The nonagricultural lands of the world are being called upon today to satisfy tremendous demands from society at all levels of economic development. Until recently, costs of management of many of these lands were too high to warrant appreciable management investment for the relatively low yields. Society is beginning to realize, however, that the long-term interests of communities, states and nations are served by careful husbandry of these resources, and efforts are being made throughout the world to improve management practices. Vegetation management on nonagricultural land involves a multitude of species, vast areas, and pitifully small human and dollar resources available for implementation of practices. Herbicides have shown themselves to be economical and versatile at controlling undesirable vegetation, hence an invaluable tool for management. Early herbicide work was necessarily concerned with discovery of specific effectiveness of various compounds on problem species. As sophistication of herbicide techniques improved, it became obvious that application of some materials had substantial ecological impact on flora and fauna, and that this impact could serve or defeat the objectives of the users. The early reports of herbicide action that led to speculation that a panacea for vegetation ills was at hand were accompanied by reports of misuse, failure to accomplish objectives and various undesirable side effects. Experience gained in this early work has shown that herbicidal and ecological considerations must be regarded together for development of intelligent vegetation management programs. Unfortunately, there are few scientists and practitioners who are ecologists, biochemists and soil scientists at the same time. The purpose of this symposium is to offer scientists, practitioners and administrators a comprehensive picture of herbicide science according to the best information available in 1967, and to do so in a form that will lend itself to continued building and teaching. In furtherance of the above objective, many of the world's foremost scientists, and teachers of vegetation science and herbicide technology are represented on this program. Their contributions, together with those of supporting agencies and industry and the individuals that have handled local arrangements are gratefully acknowledged.