Milner James R D, Bloom Elias H, Crowder David W, Northfield Tobin D
Centre for Tropical Environmental and Sustainability Studies College of Science and Engineering James Cook University Cairns Qld Australia.
Department of Entomology Michigan State University East Lansing MI USA.
Ecol Evol. 2020 Apr 12;10(10):4407-4418. doi: 10.1002/ece3.6207. eCollection 2020 May.
Pollinators are introduced to agroecosystems to provide pollination services. Introductions of managed pollinators often promote ecosystem services, but it remains largely unknown whether they also affect evolutionary mutualisms between wild pollinators and plants.Here, we developed a model to assess effects of managed honey bees on mutualisms between plants and wild pollinators. Our model tracked how interactions among wild pollinators and honey bees affected pollinator and plant populations.We show that when managed honey bees have a competitive advantage over wild pollinators, or a greater carrying capacity, the honey bees displace the wild pollinator. This leads to reduced plant density because plants benefit less by visits from honey bees than wild pollinators that coevolved with the plants.As wild pollinators are displaced, plants evolve by increasing investment in traits that are attractive for honey bees but not wild pollinators. This evolutionary switch promotes wild pollinator displacement. However, higher mutualism investment costs by the plant to the honey bee can promote pollinator coexistence.Our results show plant evolution can promote displacement of wild pollinators by managed honey bees, while limited plant evolution may lead to pollinator coexistence. More broadly, effects of honey bees on wild pollinators in agroecosystems, and effects on ecosystem services, may depend on the capacity of plant populations to evolve.
传粉者被引入农业生态系统以提供授粉服务。引入人工管理的传粉者通常会促进生态系统服务，但它们是否也会影响野生传粉者与植物之间的进化互利共生关系，在很大程度上仍不清楚。在此，我们开发了一个模型来评估人工饲养的蜜蜂对植物与野生传粉者之间互利共生关系的影响。我们的模型追踪了野生传粉者与蜜蜂之间的相互作用如何影响传粉者和植物种群。我们发现，当人工饲养的蜜蜂比野生传粉者具有竞争优势或更大的承载能力时，蜜蜂会取代野生传粉者。这导致植物密度降低，因为与共同进化的野生传粉者相比，植物从蜜蜂的访花中获益更少。随着野生传粉者被取代，植物通过增加对吸引蜜蜂而非野生传粉者的性状的投入而进化。这种进化转变促进了野生传粉者的取代。然而，植物对蜜蜂更高的互利共生投入成本可以促进传粉者的共存。我们的结果表明，植物进化可以促进人工饲养的蜜蜂取代野生传粉者，而有限的植物进化可能导致传粉者共存。更广泛地说，蜜蜂对农业生态系统中野生传粉者的影响以及对生态系统服务的影响，可能取决于植物种群的进化能力。
