The Ecological Effects of Ant-Aphid Mutualism on Plants at a Large Spatial Scale

Abstract

The protective ant-plant interaction has been considered as a model system in studying mutualistic interactions, but we know little about the ecological effects of the mutualism at relatively larger spatial scales. In this study, by excluding an aphid-tending ant species (Lasius fuliginosus) from all host oak trees (Quercus liaotungensis) in 20x20 m plots, we evaluated the effects of ants on herbivory, fruit production and leaf toughness of the host tree. Through a two years study, we found that ants have a significant anti-herbivory effect on the host tree, with no effects on fruit production. At the end of the growing season, leaf toughness for plants without ants increased significantly. This suggests that ants are reliable and effective bodyguards for plants at larger spatial scales. For plants, the possible tradeoff between different defensive strategies at larger scale should be focused in further works.

Keywords

• Ant defense
• ant-plant interaction
• herbivory
• exclusion experiment