Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712.
Museo de Invertebrados G. B. Fairchild, Departmento de Zoología, Escuela de Biología, Facultad de Ciencias Naturales Exactas y Tecnología, Universidad de Panamá, 0824-00021, Panama City, Panama.
Proc Natl Acad Sci U S A. 2017 Nov 28;114(48):12761-12766. doi: 10.1073/pnas.1619271114. Epub 2017 Nov 10.
Animal pollination mediates both reproduction and gene flow for the majority of plant species across the globe. However, past functional studies have focused largely on seed production; although useful, this focus on seed set does not provide information regarding species-specific contributions to pollen-mediated gene flow. Here we quantify pollen dispersal for individual pollinator species across more than 690 ha of tropical forest. Specifically, we examine visitation, seed production, and pollen-dispersal ability for the entire pollinator community of a common tropical tree using a series of individual-based pollinator-exclusion experiments followed by molecular-based fractional paternity analyses. We investigate the effects of pollinator body size, plant size (as a proxy of floral display), local plant density, and local plant kinship on seed production and pollen-dispersal distance. Our results show that while large-bodied pollinators set more seeds per visit, small-bodied bees visited flowers more frequently and were responsible for more than 49% of all long-distance (beyond 1 km) pollen-dispersal events. Thus, despite their size, small-bodied bees play a critical role in facilitating long-distance pollen-mediated gene flow. We also found that both plant size and local plant kinship negatively impact pollen dispersal and seed production. By incorporating genetic and trait-based data into the quantification of pollination services, we highlight the diversity in ecological function mediated by pollinators, the influential role that plant and population attributes play in driving service provision, and the unexpected importance of small-bodied pollinators in the recruitment of plant genetic diversity.
动物传粉为全球大多数植物物种的繁殖和基因流动提供了媒介。然而，过去的功能研究主要集中在种子生产上；尽管这很有用，但这种对种子设定的关注并不能提供有关花粉介导基因流动的物种特异性贡献的信息。在这里，我们在超过 690 公顷的热带森林中量化了各个传粉者物种的花粉扩散。具体来说，我们使用一系列基于个体的传粉者排除实验以及基于分子的分数亲权分析，研究了一种常见热带树的整个传粉者群落的访问、种子生产和花粉扩散能力。我们调查了传粉者体型、植物大小（作为花展示的代理）、当地植物密度和当地植物亲缘关系对种子生产和花粉扩散距离的影响。我们的研究结果表明，虽然大体型的传粉者每次访问的种子数量更多，但体型较小的蜜蜂访问花朵的频率更高，它们负责超过 49%的所有远距离（超过 1 公里）花粉扩散事件。因此，尽管体型较小，但小型蜜蜂在促进远距离花粉介导的基因流动方面发挥着关键作用。我们还发现，植物大小和当地植物亲缘关系都对花粉扩散和种子生产产生负面影响。通过将遗传和性状数据纳入传粉服务的量化中，我们突出了传粉者介导的生态功能的多样性、植物和种群属性在驱动服务提供方面的影响作用，以及小型传粉者在植物遗传多样性招募中的意外重要性。
