Competition and stoichiometry: Coexistence of two predators on one prey

Irakli Loladze, Yang Kuang, James Elser, William F. Fagan

Research output: Contribution to journalArticle

96 Scopus citations

Abstract

The competitive exclusion principle (CEP) states that no equilibrium is possible if n species exploit fewer than n resources. This principle does not appear to hold in nature, where high biodiversity is commonly observed, even in seemingly homogenous habitats. Although various mechanisms, such as spatial heterogeneity or chaotic fluctuations, have been proposed to explain this coexistence, none of them invalidates this principle. Here we evaluate whether principles of ecological stoichiometry can contribute to the stable maintenance of biodiverse communities. Stoichiometric analysis recognizes that each organism is a mixture of multiple chemical elements such as carbon (C), nitrogen (N), and phosphorus (P) that are present in various proportions in organisms. We incorporate these principles into a standard predator-prey model to analyze competition between two predators on one autotrophic prey. The model tracks two essential elements, C and P, in each species. We show that a stable equilibrium is possible with two predators on this single prey. At this equilibrium both predators can be limited by the P content of the prey. The analysis suggests that chemical heterogeneity within and among species provides new mechanisms that can support species coexistence and that may be important in maintaining biodiversity.

Original languageEnglish (US)
Pages (from-to)1-15
Number of pages15
JournalTheoretical Population Biology
Volume65
Issue number1
DOIs
StatePublished - Feb 2004

Keywords

  • C:P ratio
  • Competition
  • Consumer-resource
  • Food quality
  • Stoichiometry

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

Fingerprint Dive into the research topics of 'Competition and stoichiometry: Coexistence of two predators on one prey'. Together they form a unique fingerprint.

  • Cite this