Herbivores: Between Plants and Predators

H. Olff, V.K. Brown ?25 (paperback), ISBN 0-632-05204-X. This book presents the invited papers from the British Ecological Society's 38th Symposium, of the same title, which was arranged jointly with the Netherlands Ecological Society and held at Wageningen Agricultural University in 1997. The stated aim of the book (and indeed the conference) was to ‘bring together authors from different disciplines…taking herbivores as the point of focus’, to give an ‘up-to-date overview of knowledge in the field and (to) suggest many interesting directions for future research’. The approach taken was to select five specific subjects for ‘comprehensive review’ within each of four Sections which cover ‘Plants shaping the evolution of insect herbivores’, ‘Herbivores and vegetation succession’, ‘Scaling up from food intake to community dynamics in vertebrate herbivores’ and the ‘Effect of higher trophic levels on plant–herbivore interactions’. Interestingly, all except two of the authors come from only four countries: the Netherlands, USA, Canada or UK. The first Section starts with an enthusiastic overview by the session organisers – an excellent way to begin and a flavour reflected by most of the papers in this Section. The first chapter gives a clear, well laid out discussion on the current state of insect/plant coevolution research. Chapters 2 and 4 present interesting and contrasting approaches to insect herbivore–host plant interactions. Insect resistance to plant allelochemicals and insecticides are discussed in Chapter 3, focusing on one important type of biochemical resistance (P450s). The Section ends with a thoughtful examination of the roles of both direct and indirect plant defence in plant–insect interactions. The first chapter of Section 2 presents some interesting ideas on herbivore–plant diversity relationships. This is followed by an informative review of the important and often under-rated impacts of below-ground herbivory on plant succession (Chapter 7). Chapter 8 presents a new model of plant–herbivore interactions along productivity gradients. Cyclic grazing and manipulation of the food resource by vertebrate herbivores are discussed in Chapter 9, and the final chapter gives an excellent, wide-ranging discussion of herbivores and trophic cascades. The third Section starts with a thorough review of digestive and ingestive adaptations to low-quality forage. Functional responses to resource complexity are the central issue discussed in Chapter 12. Chapters 13 and 14 present two quite different but equally illuminating model developments: the first synthesizing food intake and diet selection processes, scaling up from functional to numerical herbivore response; the second focusing on physiological flexibility and foraging behaviour in birds. The final chapter in this Section moves even further up the scale with a challenging paper on the complexity of vertebrate community dynamics. The final Section rounds the book off well, with four informative chapters adding valuable discussion to the debate on bottom-up or top-down forces in plant–herbivore systems. In Chapter 16, evolutionary and ecological consequences of plant–carnivore interactions are examined. Chapter 17 explores the importance of individual attributes in consumer–resource interactions. This is followed by a discussion of individual-based modelling as an integrative approach (Chapter 18). The Section (and book) finishes with predator control and trophic cascades, returning refreshingly to the importance of below-ground processes in plant–herbivore systems. The book is well produced, with a clear, albeit rather small, typeface and well reproduced tables and figures. However, the mixture of full justification (most) and left justification (numbered paragraphs, figure legends, references, etc.) gives parts of the book an untidy look. Most chapters are well referenced and there are useful author and subject indices at the end. Herbivory is a huge and ambitious topic to tackle so widely in just 19 conference papers, albeit restricting it to terrestrial ecosystems. But the choice and division of subtopics works well and the book certainly gives an interesting and state-of-the-art flavour of a wide range of subjects, albeit not a fully comprehensive overview. This is an extremely useful text for students and researchers at all levels. Inevitably, with such a wide coverage, this book is likely to be partially, rather than fully read by many users, especially those already well specialized. Unfortunately, most chapters (with the exception of those of the Editors!) do not really ‘emphasize the links between these different fields of interest’, as stated in the summary of the book. However, I would encourage all readers to at least dip into the other topics, as most chapters are very readable (so important, especially in an unfamiliar subject), interesting and informative. I have certainly enriched my knowledge from a full reading of the book!