The question "Why are there so many species?" has puzzled ecologist for a long time. Initially, an academic question, it has gained practical interest by the recent awareness of global biodiversity loss. Species diversity in local ecosystems has always been discussed in relation to the problem of competi tive exclusion and the apparent contradiction between the competitive exclu sion principle and the overwhelming richness of species found in nature. Competition as a mechanism structuring ecological communities has never been uncontroversial. Not only its importance but even its existence have been debated. On the one extreme, some ecologists have taken competi tion for granted and have used it as an explanation by default if the distribu tion of a species was more restricted than could be explained by physiology and dispersal history. For decades, competition has been a core mechanism behind popular concepts like ecological niche, succession, limiting similarity, and character displacement, among others. For some, competition has almost become synonymous with the Darwinian "struggle for existence", although simple plausibility should tell us that organisms have to struggle against much more than competitors, e.g. predators, parasites, pathogens, and envi ronmental harshness.

It is not often that one has the opportunity to send a public birthday greet ing to a friend and colleague of many years, and to congratulate him on having reached the age of reason. In fact it happens only once, and comes then as a surprise. Surely it was only a few years ago that we sat together at an International Genetics Congress in Ithaca, and only yesterday that we became members of the same department. The eighth floor of Schermerhorn Hall had a north end where the flies were and a south end furnished with mice, and in between, a seminar room and laboratory. There the distances were short and the doors open and the coffee pot busy. But it now appears that yesterday has fallen thirty years behind and that we have grown up. I find it interesting and appropriate that Dobzhansky's lifetime spans the period of maturation of the fields to which this volume is devoted. This is true in a chronological sense for his birth occurred in the same year, 1900, in which modern genetics began. The rediscovery of Mendel's princi ples and the interpretation of the nature of heredity and variation to which this event led were necessary prerequisites to the development of evolution ary biology as presented in this collection of essays.

This volume considers how media firms, as well as entire industries, exist and persist over time despite what often seems to be intense competition for such resources as audiences and advertisers. Addressing competition within and among media organizations and industries, including broadcasting, cable, and the Internet, author John W. Dimmick studies the media industries through the niche theory lens, developed by bioecologists to explain competition and coexistence. He examines the targets of the different media--audience, advertisers, money--and how they compete, using examples from a variety of studies. Each chapter incorporates relevant economic constructs into the analytic framework. This approach includes the use of economics of scale to explain selection and firm mortality in newspapers and movie theaters; the application of the transaction costs concept to explicate the rise of advertising agencies; the employment of the strategic group concept in analyzing the niche breadth strategy; and the measurement of gratifications-utilities. A comprehensive overview of the determinants of media competition and coexistence, Media Competition and Coexistence: The Theory of the Niche offers unique insights for scholars, students, researchers, and practitioners in media economics, management, and business.

The Princeton Guide to Ecology is a concise, authoritative one-volume reference to the field's major subjects and key concepts. Edited by eminent ecologist Simon Levin, with contributions from an international team of leading ecologists, the book contains more than ninety clear, accurate, and up-to-date articles on the most important topics within seven major areas: autecology, population ecology, communities and ecosystems, landscapes and the biosphere, conservation biology, ecosystem services, and biosphere management. Complete with more than 200 illustrations (including sixteen pages in color), a glossary of key terms, a chronology of milestones in the field, suggestions for further reading on each topic, and an index, this is an essential volume for undergraduate and graduate students, research ecologists, scientists in related fields, policymakers, and anyone else with a serious interest in ecology. Explains key topics in one concise and authoritative volume Features more than ninety articles written by an international team of leading ecologists Contains more than 200 illustrations, including sixteen pages in color Includes glossary, chronology, suggestions for further reading, and index Covers autecology, population ecology, communities and ecosystems, landscapes and the biosphere, conservation biology, ecosystem services, and biosphere management

A new perspective on the biological roots of competition from the author of Anarchy Evolution and Cornell lecturer

Provides a current, critical review of the importance of interspecific competition, considering the evolutionary effects of interspecific competition, its importance in structuring communities, and influence on the traits of individual species.

There isprobably no more appropriate location to hold a course on mathematical ecology than Italy, the countryofVito Volterra, a founding father ofthe subject. The Trieste 1982Autumn Course on Mathematical Ecology consisted of four weeksofvery concentrated scholasticism and aestheticism. The first weeks were devoted to fundamentals and principles ofmathematicalecology. A nucleusofthe material from the lectures presented during this period constitutes this book. The final week and a half of the Course was apportioned to the Trieste Research Conference on Mathematical Ecology whose proceedings have been published as Volume 54, Lecture Notes in Biomathematics, Springer-Verlag. The objectivesofthe first portionofthe course wereambitious and, probably, unattainable. Basic principles of the areas of physiological, population, com munitY, and ecosystem ecology that have solid ecological and mathematical foundations were to be presented. Classical terminology was to be introduced, important fundamental topics were to be developed, some past and some current problems of interest were to be presented, and directions for possible research were to be provided. Due to time constraints, the coverage could not be encyclopedic;many areas covered already have merited treatises of book length. Consequently, preliminary foundation material was covered in some detail, but subject overviewsand area syntheseswerepresented when research frontiers were being discussed. These lecture notes reflect this course philosophy.

This book clearly describes the many applications of graph theory to ecological questions, providing instruction and encouragement to researchers.