Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

The Theory of Island Biogeography

An essential textbook for any student or researcher in biology needing to design experiments, sample programs or analyse the resulting data The text begins with a revision of estimation and hypothesis testing methods, covering both classical and Bayesian philosophies, before advancing to the analysis of linear and generalized linear models Topics covered include linear and logistic regression, simple and complex ANOVA models (for factorial, nested, block, split-plot and repeated measures and covariance designs), and log-linear models Multivariate techniques, including classification and ordination, are then introduced Special emphasis is placed on checking assumptions, exploratory data analysis and presentation of results The main analyses are illustrated with many examples from published papers and there is an extensive reference list to both the statistical and biological literature The book is supported by a website that provides all data sets, questions for each chapter and links to software

/pdf/experimental-design-and-data-analysis-for-biologists-8ybva8d53x.pdf

Experimental Design and Data Analysis for Biologists

http://www.maths.qmul.ac.uk/%7Elatora/report_06.pdf

Complex networks: Structure and dynamics

Humans are altering the composition of biological communities through a variety of activities that increase rates of species invasions and species extinctions, at all scales, from local to global. These changes in components of the Earth's biodiversity cause concern for ethical and aesthetic reasons, but they also have a strong potential to alter ecosystem properties and the goods and services they provide to humanity. Ecological experiments, observations, and theoretical developments show that ecosystem properties depend greatly on biodiversity in terms of the functional characteristics of organisms present in the ecosystem and the distribution and abundance of those organisms over space and time. Species effects act in concert with the effects of climate, resource availability, and disturbance regimes in influencing ecosystem properties. Human activities can modify all of the above factors; here we focus on modification of these biotic controls. The scientific community has come to a broad consensus on many aspects of the re- lationship between biodiversity and ecosystem functioning, including many points relevant to management of ecosystems. Further progress will require integration of knowledge about biotic and abiotic controls on ecosystem properties, how ecological communities are struc- tured, and the forces driving species extinctions and invasions. To strengthen links to policy and management, we also need to integrate our ecological knowledge with understanding of the social and economic constraints of potential management practices. Understanding this complexity, while taking strong steps to minimize current losses of species, is necessary for responsible management of Earth's ecosystems and the diverse biota they contain.

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Effects of biodiversity on ecosystem functioning: a consensus of current knowledge

The stable isotopes of nitrogen (8'5N) and carbon (8'3C) provide powerful tools for estimating the trophic positions of and carbon flow to consumers in food webs; however, the isotopic signature of a consumer alone is not generally sufficient to infer trophic position or carbon source without an appropriate isotopic baseline. In this paper, I develop and discuss methods for generating an isotopic baseline and evaluate the assump- tions required to estimate the trophic position of consumers using stable isotopes in multiple ecosystem studies. I test the ability of two primary consumers, surface-grazing snails and filter-feeding mussels, to capture the spatial and temporal variation at the base of aquatic food webs. I find that snails reflect the isotopic signature of the base of the littoral food web, mussels reflect the isotopic signature of the pelagic food web, and together they provide a good isotopic baseline for estimating trophic position of secondary or higher trophic level consumers in lake ecosystems. Then, using data from 25 north temperate lakes, I evaluate how 815N and 8'3C of the base of aquatic food webs varies both among lakes and between the littoral and pelagic food webs within lakes. Using data from the literature, I show that the mean trophic fractionation of b'5N is 3.4%o (1 SD = 1%M) and of 8'3C is 0.4%o (1 SD = 1.3%o), and that both, even though variable, are widely applicable. A sen- sitivity analysis reveals that estimates of trophic position are very sensitive to assumptions about the trophic fractionation of '5 N, moderately sensitive to different methods for gen- erating an isotopic baseline, and not sensitive to assumptions about the trophic fractionation of 8'3C when 8'3C is used to estimate the proportion of nitrogen in a consumer derived from two sources. Finally, I compare my recommendations for generating an isotopic baseline to an alternative model proposed by M. J. Vander Zanden and J. B. Rasmussen. With an appropriate isotopic baseline and an appreciation of the underlying assumptions and model sensitivity, stable isotopes can help answer some of the most difficult questions in food web ecology.

