Habitat Complexity and the Influence on Predators and Prey, and Their Interactions PDF Download

Author: Anders Nilsson
Publisher:
ISBN:
Category :
Languages : en
Pages : 27

View

Book Description

Author: S.S. Bell
Publisher: Springer Science & Business Media
ISBN: 9401130760
Category : Science
Languages : en
Pages : 451

View

Book Description
We conceived the idea for this book after teaching a graduate seminar on 'Habitat Complexity' at The University of South Florida. Discussions during the seminar led us to conclude that similar goals were to be found in studies of the topic that spanned the breadth of ecological research. Yet, the exact meaning of 'habitat structure', and the way in which it was measured, seemed to differ widely among subdisciplines. Our own research, which involves several sorts of ecology, convinced us that the differences among subdisciplines were indeed real ones, and that they did inhibit communica tion. We decided that interchange of ideas among researchers working in marine ecology, plant-animal interactions, physiological ecology, and other more-or-less independent fields would be worthwhile, in that it might lead to useful generalizations about 'habitat structure'. To foster this interchange of ideas. we organized a symposium to attract researchers working with a wide variety of organisms living in many habitats, but united in their interest in the topic of 'habitat structure'. The symposium was held at The University of South Florida's Chinsegut Hill Conference Center, in May. 1988. We asked participants to think about 'habitat structure' in new ways; to synthesize important, but fragmented, information; and. perhaps. to consider ways of translating ideas across systems. The chapters contained in this book reflect the participants' attempts to do so. The book is divided into four parts, by major themes that we have found useful categorizations.

Author: Pedro Barbosa
Publisher: Oxford University Press
ISBN: 0195171209
Category : Science
Languages : en
Pages : 413

View

Book Description
This book addresses the fundamental issues of predator-prey interactions, with an emphasis on predation among arthropods, which have been better studied, and for which the database is more extensive than for the large and rare vertebrate predators. The book should appeal to ecologists interested in the broad issue of predation effects on communities.

Author: Pedro Barbosa
Publisher: Oxford University Press
ISBN: 9780195171204
Category : Nature
Languages : en
Pages : 424

View

Book Description
This book addresses the fundamental issues of predator-prey interactions, with an emphasis on predation among arthropods, which have been better studied, and for which the database is more extensive than for the large and rare vertebrate predators. The book should appeal to ecologists interested in the broad issue of predation effects on communities.

Author: Nicolas Christian Ory
Publisher:
ISBN:
Category : Shrimps
Languages : en
Pages : 0

View

Book Description

Author: Peter Eklöv
Publisher:
ISBN: 9789171749840
Category :
Languages : en
Pages : 20

View

Book Description

Author: Bo Ebenman
Publisher: Springer Science & Business Media
ISBN: 3642740014
Category : Science
Languages : en
Pages : 288

View

Book Description
At last both ecology and evolution are covered in this study on the dynamics of size-structured populations. How does natural selection shape growth patterns and life cycles of individuals, and hence the size-structure of populations? This book will stimulate biologists to look into some important and interesting biological problems from a new angle of approach, concerning: - life history evolution, - intraspecific competition and niche theory, - structure and dynamics of ecological communities.

Author: John P. DeLong
Publisher: Oxford University Press
ISBN: 019264808X
Category : Science
Languages : en
Pages : 192

View

Book Description
Predator-prey interactions are ubiquitous, govern the flow of energy up trophic levels, and strongly influence the structure of ecological systems. They are typically quantified using the functional response - the relationship between a predator's foraging rate and the availability of food. As such, the functional response is central to how all ecological communities function - since all communities contain foragers - and a principal driver of the abundance, diversity, and dynamics of ecological communities. The functional response also reflects all the behaviors, traits, and strategies that predators use to hunt prey and that prey use to evade predation. It is thus both a clear reflection of past evolution, including predator-prey arms races, and a major force driving the future evolution of both predator and prey. Despite their importance, there have been remarkably few attempts to synthesize or even briefly review functional responses. This novel and accessible book fills this gap, clearly demonstrating their crucial role as the link between individuals, evolution, and community properties, representing a highly-integrated and measurable aspect of ecological function. It provides a clear entry point for students, a refresher for more advanced researchers, and a motivator for future research. Predator Ecology is an advanced textbook suitable for graduate students and researchers in ecology and evolutionary biology seeking a broad, up-to-date, and authoritative coverage of the field. It will also be of relevance and use to mathematical ecologists, wildlife biologists, and anyone interested in predator-prey interactions.

