Encyclopedia of Theoretical Ecology

Encyclopedia of Theoretical Ecology

Copyright Date: 2012
Edition: 1
Pages: 848
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  • Book Info
    Encyclopedia of Theoretical Ecology
    Book Description:

    This major reference is an overview of the current state of theoretical ecology through a series of topical entries centered on both ecological and statistical themes. Coverage ranges across scales—from the physiological, to populations, landscapes, and ecosystems. Entries provide an introduction to broad fields such as Applied Ecology, Behavioral Ecology, Computational Ecology, Ecosystem Ecology, Epidemiology and Epidemic Modeling, Population Ecology, Spatial Ecology and Statistics in Ecology. Others provide greater specificity and depth, including discussions on the Allee effect, ordinary differential equations, and ecosystem services. Descriptions of modern statistical and modeling approaches and how they contributed to advances in theoretical ecology are also included. Succinct, uncompromising, and authoritative—a “must have” for those interested in the use of theory in the ecological sciences.

    eISBN: 978-0-520-95178-5
    Subjects: Ecology & Evolutionary Biology

Table of Contents

  1. Front Matter
    (pp. i-vi)
  2. Table of Contents
    (pp. vii-x)
    (pp. xi-xii)
    (pp. xiii-xx)
    (pp. xxi-xxii)
    (pp. xxiii-xxiv)
    Alan Hastings and Louis J. Gross
  7. A
    (pp. 1-63)

    Adaptive behavior is behavior that raises an animal’s fitness in its biotic and abiotic environment. The study of adaptive behavior is mainly the study of how behavior changes with environmental changes. Fitness is the relative contribution of an organism to genes in future generations. Because understanding fitness across the entire life of an organism is a daunting task (and tracking it across several generations even more so), researchers have commonly assumed a particular relationship between behavior in the short term and fitness. This has involved examining many behaviors using many fitness proxies and modeling techniques. This entry explores the simplifying...

  8. B
    (pp. 64-119)

    Bayesian statistics involves the specification of a joint probability model to describe the dependence among observable quantities (e.g., observed, or unobserved but predictable, data) and unobservable quantities (e.g., ecological model parameters, treatment effects, variance components). Inference about unobserved quantities is based on the posterior distribution (or posterior), which is the conditional probability distribution of the unobserved quantities given, or posterior to observing, the observed quantities. In principle, once a joint probability model is specified, the posterior follows via Bayes theorem, a well-known result from probability theory. In practice, except for relatively simple models, numerical methods must be used to approximate...

  9. C
    (pp. 120-162)

    Cannibalism is the consumption of one life stage of a species by another life stage. Although this may seem somewhat specialized, cannibalistic interactions are very common in natural systems. This is a subject that has played a very important role in the development of theoretical ecology because of the early experiments by Thomas Park withTriboliumand the development of corresponding models. More recent models of cannibalism have specifically included age or stage structure and have been used to understand population cycles as well as more complex dynamics including chaos.

    Some of the earliest laboratory experiments investigating population dynamics were...

  10. D
    (pp. 163-212)

    All processes take time to complete. While physical processes such as acceleration and deceleration take little time compared to the times needed to travel most distances, the times involved in biological processes such as gestation and maturation can be substantial when compared to the data-collection times in most population studies. Therefore, it is often imperative to explicitly incorporate these process times into mathematical models of population dynamics. These process times are often called delay times, and the models that incorporate such delay times are referred as delay differential equation (DDE) models.

    Recent theoretical and computational advancements in delay differential equations...

  11. E
    (pp. 213-275)

    Ecological economics is the study of the relationship between the economy and the ecosystem to promote the goal of sustainable development. While the field is over 40 years old, there is no agreed-upon definition, because the theories and methodologies of ecological economics draw from a number of social and natural science disciplines. This entry provides background on the emergence of the field as well as several competing interpretations of what constitutes ecological economics.

    The roots of ecological economics are in the theory and methodology of natural resource and environmental economics. However, ecological economics also accepts the existence of a limiting...

