Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA.
Graduate Group in Ecology, University of California, Davis, Davis, California, 95616, USA.
Am J Bot. 2021 Nov;108(11):2196-2207. doi: 10.1002/ajb2.1764. Epub 2021 Nov 23.
Many animals provide ecosystem services in the form of pollination including honeybees, which have become globally dominant floral visitors. A rich literature documents considerable variation in single visit pollination effectiveness, but this literature has yet to be extensively synthesized to address whether honeybees are effective pollinators.
We conducted a hierarchical meta-analysis of 168 studies and extracted 1564 single visit effectiveness (SVE) measures for 240 plant species. We paired SVE data with visitation frequency data for 69 of these studies. We used these data to ask three questions: (1) Do honeybees (Apis mellifera) and other floral visitors differ in their SVE? (2) To what extent do plant and pollinator attributes predict differences in SVE between honeybees and other visitors? (3) Is there a correlation between visitation frequency and SVE?
Honeybees were significantly less effective than the most effective non-honeybee pollinators but were as effective as the average pollinator. The type of pollinator moderated these effects. Honeybees were less effective compared to the most effective and average bird and bee pollinators but were as effective as other taxa. Visitation frequency and SVE were positively correlated, but this trend was largely driven by data from communities where honeybees were absent.
Although high visitation frequencies make honeybees important pollinators, they were less effective than the average bee and rarely the most effective pollinator of the plants they visit. As such, honeybees may be imperfect substitutes for the loss of wild pollinators, and safeguarding pollination will benefit from conservation of non-honeybee taxa.
许多动物以传粉的形式提供生态系统服务，包括蜜蜂，它们已成为全球占主导地位的花卉传粉者。大量文献记录了单次访问传粉效率的显著差异，但这些文献尚未得到广泛综合，以确定蜜蜂是否是有效的传粉者。
我们对 168 项研究进行了层次元分析，并为 240 种植物提取了 1564 个单次访问效率（SVE）测量值。我们将 SVE 数据与其中 69 项研究的访问频率数据进行配对。我们使用这些数据来回答三个问题：（1）蜜蜂（Apis mellifera）和其他访花者在 SVE 方面是否存在差异？（2）植物和传粉者特征在多大程度上预测了蜜蜂和其他访花者之间 SVE 的差异？（3）访问频率和 SVE 是否存在相关性？
蜜蜂的传粉效率明显低于最有效的非蜜蜂传粉者，但与平均传粉者相当。传粉者的类型调节了这些效应。与最有效的鸟类和蜜蜂传粉者相比，蜜蜂的传粉效率较低，但与其他类群的传粉者相当。访问频率和 SVE 呈正相关，但这种趋势主要是由没有蜜蜂的群落中的数据驱动的。
尽管高访问频率使蜜蜂成为重要的传粉者，但它们的传粉效率低于平均蜜蜂，很少是它们访问的植物中最有效的传粉者。因此，蜜蜂可能不是野生传粉者丧失的完美替代品，保护传粉将受益于非蜜蜂类群的保护。
