Pace 9617026 In 1985 the Institute of Ecosystem Studies inaugurated a series of "Cary Conferences" with sponsorship by the Mary Flagler Cary Charitable Trust. These conferences which have all focused on discussion and examination of fundamental issues in ecology have been attended by over 350 scientists from 20 countries. This award will assist in the support of the seventh Cary Conference to be held in May 1997, which will focus on ecosystem science by identifying and characterizing past successes, evaluating limitations and exploring frontiers. Successes are defined as bodies of work that have 1) advanced our scientific understanding of ecosystem structure and function, and 2) provided insight and solutions to environmental problems. The conference will focus on current conceptual limitations and how these might be resolved. Limitations will also be critically addressed from the perspective of how ecosystem science can develop its scope for prediction and application. The frontiers of ecosystem science will be explored by examining important conceptual areas and the potential for the application of new approaches to standing problems. A major thesis behind this analysis is that ecosystem science is unique in that many of the major advances in the field have been driven by the emergence of new environmental problems that could not be solved with existing approaches and techniques. Explicit recognition of the relationships between environmental problems and progress in ecosystem ecology may be very useful for determining the key factors that have led to successes in this field, highlighting what limits progress, and improving ability to predict and address frontier topics. A conference volume will provide an evaluation of the state of ecosystem research and should be of wide interest to practitioners, new students entering, the field, and other ecologists curious about contemporary ecosystem research. A more general interest brochure and/or electronic media and web page will demonstrate t he strength and values of ecosystem ecology to a broader audience, including scientists from other disciplines, environmental managers, and scientific funding agency personnel.