Now that so many ecosystems face rapid and major environmental change, the ability of species to respond to these changes by dispersing or moving between different patches of habitat can be crucial to ensuring their survival. Understanding dispersal has become key to understanding how populations may persist. Dispersal Ecology and Evolution provides a timely and wide-ranging overview of the fast expanding field of dispersal ecology, incorporating the very latest research. The causes, mechanisms, and consequences of dispersal at the individual, population, species, and community levels are considered. Perspectives and insights are offered from the fields of evolution, behavioural ecology, conservation biology, and genetics. Throughout the book theoretical approaches are combined with empirical data, and care has been taken to include examples from as wide a range of species as possible - both plant and animal.

This book provides information on the historical and theoretical perspectives of biodiversity and ecology in tropical forests, plant and animal behaviour towards seed dispersal and plant-animal interactions within forest communities, consequences of seed dispersal, and conservation, biodiversity and management.

Dispersal has become central to many questions in theoretical and applied ecology in recent years. In this volume a team of leading ecologists aim to provide the advanced student and researcher with a comprehensive review of dispersal and its implications for modern ecology.

Propagule, evolution.

Any scientific discipline needs a theoretical framework to guide its development and to sharpen the questions its researchers pursue. In biology, evolution is the grand theoretical framework, and an his torical perspective is necessary to understand present-day biological conditions. In its formative years, the modern study of the fruit-frugivore mutualism was guided by the 'specialist-generalist' paradigm developed by D. Snow, D. McKey, and H. Howe. Howe reviews the current status of this evolution ary paradigm and points out that it has been dismissed by many workers before being adequately tested. This is because ecologists working with the tropical plants and frugivorous birds for which the paradigm was originally developed rarely measure the seed dispersal effectiveness of different disperser species. He indicates that this paradigm still has heuristic value and suggests that several additional ecological paradigms, including the concept ofkeystone species ofplants and frugivores and the role that frugivores play in density-dependent mortality in tropical trees, are worth studying. The concept of seed dispersal quality has been central to discussions of fruit-frugivore coevolution. Schupp thoroughly reviews data bearing on this concept, constructs a hierarchical framework for viewing disperser effectiveness, and points out that disperser effectiveness depends on both the quantity and quality of seed dispersal. Effectiveness, in turn, affects both evolutionary and ecological relationships between dispersers and their food plants.

4.1.1 Demographic significance Confined populations grow more rapidly than populations from which dispersal is permitted (Lidicker, 1975; Krebs, 1979; Tamarin et at., 1984), and demography in island populations where dispersal is restricted differs greatly from nearby mainland populations (Lidicker, 1973; Tamarin, 1977, 1978; Gliwicz, 1980), clearly demonstrating the demographic signi ficance of dispersal. The prevalence of dispersal in rapidly expanding populations is held to be the best evidence for presaturation dispersal. Because dispersal reduces the growth rate of source populations, it is generally believed that emigration is not balanced by immigration, and that mortality of emigrants occurs as a result of movement into a 'sink' of unfavourable habitat. If such dispersal is age- or sex-biased, the demo graphy of the population is markedly affected, as a consequence of differ ences in mortality in the dispersive sex or age class. Habitat heterogeneity consequently underlies this interpretation of dispersal and its demographic consequences, although the spatial variability of environments is rarely assessed in dispersal studies.

Reviewers from diverse branches of botany have exerted pressure to have chapters dealing with their field extended. If only to cover his incompetence, the author could not accede to these requests. Nor was it possible to respond to Eastern European urgings to extend the classificatory terminology, especially in ChapterX. He is grateful for indications of factual shortcomings in the chosen field, especially for those by Dr. RUDOLF SCHMID (Ann Arbor), who provided exten sive comment. L. VAN DER PIlL The Hague, spring 1972 Preface to the First Edition The work offered here is a companion volume to the work by K. FAEGRI and 1. VAN DER PIJL, Principles of Pollination Ecology, whim. deals with the preced ing phase of reproduction in plants. In the present work too, the emphasis is on principles and ecology. It is neither an enumeration of mechanisms, nor a compilation of cases. RIDLEY'S monumental work The Dispersal of Plants Throughout the World comprises 700 large pages of small print, and research has proceeded since then. Though this work is more than just a compilation and contains much insight and thoughts on principles in addition to reviews, its completeness hinders its use as a text book. As a reference work, it is unsurpassed and the writer made frequent use of it. The writer paid special attention to functional backgrounds for the use of taxonomists working with "characters" and to biosystematics at the macro-level.