Preface / F. Fournier and A. Szollosi-Nagy -- 1. The groundwater/surface water perspective: state of the art / J. Gibert, F. Fournier and J. Mathieu -- 2. Ecotonal animal assemblages; their interest for groundwater studies / D.L. Danielopol, R. Rouch and P. Pospisil ... [et al.] -- 3. Stochasticity in resource utilization by a larval chironomidae (diptera) community in the bed sediments of a gravel stream / P.E. Schmid -- 4. Temporal and spatial dynamics of meiofaunal assemblages in the hyporheic interstitial of a gravel stream / J.M. Schmid-Araya -- 5. Interstitial fauna along an epigean-hypogean gradient in a Rocky Mountain river / J.V. Ward and N.J. Voelz -- 6. Filter effect of karstic spring ecotones on the population structure of the hypogean amphipod Niphargus virei / F. Malard, M.J. Turquin and G. Magniez -- 7. Community respiration in the hyporheic zone of a riffle-pool sequence / M. Pusch. Ecotones are zones where ecological processes are more intense and resources more diversified. They are also zones which react quickly to human influences and changes of environmental variables. This volume is derived from an international conference of the Ecotone project, established under the dual responsibility of the UNESCO International Hydrological Programme and the Man and Biosphere Programme, and summarizes the results of the subnetwork activities devoted to the study of groundwater/surface water interactions. The contributors were carefully selected on their international scientific reputation to represent the multidisciplinary viewpoints of hydrologists, biologists and ecologists. Topics covered include interrelationships between surface water and groundwater in riparian forests, wetlands, areas surrounding lakes and alluvial flood plains. This book defines strategies for the integration of data obtained by different disciplines in order to provide a scientific basis for the sound ecological management of water resources leading to sustainable development of the environment. It addresses areas of active research in hydrology and biology, and is therefore aimed towards researchers, water resource project managers, and policy makers.