FOREST CANOPIES

With this title you probably immediately think of those people performing their hair-raising, adventurous acrobatics in the tops of towering tropical rain forest trees, using flexible steel frames, towers, cranes, telescoping ladders on second-hand fire engines, balloons, zeplins, airborne rafts, suspended catwalks, mountaineering gear, etc. But look again at the title and you see that the book has no restriction to the tropics.

Then read this interesting book in the Physiological Ecology series of Academic Press, and you will again be surprised: there is hardly any attention for non-tropical forest canopies. That, at least, is in line with the foreword and preface, where climbing the huge tropical rain forest trees is enthusiastically presented as the great excitement of the past two or three decades and as a present-day extension of the age of exploration.

This book makes very interesting reading. It is rich in contents, though not at all comprehensive. Some topics are even surprisingly missing (e.g., termites, amphibians, birds, bats, primates, canopy dynamics). There is great diversification among the authors in their approaches of their topics, and again that makes the reading good and lively.

As a consequence, this is a stimulating book, very suitable to use in classes and discuss with students, not just the factual contents of the text, but also the approach and orientation with which the specialist authors present their cases. This book did not result from any special meeting or workshop. The editors just asked their authors for contributions. That makes it puzzling why some important topics are not covered. It also exposes the strong bias in the selection of authors: nearly all of the 31 authors are from the USA.

The book has 4 parts. The first part, on structure and function, starts with an entertaining and excitingly illustrated chapter on canopy access techniques. Part 1 also contains the by now well-known architectural analysis of tropical trees, an interesting chapter on heat and mass exchange between the forest canopy and the atmosphere, and an extensively documented chapter on canopy structure and microclimatic gradients.

The second part deals with the organisms: 7 chapters on animals (arthropod biodiversity, ants, lizards, access techniques and birds, small mammals, larger mammals, mites on the leaf surfaces), 5 chapters on plants (vascular epiphytes, non-vascular epiphytes, hemi-epiphytes, mistletoes, vines).

In some cases these chapters are mainly updated sum-ups that by and large duplicate available other reviews by the same author. Some other chapters give fascinating and refreshing new views. I particularly liked the galvanizing story on the myriads of mites on the leaf surfaces, the informative chapters on hemi-epiphytes and on (Australian) mistletoes, and the full account on non-vascular epiphytes.

Part 3 covers the processes, with worthwhile accounts on photosynthesis, herbivory, reproduction and dispersal, and the role of epiphytes in nutrient cycles. I particularly like the latter two chapters, both of them well-structured and very full of information. Part 4 is labeled human impacts, but it contains a surprising assembly of chapters on ethnobotany of epiphytes and lianas, collecting plant material, eco-tourism, and a summary of ‘canopy science’ by the editors. As I already said, this is a stimulating book, interesting for the reader, and useful as a text to discuss in classes on (tropical rain) forest ecology.