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Fine-scale variation of a keystone interaction: aphid-tending ants show stronger anti-herbivory effects on small leaves

Authors Zhang, Shuang; Zhang, Yu-Xin; Ma, Ke-Ming

Journal ARTHROPOD-PLANT INTERACTIONS , JUN 2020,3:14

DOI 10.1007/s11829-020-09754-9

Abstract The ecological effects of the keystone mutualism between sap-feeding insects have been evaluated from the individual to landscape scales, but these effects'' fine-scale variation has not been characterized well. Here, we tested a simple hypothesis that aphid-tending ants'' effect on plant herbivory should be stronger on small leaves, with a dataset that included 15,602 leaves of a widely distributed oak tree (Quercus wutaishansea). The results showed that, consistent with our prediction, aphid-tending ants'' anti-herbivory effect decreased with leaf size. However, further analysis showed that this pattern was significant only at the beginning (May) and end (September) of the growing season. These results show that there is considerable variation in ants'' anti-herbivory effect even within an individual tree. Given that small leaves often are younger and more valuable than larger ones, our study suggests that a plant''s biotic partners protect its more valuable parts better.

Species covered 栎属 Quercus