Ignorant seed predators and factors affecting the seed survival of a tropical palm

BREWER , STEVEN W. and WEBB, MOLLY A. H. (2001) Ignorant seed predators and factors affecting the seed survival of a tropical palm. Oikos. pp. 32-41. ISSN 0030-1299

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    Abstract

    scatter hoarding. This study system used two permanent plots in examining the interaction between small rodents and the seeds of the palm Astrocaryum mexicanum. We tested how experimental burial, and fruiting status of the parent, distance to the parent, seed size, and microsite characteristics affect the survival of these seeds. Up to 34% of the buried seeds that were exposed only to ignorant rodent foragers (individuals not responsible for burial) survived. In comparison, less than 1% of seeds buried by scatter hoarding rodents survived in previous studies, a percentage that is comparable to the low survival of unburied seeds in this study (�2%). Although unburied seeds had very low survival, increasing distance and/or seed density positively affected survival of unburied seeds. Distance to parent had no effect on buried seed survival. Buried seed survival was most strongly and significantly determined by the fruiting status of the trees under which they occurred. Seeds experienced significantly greater predation if buried under ‘‘parent’’ trees that fruited during the experiment. Buried seed survival was also negatively affected by germination, as germination may signal the presence of a seed to foraging rodents. There was some indication of a positive effect of tree density on seed survival between the two plots, whereas differences in rodent abundance appear to have no effect on seed survival. Seed size and microsite characteristics had no significant effect on buried seed survival, likely due to the greater proportional effects of other factors and the longevity of A. mexicanum seeds. The results of this study were used to generate a hypothetical causal network showing how comparatively low recovery of buried seeds by ignorant foragers – combined with processes determining the removal of scatter hoarding foragers from their scattered seed caches – may affect seedling recruitment in A. mexicanum.

    Item Type: Peer-reviewed Journal Article
    Related URLs:
      Publisher: Nordic Ecological Society
      Subjects: (A) Biodiversity > (AH) Plants
      (Z) Other or Unspecified
      Publication Sources: (3) Other Source > (3C) Other Universities
      Date Deposited: 14 Aug 2015 10:18
      Last Modified: 14 Aug 2015 10:18
      URI: http://eprints.uberibz.org/id/eprint/1503

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