Print PageThe ant-aphid mutualism plays a key role in shaping the structure and diversity of the arthropod community on plants. But whether the effects of the mutualism can transmit from the canopy on which the mutualism occurs to the forest floor is unclear. We investigated this issue in a deciduous temperate forest in Beijing, China. At first we surveyed the relationship between the abundance of ant and other arthropods at ten transected lines; second we broke the ant-aphid mutualism by excluding ants from forest canopy at different sized plots, and then monitored the abundance of ants and other arthropods on forest floor at a serial of times by traps.
Results/Conclusions
The field survey showed that the abundances of beetles and ants were negatively correlated, but spiders and other arthropods. In a large scale ant-exclusion experiment (80*60m in the study), the breakdown of ant-aphid mutualism could lead to the reduction of ant abundance on forest floor, associated with the enhancement of beetle abundances. The total abundance of arthropods on forest floor was not impacted by the mutualism; but from the point of the community structure, the abundance of herbivores on forest floor was significantly suppressed by the ant-aphid mutualism rather than predators and omnivores. These results suggest that, aphids are the key factor that shapes the abundance of ants not only on canopy but also on forest floor. The high abundance of ants on forest floor caused by aphids on canopy has significant impacts on the ground arthropod community. Therefore our study confirms that the ecological effects of the ant-aphid mutualism can transmit from the canopy to forest floor.
