J.B. Jones & P.J. Mulholland (2000) Streams and Ground Waters Pp xix + 425. Academic Press, San Diego, USA. ISBN 0-12-389845-5. Price £49.95 (hardback). Since the 1960s, lotic ecologists have begun to expand their spatial perspective on streams because many streams are not isolated from drainage basins and are influenced by the flow of water through underlying sediments (groundwater and/or hyporheic flowpaths). The recognition of the four dimensional character of stream ecosystems has promoted a fast growth in diverse research directions in stream ecology, and the contributors to this book have done an impressive job of reviewing the literature and generating conceptual models that lead to the production of testable hypotheses. The book compiles syntheses of the current state of research on stream surface, subsurface and groundwater interactions. It is organized into three parts: the first covers areas of research on the hydrology, hydraulics and physical structure of streams, the second covers the biogeochemistry of sub-system interactions with the surface water and considers nutrients and metabolism in streams, and the third part covers the biotic surface–subsurface interactions in streams (microorganisms, meiofauna, macrofauna and macrophytes). The book deals with all these subjects in sufficient detail and clarity to bring the readers quickly to a level at which they can understand this complex field. It provides a good overview of current North American research with contrasting examples to earlier European counterparts. Clearly, the diversity of topics included in this book is enriched by the excellent collaboration of hydrologists and ecologists. The first chapter deals with quantifying surface–subsurface hydrological interactions, providing examples of useful field techniques and model calculations to characterize hyporheic zones across stream ecosystems. Theoretical advance in the modelling of surface–subsurface interactions from three perspectives (from that of the stream, the streambed interface and the subsurface) is the subject of Chapter 2. The next nine chapters each focus on a central theme that is of fundamental importance in the understanding of system hydrology. Studying patterns to understand processes and the development of synthetic, broad-scale models in this field are illustrated in Chapters 3 and 4. In Chapter 3, we are given models of stream–riparian interactions which identify times and places where the riparian zone is expected to be an effective nutrient filter. In Chapter 4, this view is reinforced where climate and geomorphology interact to create fundamentally different linkages between the riparian and stream subsystems. The role of groundwater in the understanding of stream ecosystems, such as how ground water inputs affect biogeochemical characteristics of the surface water and the stream biota is summarized in Chapter 5. Empirical evidence that surface and subsurface exchange plays an important role in nutrient dynamics and nutrient spiralling is found in Chapters 6–9. Simulations of stream nutrient models that explicitly incorporate this exchange are the focus of Chapter 6. The habitat-specific focus considers not only how stream biogeochemistry is influenced by groundwater and riparian linkages, but also how these interactions vary across landscapes. Synthesis of specific nutrient dynamics (e.g. forms, pathways, sources, direction control, rate of transformation and redox environment) are given for nitrogen, phosphorus and dissolved organic carbon. A discussion of other elements, in particular sulphur and iron, in the context of anaerobiosis and chemoautotrophy is then provided. The slow scientific progress over the past decades in the study of interstitial population and community dynamics is revealed for subsurface microbial assemblages, meiofauna and macrofauna. Particularly, persistent gaps in the taxonomy of the hyporheic fauna have constrained invertebrate research. Unfortunately, the problem may be more localized to the American side rather than to the European. It is ironic that despite the public's awareness of world-wide declining biodiversity, benthic organisms are threatened by pollution, hydrologic modifications and landscape alterations. Chapter 15, explores the role of lotic macrophytes as they greatly enhance surface–subsurface biogeochemistry and exchange processes by increasing surface–subsurface complexity, decreasing nutrient spiralling through nutrient uptake and through plant–microbial interactions. Chapter 16 identifies points and direction of hydrological exchanges as useful tools to understand biological patterns and process, such as primary production, invertebrate movements and fish behaviour at the streambed surface. The final chapter integrates those preceding it and critically assesses gaps in our knowledge and forecasts future directions for lotic ecology. Here, contributors recognize (i) the necessity of cross-site comparisons, (ii) difficulties of combining and reconciling measurements of detailed subsurface processes and larger scale interpretations, (iii) the need for rigorous testing of conceptual models of longitudinal exchange along a drainage continuum, and (iv) the need for greater research on larger rivers. The book may be targeted for a specialized readership, however, it provides a valuable summary of information on lotic ecology and I recommend it to all limnologists.