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标签:ecology

  • The Unified Neutral Theory of Biodiversity and Biogeography

    作者:Stephen P. Hubbell

    Despite its supreme importance and the threat of its global crash, biodiversity remains poorly understood both empirically and theoretically. This ambitious book presents a new, general neutral theory to explain the origin, maintenance, and loss of biodiversity in a biogeographic context. Until now biogeography (the study of the geographic distribution of species) and biodiversity (the study of species richness and relative species abundance) have had largely disjunct intellectual histories. In this book, Stephen Hubbell develops a formal mathematical theory that unifies these two fields. When a speciation process is incorporated into Robert H. MacArthur and Edward O. Wilson's now classical theory of island biogeography, the generalized theory predicts the existence of a universal, dimensionless biodiversity number. In the theory, this fundamental biodiversity number, together with the migration or dispersal rate, completely determines the steady-state distribution of species richness and relative species abundance on local to large geographic spatial scales and short-term to evolutionary time scales. Although neutral, Hubbell's theory is nevertheless able to generate many nonobvious, testable, and remarkably accurate quantitative predictions about biodiversity and biogeography. In many ways Hubbell's theory is the ecological analog to the neutral theory of genetic drift in genetics. The unified neutral theory of biogeography and biodiversity should stimulate research in new theoretical and empirical directions by ecologists, evolutionary biologists, and biogeographers. Table of Contents: Preface ix 1.MacArthur and Wilson's Radical Theory 3 2.On Current Theories of Relative Species Abundance 30 3.Dynamical Models of the Relative Abundance of Species 48 4.Local Community Dynamics under Ecological Drift 76 5.Metacommunity Dynamics and the Unified Theory 113 6.The Unified Theory and Dynamical Species-Area Relationships 152 7.Metapopulations and Biodiversity on the Metacommunity Landscape 202 8.Speciation, Phylogeny, and the Evolution of Metacommunity Biodiversity 231 9.Sampling, Parameter Estimation, and the Generality of the Unified Theory 281 10.Reconciling Dispersal-Assembly and Niche-Assembly Theories 319 Literature Cited 347 Index 371
  • The Bet

    作者:Sabin, Paul

    In 1980, the iconoclastic economist Julian Simon challenged celebrity biologist Paul Ehrlich to a bet. Their wager on the future prices of five metals captured the public's imagination as a test of coming prosperity or doom. Ehrlich, author of the landmark book The Population Bomb, predicted that rising populations would cause overconsumption, resource scarcity and famine - with apocalyptic consequences for humanity. Simon optimistically countered that human welfare would flourish thanks to flexible markets, technological change, and our collective ingenuity. Simon and Ehrlich's debate reflected a deepening national conflict over the future of the planet. The Bet weaves the two men's lives and ideas together with the era's partisan political clashes over the environment and the role of government. In a lively narrative leading from the dawning environmentalism of the 1960s through the pivotal presidential contest between Jimmy Carter and Ronald Reagan and on into the 1990s, Paul Sabin shows how the fight between Ehrlich and Simon - between environmental fears and free-market confidence - helped create the gulf separating environmentalists and their critics today. Drawing insights from both sides, Sabin argues for using social values, rather than economic or biological absolutes, to guide society's crucial choices relating to climate change, the planet's health, and our own.
  • The Ecological Approach To Visual Perception

    作者:James J. Gibson

    This is a book about how we see: the environment around us (its surfaces, their layout, and their colors and textures); where we are in the environment; whether or not we are moving and, if we are, where we are going; what things are good for; how to do things (to thread a needle or drive an automobile); or why things look as they do. The basic assumption is that vision depends on the eye which is connected to the brain. The author suggests that natural vision depends on the eyes in the head on a body supported by the ground, the brain being only the central organ of a complete visual system. When no constraints are put on the visual system, people look around, walk up to something interesting and move around it so as to see it from all sides, and go from one vista to another. That is natural vision -- and what this book is about.