THE ZOOLOGICAL BULLETIN OF THE DIVISION OF ZOOLOGY OF THE PENNSYLVANIA DEPT OF AGRICULTURE

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Zoological Bulletin

Author : Pennsylvania. Dept. of Agriculture. Division of Zoology
ISBN : CORNELL:31924070880392
Genre : Zoology, Economic
File Size : 26.4 MB
Format : PDF
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Category: Zoology, Economic

The Food Web Of A Tropical Rain Forest

Author : Douglas P. Reagan
ISBN : 0226706001
Genre : Science
File Size : 84.20 MB
Format : PDF, Docs
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Destruction of tropical rain forests has increased exponentially in recent years, as have efforts to conserve them. However, information essential to these conservation programs—an understanding of the population dynamics of the community at risk—is often unavailable to the scientists and resource managers who need it most. This volume helps fill the gap by presenting a comprehensive description and analysis of the animal community of the tropical rain forest at El Verde, Puerto Rico. Building on more than a decade of field research, the contributors weave the complex strands of information about the energy flow within the forest—who eats whom—into a powerful tool for understanding community dynamics known as a food web. This systematic approach to organizing the natural histories of the many species at El Verde also reveals basic patterns and processes common to all rain forests, making this book a valuable contribution for anyone concerned with studying and protecting these fragile ecosystems.
Category: Science

Alien Reptiles And Amphibians

Author : Fred Kraus
ISBN : 9781402089466
Genre : Nature
File Size : 49.8 MB
Format : PDF, Mobi
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Transportation of species to areas outside their native ranges has been a feature of human culture for millennia. During this time such activities have largely been viewed as beneficial or inconsequential. However, it has become increasingly clear that human-caused introductions of alien biota are an ecological disruption whose consequences rival those of better-known insults like chemical pollution, habitat loss, and climate change. Indeed, the irreversible nature of most alien-species int- ductions makes them less prone to correction than many other ecological problems. Current reshuffling of species ranges is so great that the present era has been referred to by some as the “Homogocene” in an effort to reflect the unique mag- tude of the changes being made. These alien interlopers often cause considerable ecological and economic d- age where introduced. Species extinctions, food-web disruptions, community alte- tions, ecosystem conversion, changes in nutrient cycling, fisheries collapse, watershed degradation, agricultural loss, building damage, and disease epidemics are among the destructive – and frequently unpredictable – ecological and economic effects that invasive alien species can inflict. The magnitude of these damages c- tinues to grow, with virtually all environments heavily used by humans now do- nated by alien species and many “natural” areas becoming increasingly prone to alien invasion as well. Attention to this problem has increased in the past decade or so, and efforts to prevent or limit further harm are gaining wider scientific and political acceptance.
Category: Nature

The Zoological Quarterly Bulletin

Author : Pennsylvania. Dept. of Agriculture. Division of Zoology
ISBN : UOM:39015069876566
Genre : Zoology
File Size : 63.33 MB
Format : PDF, Mobi
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Category: Zoology

Frogs Of The United States And Canada 2 Vol Set

Author : C. Kenneth Dodd
ISBN : 9781421406336
Genre : Nature
File Size : 44.87 MB
Format : PDF, ePub
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With many frog populations declining or disappearing and developmental malformations and disease afflicting others, scientists, conservationists, and concerned citizens need up-to-date, accurate information. Frogs of the United States and Canada is a comprehensive resource for those trying to protect amphibians as well as for researchers and wildlife managers who study biodiversity. From acrobatic tree frogs to terrestrial toads, C. Kenneth Dodd Jr. offers an unparalleled synthesis of the biology, behavior, and conservation of frogs in North America. This two-volume, fully referenced resource provides color photographs and range maps for 106 native and nonindigenous species and includes detailed information on- past and present distribution- life history and demography - reproduction and diet- landscape ecology and evolution- - diseases, parasites, and threats from toxic substances- conservation and management
Category: Nature