Data from: Ants at plant wounds – a little-known trophic interaction with evolutionary implications for ant-plant interactions

Extrafloral nectaries (EFNs) allow plants to engage in mutualisms with ants preventing herbivory in exchange for food. EFNs occur scattered through the plant phylogeny and likely evolved independently from herbivore-created wounds subsequently visited by ants collecting leaked sap. Records of wound-feeding ants are, however, anecdotal. By surveying 38,000 trees from 40 species, we conduct the first quantitative ecological study of this overlooked behavior. Ant-wound interactions were widespread (0.5% of tree individuals) and occurred on 23 tree species. Interaction networks were opportunistic, closely resembling ant-EFNs networks. Fagaceae, a family lacking EFNs, were strongly overrepresented. For Fagaceae, ant occurrence at wounds correlated with species-level leaf damage, potentially indicating that wounds may attract mutualistic ants, supporting the hypothesis of ant-tended wounds as precursors of ant-EFNs mutualisms. Given the commonness of herbivore wounds, wound sap as steadily available food source might furthermore help to explain the overwhelming abundance of ants in (sub)tropical forest canopies.花外蜜腺（Extrafloral Nectaries, EFNs）可使植物与蚂蚁建立互利共生关系：植物为蚂蚁提供食物，蚂蚁则帮助植物抵御植食性生物。花外蜜腺在植物系统发育中呈零散分布状态，且极有可能独立演化自植食性生物造成的伤口——这类伤口后续会被采集渗漏汁液的蚂蚁造访。然而，此前关于蚂蚁取食伤口汁液的记录仅为轶事性报道。本研究通过对40个物种的38000株树木开展调查，完成了针对这一被忽视行为的首次定量生态学研究。结果显示，蚂蚁与伤口的交互现象广泛存在：在受访个体中占比0.5%，且覆盖23个树木物种。二者的交互网络具有机会主义特征，与蚂蚁-花外蜜腺交互网络高度相似。缺乏花外蜜腺的壳斗科（Fagaceae）在样本中占比显著偏高。就壳斗科而言，伤口处的蚂蚁出现情况与物种水平的叶片损伤程度呈显著相关，这暗示伤口或许能够吸引互利共生的蚂蚁，从而支持了"被蚂蚁照料的伤口是蚂蚁-花外蜜腺共生关系起源雏形"这一假说。考虑到植食性伤口的普遍性，作为稳定可获取食物来源的伤口汁液，或可进一步解释（亚）热带森林冠层中蚂蚁数量极为丰富的现象。