Introduction: The Development of Social Ecology Interdisciplinary Research in Society and Nature in the 20th Century Sources of Social Ecology: Discourses on Society and Nature in Sociology Sources of Social Ecology: Ecosystems and Natural Resources in Ecological Discourses Thematic Profiles of Social Ecology: The Research on Resource Flows and the Physical Economy in a Global Context Thematic Profiles of Social Ecology: The Research on Human Land Use, Food and Biomass Production in European and Global Contexts Thematic Profiles of Social Ecology: Knowledge Synthesis in a Theory of Interaction of Society and Nature Social Ecology: A Science in Development Social Ecology and Practice: The Policy Process and the Social-Ecological Discourse.