90 BOOK REVIEWS

and progress in identifying and measuring the correct parameters has been limited. Thus the empirical nature of the research detailed in this book is striking, but from these empirical studies a pragmatic approach to soil management and conservation has emerged, and it is one which appears on the whole to work. This book does not attempt a considered statement on these pro- blems, but the editors have been successful in giving this potentially unwieldy collection of papers coherence and structure. It would have been interesting to read some of the discussions which presumably took place,

but these are not included. For the geomorphologist there is much raw data and some cause for reflection in the work detailed here. It is timely and useful to bring such studies as these together in a single volume, for they emphasise the universality of the problems faced in this important field of applied earth science.

MICHAEL F. THOMAS Department of Geology

University of St. Andrews

LANDFORMS IN AFRICA, Colin Buckle, London, Long- man. Price: f3.45.

‘Throughout large parts of Africa’, says Buckle in his Preface, ‘most physical geography textbooks and much teaching involved the use of European or North American examples’. For this reason the author has attempted to produce an introduction to geomor- phology for advanced-level geography students in Africa which is based squarely and almost totally on the .study of examples from all over that continent. He has worked hard.

This volume has many positive merits: it is almost cheap, it is splendidly illustrated with clear maps and photos, it is written in a very simple style, it takes apposite examples from all over Africa, its references are tolerably comprehensive and modern; it guides the reader to appropriate map sources for further study, and it covers a wide range of landform types. There is much here that would benefit British and American students brought up on a diet of Malham and the Weald.

Essentially, however, this book is concerned with landforms rather than with geomorphic processes and it is concerned with providing local examples of as many features as possible. Herein lies a possible weakness.

Certain rather important broader topics are absent: there is, for example, no serious discussion of Hortonian and post-Hortonian runoff models. There is no data-based discussion on rates of operation of erosive processes, we gain little impression of what goes on under the rain forest, sea-level and climatic changes are not put in their wider world context, and the role of man (so long continued in Africa) is scarcely alluded to. Students in Africa should perhaps know something about desertization, gully development, the effect of removing a forest cover, and so forth. This book will provide them with little assistance in these respects.

However, sins of omission are the easiest sins for any reviewer to identify, especially in a book of limited length. Used in conjunction with a volume providing some more solid background in certain basic concepts, especially regarding the processes which create land- forms, this book may well d o a great deal to interest and enthuse African students of geomorphology. Advanced-level students tend to like examples and they tend to be inspired by the spectacular. This book will serve them well.

A. GOUDIE University of Oxford

SOIL AND VEGETATION SYSTEMS, Stephen T. Trudgill, Clarendon Press: Oxford University Press, London, 1977. No. of pages: 180. Price: f6.50 (board), f3.00 (paper cover).

In this short book, fewer than 150 pages of text proper, the author attempts to discuss rock, soil and vegetation together as an interactive unit. It had been intended, he states in the Preface, to consider three

systems of flow: nutrients, energy and water. This plan was abandoned in favour of a consideration of nutrients only, and then still further restricted to mineral ele- ments.

Having lost the energy component the discussion must perforce concentrate on mass transfers of materi- als. At the centre of the system put forward is the soil nutrient store. This receives two imputs, from rock weathering and the atmosphere; suffers one output,

BOOK REVIEWS 91

from leaching; and experiences one component of organic cycling, through the vegetation. The chapters on weathering and leaching are quite informative, that on atmospheric input brief, and that on organic cycling perfunctory. It is implies that could we but ascertain the volumes of each of these flows, for every element, together with feedback and other mechanisms which control them, then we should have accounted for the size of the soil store and explained the functioning of the system. Input-output quantities dominate the reasoning; box-and-arrow diagrams, representing stores and flows, abound, and the leaking-bucket analogy for feedback mechanisms is brought in.

The failure to recognize either that organic materials constitute a fourth major and distinctive component of the systems treated, o r that even for the mineral component, vegetation constitutes a store of materials additional to that of soil, is indicative of the inadequate treatment of biological aspects. This might be regarded as a venial fault, for there is value in showing that geo-ecosystems can be approached from the rock wea- thering/soil direction, in contrast to the plant-orien- tated bias inevitable in accounts by ecologists. But a further weakness to the book is the imbalance between

theorizing about models and illustrating them with factual data. Only two solid case studies of flows in systems are given, for calcium and silica in temperate woodland environments. The illustrations of how systems react to change are relevant but far too brief to be of value, 8 pages of examples following 25 of theorizing. Too often when a digested summary of pertinent information is needed we are fobbed off with the card-index holder’s disease, ‘Reference may be made t o . . .’, which the first and second-year under- graduates for whom the book is explicitly intended will find unhelpful.

To seek to analyse geo-ecosystems in an integrated manner was a bold attempt; one suspects even the author himself may realize that it was not successfully achieved. ‘Much of this chapter has been theoretical, if not speculative’ he writes towards the end; the same could be said of the book as a whole.

ANTHONY YOUNG School of Environmental Sciences

University of East Anglia

THE OCEAN-ATMOSPHERE SYSTEM, A. H. Perry and J. important factual information, which in itself will M. Walker, Longman, 1977, No. of pages: 160.

Six chapters are employed to cover an historical look ensure frequent use as a source book.

Considering that they comprise about 70 per cent of the earth’s surface the oceans have had rather a raw deal in the pages of this journal. There are good reasons for this apparent neglect of course, but the regular reader (whom I envisage to be primarily inter- ested in the solid earth) who wishes to discover some of what is going on in our fluid environment would profit from Perry and Walker’s book. It is not an attempt to present comprehensive treatments on both oceanic and atmospheric behaviour. Rather its aim is to consider the ocean and atmosphere as one system and to show how the two main components interact. Parallel with this scientific aim is the educational one of providing a link between the more elementary treatment in J. G. Harvey’s Atmosphere and Ocean: Our Fluid Environ- ments and E. Kraus’s more advanced Atmosphere- Ocean Interaction. As such the book is intended primarily for late undergraduate/early postgraduate consumption by environmental scientists-however they may be labelled.

The volume is not a textbook in the normal sense of the word. It has a pleasing narrative style which intro- duces the reader to new topics through the early classi- cal papers and yet ensures up-to-date knowledge with reference to many recently published articles. Clear, plentiful diagrams are a primary method of presenting

at oceanographic exploration, the major oceanic circu- lations, the action of wind on the sea, ocean-atmos- phere heat exchange, atmospheric responses to the thermal behaviour of the oceans and, finally, a glimpse at international projects and numerical models. Of these, the first three have an oceanographic bias whilst the remaining three are essentially concerned with the comparatively recent work on the effects on atmos- pheric circulation (and thus of course climate) of sea- surface temperature anomalies. Mathematics and physics are used where necessary, particularly in the chapter on wind-driven waves, but the bulk of the book is free of heavy mathematics.

The essentially review style of the book means that those seeking basic instruction in the mechanisms of atmosphere and ocean must look elsewhere. Neverthe- less the authors are to be congratulated for their compilation and lucid presentation of a wide range of material. Students in the author’s chosen market place will have every cause to thank them for their efforts.

B. ATKINSON Queen Mary College University of London