Which traits optimize plant benefits? Meta-analysis on the effect of partner traits on the outcome of an ant-plant protective mutualism

1. Theoretical models on mutualism dynamics predict that partner traits may influence the outcome of mutualistic interactions. However, most empirical data on this issue is restricted to case studies, limiting our ability to reach a more widespread comprehension of the role of partner traits on the dynamic of mutualisms. 2. We investigated how the outcome of protective mutualisms between ants and plants bearing extrafloral nectaries (EFNs) is influenced by the traits of EFNs and ants feeding on EFNs. We used a meta-analytical approach based on 35 studies investigating the effect of ant attendance on the herbivores and reproductive performance of EFN-bearing plants. We evaluated how variation in the EFN vascularization and location on plants and the ant aggressiveness can modulate the effect of ant attendance on the plants. 3. Both plant and ant traits investigated here drove the outcome of the protective mutualism for EFN-bearing plants. Plants exclusively bearing EFNs near reproducti...1. 互利共生动力学（mutualism dynamics）的理论模型预测，共生伙伴的性状可影响互利互作的最终结果。然而，当前该领域的绝大多数实证数据均局限于个案研究，这极大限制了我们对共生伙伴性状在共生动力学中所扮演角色的更全面认知。 2. 本研究聚焦于具花外蜜腺（extrafloral nectaries, EFNs）的植物与蚂蚁间的保护性互利共生关系，探讨其结果如何受到花外蜜腺性状以及取食花外蜜腺的蚂蚁性状的调控。我们采用基于35项相关研究的元分析方法（meta-analytical approach），探究蚂蚁访栖对具花外蜜腺植物的植食性动物种群及繁殖表现的影响，并评估了花外蜜腺的脉管结构、在植物上的分布位置，以及蚂蚁的攻击性这三者的差异，如何调节蚂蚁访栖对植物的作用效应。 3. 本研究所考察的植物与蚂蚁性状，均会调控具花外蜜腺植物的保护性互利共生关系的最终结果。仅在繁殖相关区域附近生有花外蜜腺的植物...