This book, a product of the fourth Cary Conference, amply demonstrates the achievement of a major goal of all Cary Conferences. That is, Cary Conferences were conceived to provide a forum for comprehensive discus sion of major ecological issues from more philosophical and comprehensive perspectives. The Institute of Ecosystem Studies is proud to make its staff and facilities available on a biennial basis for the purpose of initiating and fostering these important discussions. On the one hand, the influence of humans on ecosystems may be quite obvious, such as when a forest is cut. On the...