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Using stable isotopes to estimate trophic position: models, methods, and assumptions

Interactions between species are usually categorized as either competition (-), predation/parasitism (+ -), mutualism (+ +), commensalism (+ 0), or amensalism (-0). Intraguild predation (IGP) is a combination of the first two, that is, the killing and eating of species that use similar, often limiting, resources and are thus potential competitors. Intraguild predation is distinguished from traditional concepts of competition by the immediate energetic gains for one participant (the predator). It differs from classical predation because the act reduces potential exploitation competition. Thus, its impact on population dynamics is more complex than either competition or predation alone (see below). Our purpose is to document the ubiquity and importance of intraguild predation and to establish a theoretical framework for its analysis. A taxonomically widespread interaction, IGP significantly affects the distribution, abundance, and evolution of many species. One intriguing conclusion is that IGP promotes the occurrence of alternative stable states in many circumstances. Although sometimes recognized by theoreticians and empirically oriented biologists, this is the first synthesis of IGP into a general work.

https://www.jstor.org/stable/info/2097094

THE ECOLOGY AND EVOLUTION OF INTRAGUILD PREDATION: Potential Competitors That Eat Each Other

Food webs in nature have multiple, reticulate connections between a diversity of consumers and resources. Such complexity affects web dynamics: it first spreads the direct effects of consumption and productivity throughout the web rather than focusing them at particular "trophic levels." Second, consumer densities are often donor controlled with food from across the trophic spectrum, the herbivore and detrital channels, other habitats, life-history omnivory, and even trophic mutualism. Although consumers usually do not affect these resources, increased numbers often allow consumers to depress other resources to levels lower than if donor-controlled resources were absent. We propose that such donor-controlled and "multichannel" omnivory is a general feature of consumer control and central to food web dynamics. This observation is contrary to the normal practice of inferring dynamics by simplifying webs into a few linear "trophic levels," as per "green world" theories. Such theories do not accommodate commo...

Food Web Complexity and Community Dynamics

Intraspecific predation, the process of both killing and eating an individual of the same species, is a significant and widespread process that until recently has not received the attention it merits. It is a major factor in the biology of many species and may influence population structure, life history, competition for mates and resources, and behavior. It is commonly observed among many animals: For this review I read over 900 papers describing such predation in about 1300 species. Laurel Fox's 1975 review of cannibalism (54) should be read for additional information. Here I attempt to present new or different data, references, and ideas. One of my purposes is to establish a theoretical framework for the organization and interpretation of the numerous observations of intraspecific predation. Certain topics included here are speculation intended to spark interest and indicate important problems that need further research. Because of page limitations many appropriate and important citations are not cited here but may be found elsewhere as indicated by "& incl. refs."

The Evolution and Dynamics of Intraspecific Predation

Many important issues in community ecology revolve around the interplay of competition and predation Species that compete may also be locked in predator-prey interactions, a mixture of competition and predation known as "intraguild predation" (IGP) There is growing evidence for the importance of IGP in many natural communities, yet little formal ecological theory addresses this particular blend of interactions In this article, we explore the consequences of incorporating IGP into standard models of exploitative competition and food chains (a general resource-consumer model, a Lotka-Volterra food chain model, and Schoener's exploitative competition model) Our theoretical analyses suggest a general criterion for coexistence in IGP systems: the intermediate species (the prey in intraguild predation) should be superior at exploitative competition for the shared resource, whereas the top species (the predator) should gain significantly from its consumption of the intermediate species Along gradients in en

A theoretical framework for intraguild predation

Food webs in the real world are much more complex than food-web literature would have us believe. This is illustrated by the web of the sand community in the Coachella Valley desert. The biota include 174 species of vascular plants, 138 species of vertebrates, more than 55 species of arachnids, and an unknown (but great) number of microorganisms, insects (2,000-3,000 estimated species), acari, and nematodes. Trophic relations are presented in a series of nested subwebs and delineations of the community. Complexity arises from the large number of interactive species, the frequency of omnivory, age structure, looping, the lack of compartmentalization, and the complexity of the arthropod and soil faunas. Web features found in the Coachella also characterize other communities and should produce equivalently complex webs. If anything, diversity and complexity in most nondesert habitats are greater than those in deserts. Patterns from the Coachella web are compared with theoretical predictions and "empirical ge...

Gary A. Polis

Papers

THE ECOLOGY AND EVOLUTION OF INTRAGUILD PREDATION: Potential Competitors That Eat Each Other

Food Web Complexity and Community Dynamics

The Evolution and Dynamics of Intraspecific Predation

A theoretical framework for intraguild predation

Complex trophic interactions in deserts: an empirical critique of food-web theory