Social Ecology, one of the richest traditions in modern social sciences and a potential link between the social and the natural sciences, has developed two branches of scholarly work: (1) an environmental social science centred around the concept of the ?ecological complex,? and (2) research on the structure and development of urban areas, urban social ecology. The present book, organized in the respective two parts, gives a state of the art report as it was discussed during the XI World Congress of Sociology, New Delhi, 1986. Twenty authors from ten countries joined in the Research Committee on Social Ecology of the International Sociological Association to present their views on recent theoretical developments and their current research.