From Populations to Ecosystems: Theoretical Foundations for a New Ecological Synthesis

By Michel Loreau | Go to book overview

CHAPTER 4
Food Webs, Interaction Webs, and
Ecosystem Functioning

A food web describes the network of trophic interactions between species, i.e., who eats whom, in an ecosystem. Since trophic interactions are both the vehicle of energy and material transfers and one of the most significant ways in which species interact, they have always lain at the confluence of community and ecosystem ecology. But they have been approached from different perspectives in different traditions. The energetic view articulated by Lindeman (1942) and developed by ecosystem ecology during the following decades views food webs as networks of pathways for the flow of energy in ecosystems, from its capture by autotrophs in the process of photosynthesis to its ultimate dissipation by heterotrophic respiration. A different approach, rooted in community ecology, was initiated by Elton (1927) and developed by May (1973), Pimm (1982), and many others. This approach focuses on the dynamical constraints that arise from species interactions and emphasizes the fact that too much interaction (whether in the form of a large number of species, a large connectance among these species, or a high mean interaction strength) destabilizes complex ecological systems, including food webs. Food webs have also been studied from a topological perspective: the pattern of trophic interactions in a food web is nonrandomly related to species traits, in particular, body size, which led to the development of size-based models of food-web structure such as the cascade and niche models (Cohen et al. 1990; Williams and Martinez 2000). Perhaps the approach that lies most closely to the interface between community and ecosystem ecology is that based on the trophic cascade concept (Carpenter et al. 1985). Hairston et al. (1960) hypothesized that carnivores control herbivores, thereby releasing plants from control by herbivores, in most ecosystems. This simple idea led to a flurry of studies on the community- or ecosystem-level consequences (though mostly the biomass of the various trophic levels) of the top-down control exerted by higher trophic levels on lower trophic levels.

-79-

Notes for this page

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items

Items saved from this book

This book has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this book

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this page

Cited page

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited page

Bookmark this page
From Populations to Ecosystems: Theoretical Foundations for a New Ecological Synthesis
Table of contents

Table of contents

Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this book

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Full screen
/ 300

matching results for page

Cited passage

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited passage

Thanks for trying Questia!

Please continue trying out our research tools, but please note, full functionality is available only to our active members.

Your work will be lost once you leave this Web page.

For full access in an ad-free environment, sign up now for a FREE, 1-day trial.

Already a member? Log in now.