The body size dependence of trophic cascades

John P DeLong, Benjamin Gilbert, Jonathan B Shurin, Van M Savage, Brandon T Barton, Christopher F Clements, Anthony I Dell, Hamish S Greig, Christopher D G Harley, Pavel Kratina, Kevin S McCann, Tyler D Tunney, David A Vasseur, Mary I O'Connor

Research output: Contribution to journalArticle (Academic Journal)peer-review

Abstract

Trophic cascades are indirect positive effects of predators on resources via control of intermediate consumers. Larger-bodied predators appear to induce stronger trophic cascades (a greater rebound of resource density toward carrying capacity), but how this happens is unknown because we lack a clear depiction of how the strength of trophic cascades is determined. Using consumer resource models, we first show that the strength of a trophic cascade has an upper limit set by the interaction strength between the basal trophic group and its consumer and that this limit is approached as the interaction strength between the consumer and its predator increases. We then express the strength of a trophic cascade explicitly in terms of predator body size and use two independent parameter sets to calculate how the strength of a trophic cascade depends on predator size. Both parameter sets predict a positive effect of predator size on the strength of a trophic cascade, driven mostly by the body size dependence of the interaction strength between the first two trophic levels. Our results support previous empirical findings and suggest that the loss of larger predators will have greater consequences on trophic control and biomass structure in food webs than the loss of smaller predators.

Original languageEnglish
Pages (from-to)354-66
Number of pages13
JournalAmerican Naturalist
Volume185
Issue number3
DOIs
Publication statusPublished - Mar 2015

Keywords

  • Animals
  • Body Size
  • Conservation of Natural Resources
  • Eukaryota
  • Food Chain
  • Models, Theoretical
  • Predatory Behavior/physiology

Fingerprint Dive into the research topics of 'The body size dependence of trophic cascades'. Together they form a unique fingerprint.

Cite this