Often the meanings of words are changed subtly for interesting reasons. The implication of the word 'community' has changed from including all the organisms in an area to only those species at a particular trophic level (and often a taxonomically restricted group), for example, 'bird-community'. If this observation is correct, its probable cause is the dramatic growth in our knowledge of the ecological patterns along trophic levels (I call these horizontal patterns) and the processes that generate them. This book deals with vertical patterns - those across trophic levels -and tries to compensate for their relative neglect. In cataloging a dozen vertical patterns I hope to convince the reader that species interactions across trophic levels are as patterned as those along trophic levels and demand explanations equally forcefully. But this is not the only objective. A limited number of processes shape the patterns of species interaction; to demonstrate their existence is an essential step in understanding why ecosystems are the way they are. To achieve these aims I must resort to both mathematical techniques to develop theories and statistical techniques to decide between rival hypotheses. The level of mathematics is likely to offend nearly everyone. Some will find any mathematics too much, while others will consider the material to be old, familiar ground and probably explained with a poor regard for rigour and generality.
"Human impacts are dramatically altering our natural ecosystems. The implications of these human impacts on the sustainability and functioning of these amazingly complex entities remains uncertain. As a result, food web theory has experienced a proliferation of research that seeks to address this critical area. This book synthesizes modern and classical results into a general theory. Finally, this book takes this general theoretical framework and discusses the implications of human impact for the stability and sustainability of ecological systems"--
Multispecies Assemblages, Ecosystem Development and Environmental Change
Author: Peter C de Ruiter,Volkmar Wolters,John C Moore
Dynamic Food Webs challenges us to rethink what factors may determine ecological and evolutionary pathways of food web development. It touches upon the intriguing idea that trophic interactions drive patterns and dynamics at different levels of biological organization: dynamics in species composition, dynamics in population life-history parameters and abundances, and dynamics in individual growth, size and behavior. These dynamics are shown to be strongly interrelated governing food web structure and stability and the role of populations and communities play in ecosystem functioning. Dynamic Food Webs not only offers over 100 illustrations, but also contains 8 riveting sections devoted to an understanding of how to manage the effects of environmental change, the protection of biological diversity and the sustainable use of natural resources. Dynamic Food Webs is a volume in the Theoretical Ecology series. Relates dynamics on different levels of biological organization: individuals, populations, and communities Deals with empirical and theoretical approaches Discusses the role of community food webs in ecosystem functioning Proposes methods to assess the effects of environmental change on the structure of biological communities and ecosystem functioning Offers an analyses of the relationship between complexity and stability in food webs
Food webs have now been addressed in empirical and theoretical research for more than 50 years. Yet, even elementary foundational issues are still hotly debated. One difficulty is that a multitude of processes need to be taken into account to understand the patterns found empirically in the structure of food webs and communities. Food Webs and Biodiversity develops a fresh, comprehensive perspective on food webs. Mechanistic explanations for several known macroecological patterns are derived from a few fundamental concepts, which are quantitatively linked to field-observables. An argument is developed that food webs will often be the key to understanding patterns of biodiversity at community level. Key Features: Predicts generic characteristics of ecological communities in invasion-extirpation equilibrium. Generalizes the theory of competition to food webs with arbitrary topologies. Presents a new, testable quantitative theory for the mechanisms determining species richness in food webs, and other new results. Written by an internationally respected expert in the field. With global warming and other pressures on ecosystems rising, understanding and protecting biodiversity is a cause of international concern. This highly topical book will be of interest to a wide ranging audience, including not only graduate students and practitioners in community and conservation ecology but also the complex-systems research community as well as mathematicians and physicists interested in the theory of networks. "This is a comprehensive work outlining a large array of very novel and potentially game-changing ideas in food web ecology." —Ken Haste Andersen, Technical University of Denmark "I believe that this will be a landmark book in community ecology … it presents a well-established and consistent mathematical theory of food-webs. It is testable in many ways and the author finds remarkable agreements between predictions and reality." —Géza Meszéna, Eötvös University, Budapest
Seals, otters, oysters, fish, pelicans, and sharks are a few of the animals that make up an ocean food web. But did you know that almost all ocean creatures depend on algae to live? Or that bacteria, crabs, and lobsters break down dead plants and animals into nutrients? See ocean food webs in action in this fascinating book.
