022"Stephen Gliessman has again shown his visionary leadership in this 4th edition of the text Agroecology! Three earlier editions have been appreciated by Ecological Agriculture students for their scientific grounding in ecology, clear writing and illustration of concepts, and thoughtful end-of-chapter questions. The newest edition, with three additional collaborators, expands social, economic and political perspectives currently under discussion in this dynamic field. As food system failings become more apparent and climate chaos more acute, future students of agroecology will find in this textbook critical background for making agricultural and food system change." Martha Rosemeyer, The Evergreen State College, faculty emeritus, USA, August 2022

• ForewordPreface 1Preface 2AuthorsRecommendations for Using this TextbookSection I • Pathway to Agroecology1 The Case for Fundamental Change in Agriculture2 Alternatives to Industrial Agriculture3 The Agroecosystem ConceptSection II • Agricultural Organisms and their Environment4 The Plant: Nutrition, Growth, and Response to the Environment5 Light6 Climatic Factors Affecting Plants7 Biotic Factors and Interactions among Organisms8 The Soil Ecosystem9 The Environmental ComplexSection III • System-Level Interactions10 Population Ecology of Agroecosystems11 Genetic Resources in Agroecosystems12 Species Interactions in Crop Communities13 Agroecosystem Diversity14 Ecological Pest, Weed, and Disease Management15 Successional Development and Agroforestry16 Animals in Agroecosystems 17 Energetics of Agroecosystems18 Landscape DiversitySection IV • Agroecological Farms and Communities19 Sustainability and Its Assessment20 Converting Farms to Ecologically Based Management21 Bringing Farmers and Consumers Closer Together22 Urban and Peri-urban AgricultureSection V • Transforming the Global Food System23 Achieving a Just and Sustainable Food System24 Economic Dynamics of the Food System25 Agriculture and the Climate Crisis26 Shaping the Future in the PresentGlossaryReferencesIndex

With graduate degrees in Botany and Ecology from the University of California, Santa Barbara, Stephen (Steve) R. Gliessman has accumulated more than 50 years of teaching, research, and production experience in the field of agroecology. His international experiences in tropical and temperate agriculture, small-farm and large-farm systems, traditional and conventional farm management, hands-on and academic activities, non-profit and business employment, and organic farming have provided a unique combination of experiences and perspectives to incorporate into this book. He was the founding director of the University of California, Santa Cruz, Agroecology Program, one of the first formal agroecology programs in the world, and was the Alfred and Ruth Heller Professor of Agroecology in the Department of Environmental Studies at UCSC until his retirement in 2012. He is the co-founder of the non-profit Community Agroecology Network (CAN) and currently serves on its board of directors. He is the editor of the international journal Agroecology and Sustainable Food Systems and dry farms organic wine grapes and olives with his wife Robbie in northern Santa Barbara County, California.V. Ernesto Méndez is Professor of Agroecology and Environmental Studies at the University of Vermont’s (UVM) Environmental Program and Department of Plant and Soil Science, where he also co-directs the Agroecology and Livelihoods Collaborative (ALC) with Martha Caswell. With degrees in Crop Science, Tropical Agroforestry, and Agroecology, he focuses his research and teaching on agroecology, agri-food systems, participatory action research (PAR), coffee agroecology, transdisciplinary research approaches, and social justice. At UVM he is also a faculty member of the Food Systems Graduate Program, fellow and steering committee member of the Gund Institute for Environment. He has more than 25 years of experience working with smallholder farmers and Indigenous communities in Latin America and collaborating in agroecology efforts across the world. He has authored or co-authored more than 60 peer-reviewed articles and chapters and edited three books. Ernesto was born and raised in El Salvador and maintains deep connections, in life and work, with his Central American roots.Victor M. Izzo is an agricultural entomologist and Lecturer of Agroecology and Environmental Studies in the Plant and Soil Science Department and Environmental Program at the University of Vermont. He also serves as the Education Coordinator of the Agroecology and Livelihoods Collaborative (ALC) and is the co-founder of the Vermont Entomology and Participatory Action Research Team (VEPART), also housed within the Department of Plant and Soil Science. With degrees in Chemistry, Bioscience, and Plant and Soil Science, Vic brings a broad perspective to his work as an agroecologist and teacher. Whether it is a high school classroom in Mexico City, a Master Gardener workshop on a New England farm, or an agroecology course on a university campus, he is always looking to create innovative learning communities built on trust, empathy, and the co-production of knowledge. When he is not in a classroom or on a farm, Vic is with his partner Carolina and son Nico tending to their many gardens and indulging in their respective culinary traditions of Italy and Mexico. Eric W. Engles is a freelance editor, independent scholar, photographer, and naturalist. With experience in the natural sciences, a graduate degree in Sociology, and recognized achievement in the arts, he has developmentally edited more than two dozen books published by academic presses in fields ranging from environment and history to art and behavioral sciences. He has always tended a home garden, and the current two-decade gardening endeavor, in the foothills of the Sierra Nevada, supplies him and his wife Lisa with much of their food.

