This book results from a summer school held at Cornell University in 1992. The participants were graduate students and postdoctoral researchers selected from a broad range of interests and backgrounds in ecological studies. The summer school was the second in a continuing series whose underlying aim and the aim of this volume-is to bring together the different methods and concepts underpinning terrestrial, freshwater, and marine ecology. The first volume in the series focused on patch dynamics in these three ecologi cal sectors. Here we have endeavored to complement that volume by extending its comparative approach to the consideration of ecological time series. The types of data and the methods of collection are necessarily very different in these contrasting environments, yet the underlying concept and the technical problems of analysis have much in common. It proved to be of great interest and value to the summer school participants to see the differences and then work through to an appreciation ofthe generalizable concepts. We believe that such an approach must have value as well for a much larger audience, and we have structured this volume to provide a comparable reading experience.