Snakes, lizards, rabbits, mice, mountain lions, and hawks are some of the many animals that make up a desert food web. But do you know how desert animals depend on cactuses, grasses, and other plants to stay alive? Or why tiny insects, fungi, and bacteria may be among the most important living things in a desert? See desert food webs in action in this fascinating book.
Reflecting the recent surge of activity in food web research fueled by new empirical data, this authoritative volume successfully spans and integrates the areas of theory, basic empirical research, applications, and resource problems. Written by recognized leaders from various branches of ecological research, this work provides an in-depth treatment of the most recent advances in the field and examines the complexity and variability of food webs through reviews, new research, and syntheses of the major issues in food web research. Food Webs features material on the role of nutrients, detritus and microbes in food webs, indirect effects in food webs, the interaction of productivity and consumption, linking cause and effect in food webs, temporal and spatial scales of food web dynamics, applications of food webs to pest management, fisheries, and ecosystem stress. Three comprehensive chapters synthesize important information on the role of indirect effects, productivity and consumer regulation, and temporal, spatial and life history influences on food webs. In addition, numerous tables, figures, and mathematical equations found nowhere else in related literature are presented in this outstanding work. Food Webs offers researchers and graduate students in various branches of ecology an extensive examination of the subject. Ecologists interested in food webs or community ecology will also find this book an invaluable tool for understanding the current state of knowledge of food web research.
Scientists rely on food webs—complex networks that trace the flow of nutrients and energy between species and through ecosystems—to understand the infrastructure of ecological communities. But given the complexities of food webs—think of following the flow of nutrients through the microbes, fungi, roots, worms, ants, and birds that pass over or through a single cubic meter of prairie soil—it's not difficult to see why most experiments on food-web dynamics focus on small, local habitats. Yet as this book convincingly shows, important insights come when scientists expand the temporal and spatial scope of their research to look at the ways energy, organisms, nutrients, and pollutants flow not just at the local level, but across whole landscapes—between and among food webs in a wide variety of habitats. Paying special attention to the fertile boundaries between terrestrial, freshwater, and marine ecosystems, Food Webs at the Landscape Level not only shows what this new methodology means for ecology, conservation, and agriculture but also serves as a fitting tribute to Gary Polis and his major contributions to the field.
Explains the predator-prey relationships that all living things are a part of, represented by the food chains and food webs in a variety of habitats, how everything is connected, and how every living organism plays a role.
This novel book bridges the gap between the energetic and species approaches to studying food webs, addressing many important topics in ecology. Species, matter, and energy are common features of all ecological systems. Through the lens of complex adaptive systems thinking, the authors explore how the inextricable relationship between species, matter, and energy can explain how systems are structured and how they persist in real and model systems. Food webs are viewed as open and dynamic systems. The central theme of the book is that the basis of ecosystem persistence and stability rests on the interplay between the rates of input of energy into the system from living and dead sources, and the patterns in utilization of energy that result from the trophic interactions among species within the system. To develop this theme, the authors integrate the latest work on community dynamics, ecosystem energetics, and stability. In so doing, they present a unified ecology that dispels the categorization of the field into the separate subdisciplines of population, community, and ecosystem ecology. Energetic Food Webs is suitable for both graduate level students and professional researchers in the general field of ecology. It will be of particular relevance and use to those working in the specific areas of food webs, species dynamics, material and energy cycling, as well as community and ecosystem ecology.
Prairie dogs, vultures, grasshoppers, goldfinches, pocket gophers, and bison are some of the many animals that make up a grassland food web. But do you know how the many types of grasses in a grassland benefit these animals? Or how earthworms and other decomposers play an important role in the food web? See grassland food webs in action in this fascinating book.
