Coexistence of Top Predators in Headwater Streams

Coexistence of Top Predators in Headwater Streams PDF Author: David E. Rundio
Publisher:
ISBN:
Category : Cutthroat trout
Languages : en
Pages : 192

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Book Description
The coexistence of multiple predators may have important consequences for the structure and function of communities. Interactions between predators may strongly affect their combined direct and indirect effects on prey populations and lower trophic levels. Predators often have size-structured populations, which may result in intraguild predation characterized by complex trophic and behavioral interactions. Coexistence of multiple predators may strongly depend on antipredator defenses of small size classes that reduce their vulnerability to predation. In Pacific Northwest forested ecosystems, Pacific giant salamanders (Dicamptodon tenebrosus) and coastal cutthroat trout (Oncorhynchus clarki clarki) are the top predators in many perennial headwater streams. Dicamptodon and cutthroat have size-structured populations with roughly corresponding size classes, and interactions between these species appear consistent with intraguild predation. My research objective was to determine the mechanisms contributing to the coexistence of Dicamptodon larvae with cutthroat trout in headwater streams, and the effects of this coexistence on factors related to Dicamptodon fitness. First, I tested for two general types of antipredator defenses of young-of-year Dicamptodon larvae against trout. Larvae were palatable to trout during initial and repeated offerings, which suggests that they may survive few encounters with trout. However, larvae increased refuge use in response to non-visual, chemical cues from trout, which likely reduces the probability of encounters with trout and contributes to their coexistence. Second, I measured the effects of cutthroat trout on Dicamptodon fitness parameters in a field experiment. Dicamptodon survival, growth, and behavior (activity level) did not differ between trout-present and trout-absent pools, although these results were compromised by unexplained gains or losses of larvae from most pools. Antipredator behaviors may promote coexistence of Dicamptodon and cutthroat trout, and may contribute to a complex series of behavioral and trophic interactions affecting lower trophic levels within headwater stream communities.

Coexistence of Top Predators in Headwater Streams

Coexistence of Top Predators in Headwater Streams PDF Author: David E. Rundio
Publisher:
ISBN:
Category : Cutthroat trout
Languages : en
Pages : 192

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Book Description
The coexistence of multiple predators may have important consequences for the structure and function of communities. Interactions between predators may strongly affect their combined direct and indirect effects on prey populations and lower trophic levels. Predators often have size-structured populations, which may result in intraguild predation characterized by complex trophic and behavioral interactions. Coexistence of multiple predators may strongly depend on antipredator defenses of small size classes that reduce their vulnerability to predation. In Pacific Northwest forested ecosystems, Pacific giant salamanders (Dicamptodon tenebrosus) and coastal cutthroat trout (Oncorhynchus clarki clarki) are the top predators in many perennial headwater streams. Dicamptodon and cutthroat have size-structured populations with roughly corresponding size classes, and interactions between these species appear consistent with intraguild predation. My research objective was to determine the mechanisms contributing to the coexistence of Dicamptodon larvae with cutthroat trout in headwater streams, and the effects of this coexistence on factors related to Dicamptodon fitness. First, I tested for two general types of antipredator defenses of young-of-year Dicamptodon larvae against trout. Larvae were palatable to trout during initial and repeated offerings, which suggests that they may survive few encounters with trout. However, larvae increased refuge use in response to non-visual, chemical cues from trout, which likely reduces the probability of encounters with trout and contributes to their coexistence. Second, I measured the effects of cutthroat trout on Dicamptodon fitness parameters in a field experiment. Dicamptodon survival, growth, and behavior (activity level) did not differ between trout-present and trout-absent pools, although these results were compromised by unexplained gains or losses of larvae from most pools. Antipredator behaviors may promote coexistence of Dicamptodon and cutthroat trout, and may contribute to a complex series of behavioral and trophic interactions affecting lower trophic levels within headwater stream communities.

Ecological Interactions Among Predators in Headwater Stream Communities

Ecological Interactions Among Predators in Headwater Stream Communities PDF Author: William John Resetarits
Publisher:
ISBN:
Category : Predation (Biology)
Languages : en
Pages : 294

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Trophic Cascades

Trophic Cascades PDF Author: John Terborgh
Publisher: Island Press
ISBN: 1597268194
Category : Science
Languages : en
Pages : 487

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Book Description
Trophic cascades—the top-down regulation of ecosystems by predators—are an essential aspect of ecosystem function and well-being. Trophic cascades are often drastically disrupted by human interventions—for example, when wolves and cougars are removed, allowing deer and beaver to become destructive—yet have only recently begun to be considered in the development of conservation and management strategies. Trophic Cascades is the first comprehensive presentation of the science on this subject. It brings together some of the world’s leading scientists and researchers to explain the importance of large animals in regulating ecosystems, and to relate that scientific knowledge to practical conservation. Chapters examine trophic cascades across the world’s major biomes, including intertidal habitats, coastal oceans, lakes, nearshore ecosystems, open oceans, tropical forests, boreal and temperate ecosystems, low arctic scrubland, savannas, and islands. Additional chapters consider aboveground/belowground linkages, predation and ecosystem processes, consumer control by megafauna and fire, and alternative states in ecosystems. An introductory chapter offers a concise overview of trophic cascades, while concluding chapters consider theoretical perspectives and comparative issues. Trophic Cascades provides a scientific basis and justification for the idea that large predators and top-down forcing must be considered in conservation strategies, alongside factors such as habitat preservation and invasive species. It is a groundbreaking work for scientists and managers involved with biodiversity conservation and protection.

