Field experiments show contradictory short- and long-term myrmecochorous plant impacts on seed-dispersing ants

  • Authors: Warren, Robert J.; Elliott, Katherine J.; Giladi, Itamar; King, Joshua R.; Bradford, Mark A.
  • Publication Year: 2018
  • Publication Series: Scientific Journal (JRNL)
  • Source: Ecological Entomology
  • DOI: 10.1111/een.12666

Abstract

  1. Some interactions previously describe as mutualistic were revealed to be commensal or parasitic in subsequent investigations. Ant-mediated seed dispersal has been describe as a mutualism for more than a century; however, recent research suggests that it may be commensal or parasitic. Plants demonstrably benefit from ant-mediated seed dispersal, although there is little evidence available to demonstrate that the interaction benefits long-term ant fitness.
  2. Field experiments were conducted in temperate North America focused on a key seed-dispersing ant. All herbaceous plants were removed from a forest understorey for 13 years, and supplemented ant colonies with large elaiosome-bearing seeds aiming to examine potential long-and short-term myrmecochorous plant benefits for the ants.
  3. If elaiosome-bearing seeds benefit ants, suggesting a mutualistic relationship, it is expected that there would be greater worker and/or alate abundance and greater fat reserves (colony lipid content) with seed supplementation (short-term) and in areas with high understorey herb abundance.
  4. Short-term seed supplementation of ant colonies did not result in an increase with respect to numbers or fat stores, although it did prompt the production of colony sexuals, which is a potential fitness benefit. In the long term, however, there was no positive effect on the ants and, instead, there were negative effects because the removal of elaiosome-bearing plants corresponded with greater colony health.
  5. The data obtained in the present study suggest that the ant-plant interaction ranged from occasionally beneficial to neutral to overall negative for the ant partner. Such results did not support considering the interaction as a mutualism. Collectively, the data suggest the need to reconsider the nature of the relationship between these ants and plants.

  • Citation: Warren, Robert J.; Elliott, Katherine J.; Giladi, Itamar; King, Joshua R.; Bradford, Mark A. 2018. Field experiments show contradictory short- and long-term myrmecochorous plant impacts on seed-dispersing ants. Ecological Entomology. 21: 411-. https://doi.org/10.1111/een.12666.
  • Keywords: Animal-plant interactions, Aphaenogaster commensalism, dispersal herbaceous mutualism species interactions woodlawn
  • Posted Date: August 2, 2018
  • Modified Date: August 20, 2018
  • Print Publications Are No Longer Available

    In an ongoing effort to be fiscally responsible, the Southern Research Station (SRS) will no longer produce and distribute hard copies of our publications. Many SRS publications are available at cost via the Government Printing Office (GPO). Electronic versions of publications may be downloaded, printed, and distributed.

    Publication Notes

    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
    • Our online publications are scanned and captured using Adobe Acrobat. During the capture process some typographical errors may occur. Please contact the SRS webmaster if you notice any errors which make this publication unusable.
    • To view this article, download the latest version of Adobe Acrobat Reader.