Predation and Food Webs - Freshwater Ecology: Concepts and Environmental Applications - page 390

19 Predation
and Food
Webs
Herbivory
Detritivory and Omnivory
Adaptation to Predation Pressure
Adaptations of Predators
Nonlethal Effects of Predation
Trophic Levels, Food Webs, and Food Chains
The Trophic Cascade
Theoretical Community Ecology and Aquatic Food Webs
Summary
Questions for Thought
In this chapter I first consider herbivory, detritivory, omnivory, and
predation on animals. Second, adaptations in response to being prey or
predator are discussed. Third, food webs and their dynamics are ap-
proached. A food web is the network of predator-prey interactions that
occurs in an ecological community. Food chains are the most simplistic
view of food webs, in which only trophic levels (e.g., producers and con-
sumers) are considered. Food webs and predation in lakes and streams
have received a tremendous amount of attention. It has been suggested that
“food webs are a central, if not the central, idea in ecology” (Wilbur,
1997). Though not all ecologists agree with this statement, most recognize
that food webs are an essential aspect of ecological interactions and must
be considered with other factors, such as abiotic effects and competition
(Wilbur, 1987).
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