Ants benefit myrmecophytic plants by two main activities defending them from herbivores and offering nutrients. Ants’ territorial defence behaviour also benefits their myrmecophytic plants; in the case of trees, this behaviour includes eliminating structural parasites (epiphytes and lianas). These benefits could also occur with myrmecophytic epiphytes by decreasing the abundance of competing epiphytes. In two subunits of a tropical dry forest in the centre of Mexico, we (i) recorded the diversity of ants associated with the myrmecophyte Tillandsia caput-medusae, and experimentally tested: (ii) the effect of the ants associated with the myrmecophyte in the removal of its seeds and the seeds of other sympatric non-myrmecophyte species of Tillandsia; and (iii) if seed remotion by ants corresponds with epiphyte load in the preferred (Bursera copallifera) and limiting phorophyte species (B. fagaroides, Ipomoea pauciflora and Sapium macrocarpum). In five trees per species, we tied seed batches of T. caput-medusae, T. hubertiana, T. schiedeana and T. recurvata. One seed batch was close, and the other far away from a T. caput-medusae with active ants. Between forest subunits, ant richness was similar, but diversity and evenness differed. Ants diminish seed establishment of all the Tillandsia species; this effect is stronger in the forest subunit with a large ant diversity, maybe because of ant competition. Seed remotion by ants is independent of phorophyte species identity. Although ants can provide benefits to T. caput-medusae, they also could be lowering their abundance.

中文翻译：

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降低密度：与 myrmecophyte Tillandsia caput-medusae 相关的蚂蚁减少了附生植物的建立

蚂蚁通过保护它们免受食草动物的侵害和提供营养的两项主要活动而使 myrmecophytic 植物受益。蚂蚁的领土防御行为也有利于它们的微生植物；就树木而言，这种行为包括消除结构寄生虫（附生植物和藤本植物）。通过减少竞争附生植物的丰度，这些好处也可能发生在 myrmecophytic 附生植物中。在墨西哥中部热带干燥森林的两个亚基中，我们 (i) 记录了与 myrmecophyte Tillandsia caput-medusae 相关的蚂蚁的多样性，并进行了实验测试：(ii) 与 myrmecophyte 相关的蚂蚁在去除它的种子和其他同域的非 myrmecophyte 铁兰属物种的种子；(iii) 如果蚂蚁的种子移走与首选的附生植物负荷 (Bursera copallifera) 和限制性的 phorophyte 物种 (B. fagaroides、Ipomoea pauciflora 和 Sapium macrocarpum) 相对应。在每个物种的五棵树中，我们将 T. caput-medusae、T. hubertiana、T. schiedeana 和 T. recurvata 的种子批次捆绑在一起。一批种子离得很近，而另一批则远离带有活跃蚂蚁的 T. caput-medusae。在森林亚基之间，蚂蚁丰富度相似，但多样性和均匀度不同。蚂蚁减少了所有凤梨物种的种子形成；这种效应在蚂蚁多样性大的森林亚基中更强，可能是因为蚂蚁竞争。蚂蚁的种子转移与植物的物种身份无关。虽然蚂蚁可以为 T. caput-medusae 带来好处，但它们也可能会降低它们的数量。