"Agroecology: Leading the Transformation to a Just and Sustainable Food System has been and remains the go-to textbook on the subject. Each edition has encompassed new topics and remained intellectually fresh, reflecting the truly dynamic nature of the field. The current edition is no exception. In the spirit of "passing the torch," this new edition includes the insights of two coauthors, Ernesto Méndez and Victor Izzo, both of whom are located within the intellectually vibrant and evolving discipline of agroecology. Together, the authors represent three generations of agroecological researchers. It seems to be true that every new intellectual discipline requires a foundational textbook. Agroecology is that work. In this fourth edition it offers the best and most comprehensive foundation so far."John Vandermeer and Ivette Perfecto, Ann Arbor, Michigan, USA, October 2021"In this critical moment in history, there is an ever-growing need to advance a broader understanding of food systems, and of the opportunities to transition to ones that are both more just and more sustainable. This textbook is a pivotal piece of meeting that need, offering an invaluable overview of the science, practice, and movement of agroecology that is both comprehensive and accessible to all those who wish to work toward something better."Marcia DeLonge, Senior Scientist, Union of Concerned Scientists, USA, April 2022"This book is the most comprehensive and rigorous compendium of everything you need to know if you are approaching the world of Agroecology and want to transform the unsustainable food regime. It highlights the effort to extend the principles of Agroecology to the analysis of the food system as a whole, an update that includes all dimensions of agroecological thought and action, including politics. The reader will find in this complete textbook everything needed for a complete understanding of Agroecology: it is a necessary reading."Manuel González de Molina, Agroecosystem History Laboratory, Universidad Pablo de Olavide, Spain, May 2022"An outstanding and comprehensive textbook on agroecology and its various dimensions and elements. This updated and expanded fourth edition includes new highly relevant chapters such as agroecology and climate change as well as new insights about the agroecology and food systems transformation, making it extremely valuable and recommendable for a broad range of readers."Alexander Wezel, Head of Research, Professor for Agroecology and Landscape Ecology, ISARA, France, May 2022"Stephen Gliessman has again shown his visionary leadership in this 4th edition of the text Agroecology! Three earlier editions have been appreciated by Ecological Agriculture students for their scientific grounding in ecology, clear writing and illustration of concepts, and thoughtful end-of-chapter questions. The newest edition, with three additional collaborators, expands social, economic and political perspectives currently under discussion in this dynamic field. As food system failings become more apparent and climate chaos more acute, future students of agroecology will find in this textbook critical background for making agricultural and food system change." Martha Rosemeyer, The Evergreen State College, faculty emeritus, USA, August 2022

• ForewordPreface 1Preface 2AuthorsRecommendations for Using this TextbookSection I • Pathway to Agroecology1 The Case for Fundamental Change in Agriculture2 Alternatives to Industrial Agriculture3 The Agroecosystem ConceptSection II • Agricultural Organisms and their Environment4 The Plant: Nutrition, Growth, and Response to the Environment5 Light6 Climatic Factors Affecting Plants7 Biotic Factors and Interactions among Organisms8 The Soil Ecosystem9 The Environmental ComplexSection III • System-Level Interactions10 Population Ecology of Agroecosystems11 Genetic Resources in Agroecosystems12 Species Interactions in Crop Communities13 Agroecosystem Diversity14 Ecological Pest, Weed, and Disease Management15 Successional Development and Agroforestry16 Animals in Agroecosystems 17 Energetics of Agroecosystems18 Landscape DiversitySection IV • Agroecological Farms and Communities19 Sustainability and Its Assessment20 Converting Farms to Ecologically Based Management21 Bringing Farmers and Consumers Closer Together22 Urban and Peri-urban AgricultureSection V • Transforming the Global Food System23 Achieving a Just and Sustainable Food System24 Economic Dynamics of the Food System25 Agriculture and the Climate Crisis26 Shaping the Future in the PresentGlossaryReferencesIndex