Unravelling the food web: dietary analysis in modern ecology
Calver, M.C. and Porter, B.D. (1986) Unravelling the food web: dietary analysis in modern ecology. Journal of Biological Education, 20 (1). pp. 42-46.
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Feeding behaviour has a central place in the layperson’s concept of ecology, and this is emphasized in the ecology chapters of biology texts. There are diagrams of food chains, food webs, and trophic pyramids and detailed discussions of their significance. This central view of food selection is proper, because it is an important ecosystem process. By their choice of food animals influence the rate of circulation of important nutrients through ecosystems (Ellis et al., 1976), and the dynamics of food selection underlie such important concepts as the theory of the niche (Colwell and Futuyma, 1971), optimal foraging (Pyke, 1984), and food web structure and community stability (Pimm, 1982). However, students are seldom introduced to the methodology of diet analysis as food webs are usually presented as established fact. Consequently, they may never realize that ecologists need rigorous and calibrated methodologies as much as their colleagues in physiology or biochemistry, or that ecological research has its special ethical problems. Also, teachers lose an opportuniy to have students think critically about analysis and experimental design and to encourage them in the intelligent inquiry that is an objective of many biology curricula. The omission is striking in both the BSCS High School Biology (Green Version) and the AAS Web of Life, textbooks with an ecological emphasis and used in the USA and Australia respectively. The Nuffield Biology materials (Wood-Robinson, 1975) consider more methodological detail, but this can still be enlarged upon.
This paper outlines the dietary analysis techniques available to modern ecologists, and explains their potential and limitations. Some suggestions are made for practical exercises that could be done in the laboratory, and for paperwork that could be used for problem solving and discussion in class.
|Publication Type:||Journal Article|
|Murdoch Affiliation:||School of Environmental and Life Sciences|
|Publisher:||Institute of Biology|
|Copyright:||(c) Institute of Biology. Paper reproduced here in accordance with the copyright policy of the publisher.|
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