Terrence P. McGlynn1,*, Michael D. Weiser2 and Robert R. Dunn2,3
-Author Affiliations
1Department of Biology, California State University Dominguez Hills, Carson, CA, USA
2Department of Biology, North Carolina State University, Raleigh, NC, USA
3Keck Center for Behavioral Biology, North Carolina State University,Raleigh, NC, USA
*Author for correspondence (terry.mcglynn@gmail.com).
Abstract
A positive relationship between species richness and productivity is often observed in nature, but the causes remain contentious. One mechanism, the ‘more individuals hypothesis’ (MIH), predicts richness increases monotonically with density, as a function of resource flux. To test the MIH, we manipulated resource abundance in a community of tropical rainforest litter ants and measured richness and density responses. A unimodal relationship between richness and density most closely fitted the control and disturbance (resource removal) treatments in contrast to expectations of the MIH. Resource addition resulted in a monotonic increase in richness relative to density, a shift from the pattern in the control. In the disturbance treatment, richness was greater than in the control, opposite to expectations of the MIH. While large-scale correlations between ant diversity and net primary productivity or temperature are reconcilable with the MIH, key elements of the hypothesis are not supported.
ants competition diversity leaf litter
Footnotes
Received February 1, 2010.
Accepted February 12, 2010.
© 2010 The Royal Society
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