  12. F
    (pp. 276-329)

    Facilitation includes direct or indirect interactions between biological entities (i.e., cells, individuals, species, communities, or ecosystems) that benefit at least one participant in the interaction and cause harm to none. Research on ecological facilitation has steadily increased over the past three decades and is now appreciated as a fundamental process in ecology. Facilitation also has many important implications for problems in applied ecology and conservation.

    Understanding the processes governing species coexistence and community structure is a central goal of community ecology. Historically, most ecological research has focused on the negative effects of abiotic or biotic interactions as the primary drivers...

  13. G
    (pp. 330-345)

    Game theory was developed as a tool for rational decision making. Its basic concepts were later used in evolutionary game theory to describe the evolution of behavioral phenotypes. In the hands of evolutionary biologists, this merger of game theory and population dynamics became an important tool for analyzing frequency-dependent selection and social interaction.

    Game theory, as originally created by mathematicians and economists, addresses problems confronting decision makers with diverging interests (such as firms competing for a market, staff officers in opposing camps, or players engaged in a parlor game). The “players” have to choose between strategies whose payoff depends on...

  14. H
    (pp. 346-364)

    Mathematical theories of harvesting biological resources can be traced back to Martin Faustmann’s 1849 analysis of the optimal interval for the periodic harvesting of cultivated forest stands. Faustmann’s work presaged two different pathways that harvesting theory took a hundred years later in the early 1950s. These were R. J. H. Beverton and S. J. Holt’s cohort analysis and M. B. Schaefer’s maximum sustainable rent analysis. The latter matured largely through the work of C. W. Clark and colleagues in the early to mid-1970s into the field of mathematical bioeconomics. In the late 1970s, cohort theory was linked, as described below,...

  15. I
    (pp. 365-391)

    Individual-based ecology (IBE) refers to theoretical and applied ecology conducted in ways that recognize that individuals are important. IBE addresses how the dynamics of populations, communities, and ecosystems are affected by characteristics and behaviors of the individual organisms that make up these systems. The main tools of IBE are individual-based models (IBMs), simulation models that represent ecological systems as collections of explicit individuals and their environment. Theory in IBE consists of models ofindividualcharacteristics—especially adaptive behaviors—that have proven useful for explainingsystem-level phenomena, by testing them against empirical information. This kind of theory is unique in two...

  16. L
    (pp. 392-396)

    Spatial heterogeneity is ubiquitous in all ecological systems, underlining the significance of the pattern–process relationship and the scale of observation and analysis. Landscape ecology focuses on the relationship between spatial pattern and ecological processes on multiple scales. On the one hand, it represents a spatially explicit perspective on ecological phenomena. On the other hand, it is a highly interdisciplinary field that integrates biophysical and socioeconomic perspectives to understand and improve the ecology and sustainability of landscapes. Landscape ecology is still rapidly evolving, with a diversity of emerging ideas and a plurality of methods and applications.

    Landscapes are spatially heterogeneous...

  17. M
    (pp. 397-469)

    Marine reserves protect marine biodiversity from direct human impacts, primarily fishing, by providing spatial refuge to marine organisms. Most oceans, however, are affected by indirect threats as well, such as pollution and climate change, which cannot be effectively mitigated by restricting human access. Recently, there has been growing interest in ecosystem-based management (EBM) as a marine conservation strategy, because it aims to protect biodiversity and enhance ecosystem resilience by integrating management across sectors and addressing cumulative impacts of diverse human activities. While there are burgeoning bodies of literature on both marine reserve theory and EBM, there is little integration between...

  18. N
    (pp. 470-509)

    Ecological networks are abstract representations of nature describing species diversity, trophic (i.e., feeding) and nontrophic (e.g., facilitation, mutualism) relationships between species, and flows of energy and nutrients or individuals within an ecosystem. Traditionally, these features have been studied separately, such that each network describes just one type of interaction. Combining different types of interactions is more challenging, and there is a growing body of literature and methods attempting to tackle this problem.

