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Three-way coexistence in obligate mutualist-exploiter interactions: the potential role of competition.

Publication ,  Journal Article
Morris, WF; Bronstein, JL; Wilson, WG
Published in: The American naturalist
June 2003

Many mutualisms host "exploiter" species that consume the benefits provided by one or both mutualists without reciprocating. Exploiters have been widely assumed to destabilize mutualisms, yet they are common. We develop models to explore conditions for local coexistence of obligate plant/pollinating seed parasite mutualisms and nonpollinating exploiters. As the larvae of both pollinators and (at a later time) exploiters consume seeds, we examine the importance of intraspecific and (asymmetric) interspecific competition among and between pollinators and exploiters for achieving three-way coexistence. With weak intra- and interspecific competition, exploiters can invade the stable mutualism and coexist with the mutualists (either stably or with oscillations), provided the exploiters' intrinsic birthrate (b(E)) slightly exceeds that of the pollinators. At higher b(E), all three species go locally extinct. When facing strong interspecific competition, exploiters cannot invade and coexist with the mutualists if intraspecific competition in pollinators and exploiters is weak. However, strong intraspecific competition in pollinators and exploiters facilitates exploiter invasion and coexistence and greatly expands the range of b(E) over which stable coexistence occurs. Our results suggest that mutualist/exploiter coexistence may be more easily achieved than previously thought, thus highlighting the need for a better understanding of competition among and between mutualists and exploiters.

Duke Scholars

Published In

The American naturalist

DOI

EISSN

1537-5323

ISSN

0003-0147

Publication Date

June 2003

Volume

161

Issue

6

Start / End Page

860 / 875

Related Subject Headings

  • Yucca
  • Seeds
  • Population Dynamics
  • Pollen
  • Models, Biological
  • Larva
  • Insecta
  • Host-Parasite Interactions
  • Ecology
  • Biological Evolution
 

Citation

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Chicago
ICMJE
MLA
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Morris, W. F., Bronstein, J. L., & Wilson, W. G. (2003). Three-way coexistence in obligate mutualist-exploiter interactions: the potential role of competition. The American Naturalist, 161(6), 860–875. https://doi.org/10.1086/375175
Morris, William F., Judith L. Bronstein, and William G. Wilson. “Three-way coexistence in obligate mutualist-exploiter interactions: the potential role of competition.The American Naturalist 161, no. 6 (June 2003): 860–75. https://doi.org/10.1086/375175.
Morris WF, Bronstein JL, Wilson WG. Three-way coexistence in obligate mutualist-exploiter interactions: the potential role of competition. The American naturalist. 2003 Jun;161(6):860–75.
Morris, William F., et al. “Three-way coexistence in obligate mutualist-exploiter interactions: the potential role of competition.The American Naturalist, vol. 161, no. 6, June 2003, pp. 860–75. Epmc, doi:10.1086/375175.
Morris WF, Bronstein JL, Wilson WG. Three-way coexistence in obligate mutualist-exploiter interactions: the potential role of competition. The American naturalist. 2003 Jun;161(6):860–875.
Journal cover image

Published In

The American naturalist

DOI

EISSN

1537-5323

ISSN

0003-0147

Publication Date

June 2003

Volume

161

Issue

6

Start / End Page

860 / 875

Related Subject Headings

  • Yucca
  • Seeds
  • Population Dynamics
  • Pollen
  • Models, Biological
  • Larva
  • Insecta
  • Host-Parasite Interactions
  • Ecology
  • Biological Evolution