Department of Biology, California State University Dominguez Hills, Carson, CA, USA.
Biol Lett. 2010 Aug 23;6(4):490-3. doi: 10.1098/rsbl.2010.0103. Epub 2010 Mar 3.
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.
在自然界中，通常可以观察到物种丰富度和生产力之间呈正相关关系，但原因仍存在争议。一种机制，即“更多个体假说”（MIH），预测丰富度随密度单调增加，这是资源通量的函数。为了验证 MIH，我们在热带雨林落叶蚂蚁群落中操纵资源丰度，并测量了丰富度和密度的响应。与 MIH 的预期相反，丰富度与密度之间的单峰关系最接近对照和干扰（资源去除）处理。与对照相比，资源添加导致丰富度相对于密度单调增加，这种模式与对照相反。在干扰处理中，丰富度大于对照，与 MIH 的预期相反。虽然蚂蚁多样性与净初级生产力或温度之间的大规模相关性与 MIH 相符，但该假说的关键要素并未得到支持。