    The search for unifying principles that give rise to the structure of ecological networks dates back to the 1970s. Networks are characterized by the components—the nodes—and...

  19. O
    (pp. 510-530)

    Ocean circulation describes the amplitude and pathways of fluid transport within the world’s oceans. It is responsible for the transport of mass and heat, chemical constituents, and biological organisms throughout the ocean basins. Oceanic motion contributes significantly to the planet’s meridional heat transport and helps define oceanic regions fertile for biological growth. In the time mean, a general structure to the circulation exists and can be described phenomenologically and dynamically. For example, the Gulf Stream is a very well-known feature in the western North Atlantic Ocean. This ocean current is among the fastest on Earth and is part of the...

  20. P
    (pp. 531-594)

    Pair approximations are analytical techniques for estimating the dynamics and equilibrium properties of network-based models. As the name implies, pair approximations capture the dynamics of the states of neighboring pairs of vertices in a network, as opposed to the dynamics of individual vertex states. These methods have been successfully applied to a variety of network-based ecological and evolutionary models, ranging from the evolution of cooperation to the spread of infectious disease.

    Many ecological processes occur on spatial scales that are much smaller than the entire geographic range of a population. To model such local interactions, populations are often represented as...

  21. Q
    (pp. 595-602)

    Quantitative genetics is the body of theory and methods used to study the inheritance of organismal traits that exhibit continuous variation. This variation is usually determined by contributions from alleles at many loci, each of small effect, as well as contributions from environmental sources. The statistical techniques of quantitative genetics have been used for decades to inform agricultural breeding practices and predict the response to artificially imposed selection. The same formalism has been utilized to develop models of quantitative trait evolution and to reconstruct the historical force of selection acting on traits. More recent advances, involving the identification of quantitative...

  22. R
    (pp. 603-636)

    Reaction–diffusion models are spatially explicit models for the dispersal, population dynamics, and interactions of organisms. They are deterministic and treat time and space as continuous variables, as opposed to integro-difference models, discrete diffusion models, interacting particle systems, cellular automata, and metapopulation models. They use partial differential equations or systems of such equations to describe how population densities vary in time and space. Reaction–diffusion models are used to understand various spatial phenomena in ecology. Specifically, they are used to characterize the minimal size that habitat patches must have to support populations, the speed of biological invasions, and the spontaneous...

  23. S
    (pp. 637-738)

    The evolution of sex is one of the largest and most fertile areas of research in evolutionary biology. It encompasses multiple unresolved questions involving a number of evolutionary steps: the evolution of the recombination machinery, the evolution of meiosis, the differentiation into sexes, the differentiation of gametes produced by each sex, and, finally, the maintenance of sex despite its two-fold cost.

    Sex and recombination through meiosis are confined to eukaryotes. However, a complex molecular machinery enabling homologous recombination between different DNA molecules was already present in prokaryotes long before the first eukaryotes evolved. The original function of this machinery lies...

  24. T
    (pp. 739-764)

    All organisms need food to grow, reproduce, and survive. The availability of food therefore determines the ecological success of species in a fundamental way. For this reason, it is commonly accepted that species population dynamics are regulated or controlled by the bottom-up effects of the availability of resources. In addition to (and not in contrast to) this bottom-up control, species populations can also be regulated, or controlled, top-down, that is, by their predators.

    “Why is the world green?” The most well-known answer to this question is that herbivores are controlled by predators, thereby releasing green plants from herbivorous grazing. The...

  25. U
    (pp. 765-770)

    Urban ecology is the scientific study of the processes influencing the distribution and abundance of orga nisms, the interactions among organisms and between organisms, and the transformation and flux of energy and matter in urban and urbanizing systems. To understand the structure and dynamics of urban systems they must be recognized as social-ecological systems that integrate socioeconomic drivers and responses with ecological structures and functions. This integration requires approaches and applications of theory from a variety of disciplines, but the need for novel ecological theory is much debated in this nascent field.

    Ecological concepts were first applied to the urban...

    (pp. 771-802)
  27. INDEX
    (pp. 803-823)