Author:
Publisher:
ISBN:
Category : Electronic books
Languages : en
Pages : 183

View

Book Description
The interactions between predators and their prey are key drivers of structure and functioning in many ecosystems. However, the ability of predators to effectively regulate prey abundance can be strongly modified by the context in which trophic interactions occur. My dissertation explores the effects of five factors which have the potential to mediate trophic interactions on nearshore reefs: prey density, organismal body size, habitat complexity, animal behavior, and fishery harvest. Working on both temperate rocky reefs and tropical coral reefs, I use field- and lab-based experiments as well as a numerical model to better understand the interactions among sea urchins, their finfish and invertebrate predators, and the nearshore reefassociated communities of which they are a part. Chapters 1 and 2 focus on the dynamics between sea urchins, spiny lobsters, and fish predators on the rocky reefs of southern California. Following the extirpation of the archetypal urchin predator, the sea otter (Enhydra lutris), top-down control of urchins in this system by spiny lobsters (Panulirus interruptus) and the labrid fish California sheephead (Semicossyphus pulcher), has been hypothesized, but rarely tested experimentally. Chapter 1 tests for densitydependent mortality of purple (Strongylocentrotus purpuratus) and red (Mesocentrotus franciscanus) urchins due to predation by finfish and lobsters. In laboratory feeding assays, spiny lobsters demonstrate a saturating functional response to urchin prey, whereby urchin proportional mortality is inversely density-dependent. In field experiments on rocky reefs near San Diego, CA, when purple urchins are offered alone, I find evidence of positive density-dependent urchin mortality at low densities, similar to those found within kelp forests. At higher prey densities, analogous to those found within urchin barrens, prey mortality is density-independent. When red and purple urchins are deployed to reefs simultaneously, urchin mortality is density-independent and fish do not aggregate to higher density patches. This shift in predation mortality is likely due to the increased biomass of the alternative red urchin prey rather than the increased structural complexity offered by their large spine canopy. Overall, results from Chapter 1 suggest that topdown control of urchins can occur only under limited circumstances, when predatory fish are abundant and large red urchins are absent. In Chapter 2, I develop a tri-trophic, size-structured numerical model of a southern California rocky reef. The model includes multiple ecological processes that can drive feedbacks across trophic levels leading to alternative stable states, including recruitment facilitation and size-structured predation. I find that fishery harvest for the predator (spiny lobster) and prey (red urchins) interacts to determine the level of ecological resilience exhibited by the system, i.e. the likelihood of shifting between alternative stable states. Specifically, I show that predator harvest can drive the system from a kelp forest to an urchin barren, but that prey harvest determines the likelihood of this shift. Size-structured predation on urchins is the feedback maintaining a given ecosystem state. This model suggests that ecosystem resilience depends on both predator and prey harvest in multi-trophic level harvest scenarios, which are common in marine ecosystems but are rarely accounted for by traditional single-species management. Collectively, my first two chapters demonstrate that predator regulation of urchins can occur only under limited circumstances which strongly depend on both predator and prey body size and species composition. These findings also have significant implications for the dynamics of alternative community states observed on rocky reefs, as harvesting predators and harvesting prey can interact to determine the ecological resilience of these important coastal habitats. In addition to density and organismal body size, habitat complexity can also play a vital role in shaping ecological communities. However, many coral reef ecosystems are shifting to alternative states with reduced structural complexity and altered community assemblages. Smallbodied herbivores, such as sea urchins, are common inhabitants of reefs, and their importance for controlling the distribution and abundance of algae in marine ecosystems is well understood. Less understood is the role of habitat complexity and species identity of foundational species in dictating the abundance of this increasingly-important group of herbivores. In Chapters 3 and 4, I explore the feedbacks between habitat complexity, herbivorous urchins, and their predators on fringing coral reefs of Bocas del Toro, located on the Caribbean coast of Panama. In Chapter 3, I use benthic surveys, tethering, and laboratory experiments to show that the structural complexity and species identity of three corals commonly observed on Caribbean reefs mediate the abundance, behavior, and demographic characteristics of an increasingly important herbivore, the reef urchin Echinometra viridis. Tethered urchins survive better on the more structurally complex coral Agaricia tenuifolia and hydrocoral Millepora alcicornis than on less complex branching Porites species. However, natural densities of urchins on these corals do not follow the same pattern, suggesting that coral identity, independent of complexity, also contributes to habitat associations. In habitat choice experiments, urchins prefer the structurally complex coral A. tenuifolia only when waterborne cues of predators are introduced. Despite minimal differences in the standing stock of algae associated with the different corals, urchins inhabiting Porites colonies have a marginally higher reproductive condition than those collected from the other corals, suggesting a fitness trade off to inhabiting the riskier coral. Understanding the drivers of herbivore habitat associations is vital for predicting the persistence of coral-dominated reefs due to feedbacks between changing coral reef communities (both species identity and habitat complexity) and shifts to algal dominance. In Chapter 4, I explore the potential for non-consumptive effects (NCEs) of predatory spiny lobsters on the grazing and movement behaviors of two urchins (E. viridis and Diadema antillarum) which contribute to Caribbean coral reef resilience. Non-consumptive effects of predators on their prey can be an important influence on ecosystems because predators can suppress the ecological function of far more prey than they can consume. However, herbivore responses to predatory risk cues can differ among species which otherwise could be functionally similar. Cues from a generalist predator, the Caribbean spiny lobster (Panulirus argus), strongly suppress grazing by Diadema but not Echinometra. Conversely, cues produced by simulated predation on conspecific urchins cause reduced grazing by Echinometra but not Diadema. In field tests for NCEs on movement behavior, Echinometra consistently move away from lobsters on coral colonies of a variety of structural complexity levels, but movement rates are reduced in response to lobster cues only when on highly rugose corals. Diadema movement is not affected by the presence of lobsters. The contrasting responses exhibited by these two urchins suggest that herbivore populations and their functional roles may respond in unexpected ways to anthropogenic changes to predator communities and reef structural complexity. Together, these chapters provide evidence of the importance of small-bodied herbivores to Caribbean coral reef resilience through feedbacks between herbivory and habitat complexity and improve our understanding of trophic interactions on degraded contemporary coral reefs.

Author: Kristopher Pitcher
Publisher:
ISBN:
Category : Freshwater ecology
Languages : en
Pages : 0

View

Book Description