Can desert encroachment be stopped? A study with emphasis on Africa

434 partly internal, deriving out of a re-appraisal of the subject's approaches and manners of presentation and, in part, the downstream consequence of advances in meteorology itself. Climatology, or at least, the best climatology, has its feet fairly firmly planted on the physical and dynamic foundations of modern meteorology, and uses much the same language. Gone~ one hopes, are the endless tables of average weather, often rather dull, dominantly descriptive and rarely very useful. Modern climatology aims to establish the physical explanations as a basis for sound understanding and description, and purposeful application. This volume exemplifies all these admirable qualities. In parallel with those in several other countries, a comprehensive review of the climate of Japan, typical of its time, was published in the 1930s. In the subsequent 46 years, enormous quantities of new information and highly significant advances of insight have been made into the country's weather. The present is therefore an appropriate time to use this vast amount of knowledge to produce a new text on The Climate of Japan. Written b y eight leading Japanese climatologists, the contributions have been neatly integrated and interrelated by the editor. The topics covered include the broad geographical setting; the annual cycle of seasons; the dynamic and synoptic controls; the winter monsoon; the early summer rainy season and other singularities; typhoons; the heat and water balance; circulation systems; air pollution; urban climates; climatic divisions of the country, and changes in climate. No two climatologists would agree on the most logical sequence for regional climatic description and analysis. The reviewer would have preferred the general dynamic and synoptic scene to be set before some of its consequences. This might have made a more logical sequence. But, in spite of this qualification, one can only admire the success which has followed the enormous tasks of analysis and presentation which this volume represents. In it one will find not only the expected information of basic climatology, but also of less c o m m o n parameters such as ground temperatures, river discharges, evaporation from lakes and seas, and air pollution. For anyone seeking the latest information on, and explanations of, the climate of Japan, this is by far the best source available in English. The text is easy to read, the diagrams are numerous and clearly drawn, and the whole b o o k is attractively published. It is a model which other climatologists, contemplating similar studies in other countries, might well emulate; provided, that is, they have the benefit of an enormous data source such as the one upon which this study is based. TONY J. CHANDLER (Manchester) Can Desert Encroachment be Stopped? A Study with Emphasis on Africa. A. Rapp, H. N. Le Houerou and B. Lundholm (Editors). Ecological Bulletin No. 24, Swedish Natural Science Research Council, Box 23136 S--104 35 t, Stockholm, 1977, 240 pp.

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This bulletin has been prepared as a background paper for the 1977 U.N. Conference on Desertization, and is published in co-operation with the U.N. Environmental Programme and the Swedish Secretariat for International Ecology. There are ten contributors, five from Sweden and five who are actively working in the arid and semi-arid regions of Africa. The bulletin is primarily concerned with the problems of land use in the areas bordering the Sahara, but there are short discussions on some related problems in Iran, Syria and Botswana. It is recognised that the fundamental problem is the main. tenance of a viable pastoral and probably semi-nomadic e c o n o m y in areas of marginal and erratic rainfall, when both the pastoral populations and their flocks and herds are increasing and agricultural development is taking place in the more reliable rainfall areas on their more humid fringes. There are 13 chapters in the book, many of which are taken up with tables, maps and diagrams, and one chapter is in seven sections, each a short study of the problems of a selected region, so that the treatment must be largely in general terms with little discussion in depth of the various topics treated. But at the end of each chapter there is a list of references to allow the reader to follow up any particular points he is interested in. The various chapters describe both the natural environment and the social and ecological problems of these desert fringes, and they indicate the kind of constraints any new policies must work within if they are to be acceptable to the local population. There are descriptions of the kind of modification to existing practices that might reduce the harmful effects of the severe over-grazing taking place and causing desertization. Naturally in a compilation of this type, there is considerable unevenness in the informativeness and usefulness of each chapter, but readers should find sections in most which will clarify their understanding of the problems facing graziers if t h e y are to accept good conservation practices. E. W. RUSSELL (Reading)