Department of Ecology and Evolutionary Biology Mercedes Pascual,Mercedes Pascual,Jennifer A. Dunne
Author: Department of Ecology and Evolutionary Biology Mercedes Pascual,Mercedes Pascual,Jennifer A. Dunne
Publisher: Oxford University Press
Food webs are one of the most useful, and challenging, objects of study in ecology. These networks of predator-prey interactions, conjured in Darwin's image of a "tangled bank," provide a paradigmatic example of complex adaptive systems. This book is based on a February 2004 Santa Fe Institute workshop. Its authors treat the ecology of predator-prey interactions, food web theory, structure and dynamics. The book explores the boundaries of what is known of the relationship between structure and dynamics in ecological networks and will define directions for future developments in this field.
Food webs hold a central place in ecology. They describe which organisms feed on which others in natural habitats. This book describes recently discovered empirical regularities in real food webs: it proposes a novel theory unifying many of these regularities, as well as extensive empirical data. After a general introduction, reviewing the empirical and theoretical discoveries about food webs, the second portion of the book shows that community food webs obey several striking phenomenological regularities. Some of these unify, regardless of habitat. Others differentiate, showing that habitat significantly influences structure. The third portion of the book presents a theoretical analysis of some of the unifying empirical regularities. The fourth portion of the book presents 13 community food webs. Collected from scattered sources and carefully edited, they are the empirical basis for the results in the volume. The largest available set of data on community food webs provides a valuable foundation for future studies of community food webs. The book is intended for graduate students, teachers and researchers primarily in ecology. The theoretical portions of the book provide materials useful to teachers of applied combinatorics, in particular, random graphs. Researchers in random graphs will find here unsolved mathematical problems.
Frogs, minnows, snails, ducks, catfish, and muskrats are a few of the animals that make up a lake and pond food web. But do you know why mosquitoes, mold, water lilies, and bacteria are important too? Or how humans can change the health of a lake or a pond? See lake and pond food webs in action in this fascinating book.
What is the minimum dimension of a niche space necessary to represent the overlaps among observed niches? This book presents a new technique for obtaining a partial answer to this elementary question about niche space. The author bases his technique on a relation between the combinatorial structure of food webs and the mathematical theory of interval graphs. Professor Cohen collects more than thirty food webs from the ecological literature and analyzes their statistical and combinatorial properties in detail. As a result, he is able to generalize: within habitats of a certain limited physical and temporal heterogeneity, the overlaps among niches, along their trophic (feeding) dimensions, can be represented in a one-dimensional niche space far more often than would be expected by chance alone and perhaps always. This compatibility has not previously been noticed. It indicates that real food webs fall in a small subset of the mathematically possible food webs. Professor Cohen discusses other apparently new features of real food webs, including the constant ratio of the number of kinds of prey to the number of kinds of predators in food webs that describe a community. In conclusion he discusses possible extensions and limitations of his results and suggests directions for future research.
It is a pleasure and a distinct honour for me to greet the participants, guests and ob servers of this Fourth International Symposium on Antarctic Biology which has adopted nutrient cycles and food webs as its central theme. On behalf of the Scientific Committee on Antarctic Research (SCAR) and other bodies of the International Council of Scientific Unions (ICSU), I bid you welcome. SCAR is pleased to acknowledge the role of the co-sponsors for this Symposium which include the Scientific Committee on Oceanic Research (SCOR), the Interna tional Association of Biological Oceanography (IABO), and the International Union of Biological Sciences (IUBS). In addition, SCAR and its co-sponsors wish to acknowledge the financial support of the Council for Scientific and Industrial Re search (CSIR) and the Department of Transport (DOT) of the South African govern ment. Nor should we forget to acknowledge also the role of the South African Scientific Committee on Antarctic Research (SASCAR) and one of its leaders and Vice President of SCAR, Mr. Jan de Wit, in arranging this charming venue for this Symposium.