Novel Trophic Cascades

Novel Trophic Cascades PDF Author: Arian D. Wallach
Publisher:
ISBN:
Category : Introduced organisms
Languages : en
Pages : 8

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Book Description
Efforts to control introduced species are often risky, expensive and ineffective. Trophic cascades theory elucidates why some introduced species cause harm. Apex predators limit population irruptions of both native and introduced species. ?Restoring apex predators can help promote native?non-native coexistence. Novel assemblages of native and introduced species characterize a growing proportion of ecosystems worldwide. Some introduced species have contributed to extinctions, even extinction waves, spurring widespread efforts to eradicate or control them. We propose that trophic cascade theory offers insights into why introduced species sometimes become harmful, but in other cases stably coexist with natives and offer net benefits. Large predators commonly limit populations of potentially irruptive prey and mesopredators, both native and introduced. This top-down force influences a wide range of ecosystem processes that often enhance biodiversity. We argue that many species, regardless of their origin or priors, are allies for the retention and restoration of biodiversity in top-down regulated ecosystems. -- Highlights.

The Zoological Record

The Zoological Record PDF Author:
Publisher:
ISBN:
Category : Animals
Languages : en
Pages : 1240

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Stream Ecology

Stream Ecology PDF Author: J. David Allan
Publisher: Springer Nature
ISBN: 3030612864
Category : Science
Languages : en
Pages : 485

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Book Description
Stream Ecology: Structure and Function of Running Waters is designed to serve as a textbook for advanced undergraduate and graduate students, and as a reference source for specialists in stream ecology and related fields. This Third Edition is thoroughly updated and expanded to incorporate significant advances in our understanding of environmental factors, biological interactions, and ecosystem processes, and how these vary with hydrological, geomorphological, and landscape setting. The broad diversity of running waters – from torrential mountain brooks, to large, lowland rivers, to great river systems whose basins occupy sub-continents – makes river ecosystems appear overwhelming complex. A central theme of this book is that although the settings are often unique, the processes at work in running waters are general and increasingly well understood. Even as our scientific understanding of stream ecosystems rapidly advances, the pressures arising from diverse human activities continue to threaten the health of rivers worldwide. This book presents vital new findings concerning human impacts, and the advances in pollution control, flow management, restoration, and conservation planning that point to practical solutions. Reviews of the first edition: ".. an unusually lucid and judicious reassessment of the state of stream ecology" Science Magazine "..provides an excellent introduction to the area for advanced undergraduates and graduate students..." Limnology & Oceanography "... a valuable reference for all those interested in the ecology of running waters." Transactions of the American Fisheries Society Reviews of the second edition: "Overall, a must for the field centre and a good starter text in stream ecology." (TEN News, October, 2007) "Highly recommended. Upper-division undergraduates through faculty." (P. R. Pinet, CHOICE, Vol. 45 (7), 2008) "... a very good, fluidly readable book which contains the latest key scientific knowledge of the ecology of running waters." (Daniel Graeber, International Review of Hydrobiology, Vol. 94 (2), 2009)

2002 Science Accomplishments of the Pacific Northwest Research Station

2002 Science Accomplishments of the Pacific Northwest Research Station PDF Author:
Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 76

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Aquatic Food Webs

Aquatic Food Webs PDF Author: Andrea Belgrano
Publisher: Oxford University Press
ISBN: 0191524069
Category : Science
Languages : en
Pages : 262

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Book Description
This volume provides a current synthesis of theoretical and empirical food web research. Whether they are binary systems or weighted networks, food webs are of particular interest to ecologists in providing a macroscopic view of ecosystems. They describe interactions between species and their environment, and subsequent advances in the understanding of their structure, function, and dynamics are of vital importance to ecosystem management and conservation. Aquatic Food Webs provides a synthesis of the current issues in food web theory and its applications, covering issues of structure, function, scaling, complexity, and stability in the contexts of conservation, fisheries, and climate. Although the focus of this volume is upon aquatic food webs (where many of the recent advances have been made), any ecologist with an interest in food web theory and its applications will find the issues addressed in this book of value and use. This advanced textbook is suitable for graduate level students as well as professional researchers in community, ecosystem, and theoretical ecology, in aquatic ecology, and in conservation biology.

Issues in Global Environment—Freshwater and Marine Environments: 2013 Edition

Issues in Global Environment—Freshwater and Marine Environments: 2013 Edition PDF Author:
Publisher: ScholarlyEditions
ISBN: 1490109668
Category : Science
Languages : en
Pages : 1141

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Book Description
Issues in Global Environment—Freshwater and Marine Environments: 2013 Edition is a ScholarlyEditions™ book that delivers timely, authoritative, and comprehensive information about Continental Shelf Research. The editors have built Issues in Global Environment—Freshwater and Marine Environments: 2013 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Continental Shelf Research in this book to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Global Environment—Freshwater and Marine Environments: 2013 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

The Influence of Cannibalism and Size Structure on the Dynamics of Aquatic Communities

The Influence of Cannibalism and Size Structure on the Dynamics of Aquatic Communities PDF Author: Volker H. W. Rudolf
Publisher:
ISBN:
Category :
Languages : en
Pages : 502

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Book Description