The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
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Because plants can photosynthesize, they form the base of food chains in most ecosystems. During the past five hundred million years, vertebrates have evolved many methods of extracting energy from plants, which can have positive or negative impacts on individual plants and their populations.
In contrast, many vertebrates interact negatively with plants as herbivores and seed-eaters. Herbivory, which involves the consumption of leaves, roots, and stems, can reduce plant growth rates and seed production if it does not kill plants outright. Seed predation, in which animals destroy plant embryos, is a specialized form of herbivory. Herbivory is much more common in mammals than in birds. Ptarmigan and grouse are avian herbivores; rodents, rabbits, cows and their relatives, and horses and their relatives are mammalian herbivores. Seed-eating is much more common than herbivory in birds. (Examples include parrots, pigeons, finches, and sparrows.) Major mammalian seed-eaters are squirrels, rats, and mice. Whereas vertebrate mutualists are beneficial for certain economically important plants, vertebrate herbivores and seed-eaters can cause millions of dollars of damage annually to many economically important crops. Humans, too, are vertebrates, and the interactions of plants and humans, especially through agriculture, has had profound consequences for each.
Coevolution; Pollination Biology.
Howe, H. F., and L. C. Westley. Ecological Relationships of Plants and Animals. New York: Oxford University Press, 1988.