Book reviews 243

mangroves (Fig. 5.4) to some exquisite drawings of plants (Fig. 6.1), invertebrates (Fig. 8.1) and fish (Fig. 10.2). The graphical figures are also quite variable with a substantial range of fonts and lettering.

Perhaps understandably, given its authorship, there is a substantial North American bias to this book; a section reviewing the major estuaries of the world would have given more balance and made the general reader more aware of the exciting estuaries found in Africa, Australia and elsewhere. The final chapter on human impact in estuaries comes to the same conclusion as so many other books and conferences dealing with ecological problems in recent years, that 'the great problem overall is the continued increase in population and affluence of our own species'.

This is a useful book and one which can be recommended as a student text. However, it should be regarded as more of a book for the intermediate student than the beginner. For the latter there are a number of more suitable introductory volumes, including some very recent ones (e.g. McLusky, D. S. (1990). The Estuarine Ecosystem. Glasgow, Blackie). Both should find a place on the shelves of serious students of estuaries.

Peter S. Maitland

Ecology of Arable Land--Organisms, Carbon and Nitrogen Cycling. Edited by O. Andr6n, T. Lindberg, K. Paustian & T. Rosswall. Ecological Bulletins (Copenhagen), 40, 222 pp. ISBN90-16-10227-4. Price: DKK 300.00.

This book describes a large multidisciplinary project done in Sweden on the ecology of arable land. Within this project the authors attempted to investigate in detail the ecology, and particularly the processes of nitrogen and phosphorus cycling, in an arable field given a range of different management treatments. The book starts off by describing the background to the study, and describes in detail the experimental field which was the object of the study. It then goes on to tackle in detail (1) heat and water processes; (2) the structure of the agroecosystem, including a list of species found during the study, and some of the factors affecting their dynamics; (3) organic carbon and nitrogen flows; (4) inorganic nitrogen cycling processes and flows; and (5) ecosystem dynamics. The book is concluded with an agricultural outlook for Sweden, and what is termed an epilogue, which details the project history and administration. This book is a remarkable hybrid, covering the detailed description of how each of the various sub- studies developed (warts and all), but also producing a very good synopsis of their results. Although the study is based on a single field, the authors do speculate on the relevance of these results to other areas, and their

244 Book reviews

concentration on the development of mathematical models will perhaps allow the validation of their findings elsewhere.

This is not the sort of book that most workers in conservation science will choose to read, because it is essentially a study of arable land. In my view this is a great pity, because there is a great deal of interesting ecology which may have relevance elsewhere, for example the very detailed studies of different groups in the soil fauna. That a large multidisciplinary team has shown what can be done to elucidate the complexities of the ecology of 'a simple ecosystem' (their description) shows how far conservation managers need to go to understand the complexities of natural and semi-natural communities.

R. H. Marrs