This is the first volume devoted to the integration of population and ecosystem ecology--an approach that offers vast potential for improving our understanding of the complexities of nature and the management of environmental problems. The editors, Clive Jones and John Lawton, work at the Institute of Ecosystem Studies in New York and the Natural Environment Research Council Centre for Population Biology in England, respectively. They have brought together a distinguished group of experts to explore diverse aspects of linking species and ecosystem perspectives: theoretical, empirical and pragmatic including: *processes that range from a local to a planetary scale *the role of organisms as ecosystem engineers *the use of ecological flow chains to link population and ecosystem processes *numerous examples of the influence of species on ecosystem processes and vice versa *a unique blend of problems and processes drawn from marine, freshwater and terrestrial ecosystems *problems of species redundancy in ecosystem processes *stoichiometric constraints on species interactions; *scaling and aggregation problems. The book establishes conceptual frameworks for the rigorous study of interactions between species and ecosystems, it points to still-unanswered questions, and it identifies future research directions. Integration of ecology with its implications for teaching, research and society are central to the book. This pioneering volume will be an indispensable resource for ecology researchers, students, and environmental managers and will stimulate debate on the future integration of the field.