Honey bees are the most economically important crop pollinator worldwide. They depend on a diversity of pollen for reproduction and colony growth. However, the influence of landscape composition on diversity and quantity of pollen collection by honey bees remains largely unexplored, particularly in variegated landscapes. Pollen on honey bees was trapped from 41 hives across ten sites in the Western Cape, South Africa during summer. Sampled hives were near eucalyptus trees surrounded by a high percentage of natural vegetation. Hives could therefore potentially be presented with a diverse range of flowers. To obtain a measure of relative abundance and representation of plant taxa pollen samples were collected at hives, sorted by color, weighed and DNA barcoded. Landscape analysis was performed to estimate the relative availability of the main floral resource-types and how this influenced the composition of pollen collected. Overall, eucalyptus made up the largest portion (∼49%) of pollen loads, the remainder was composed of 31 other taxa (12% native and 39% alien plants). An increase in the area of eucalyptus resulted in an increased as well as the relative amount of eucalyptus and natural pollen collected. Conversely, an increase in the area of eucalyptus resulted in a decrease in alien plant pollen and vice versa. Our results provide important quantitative evidence that shows the amount and diversity of pollen used by honey bees in summer appears to be disproportionately met by human-modified landscapes; whereas, natural vegetation, despite its large extent and diversity, performs a lower-level role during this season.

中文翻译：

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管理蜜蜂在杂色景观中使用的花粉来源的多样性

蜜蜂是全球经济上最重要的作物授粉媒介。它们依赖于花粉的多样性进行繁殖和菌落生长。然而，景观组成对蜜蜂采集花粉的多样性和数量的影响在很大程度上仍未得到探索，尤其是在杂色景观中。夏季，南非西开普省 10 个地点的 41 个蜂巢中收集了蜜蜂的花粉。采样的蜂箱靠近桉树，周围环绕着高比例的天然植被。因此，荨麻疹可能会出现各种各样的花朵。为了获得植物分类群的相对丰度和代表性的测量，在蜂箱收集花粉样品，按颜色分类，称重和 DNA 条形码。进行景观分析以估计主要花卉资源类型的相对可用性以及这如何影响收集的花粉组成。总体而言，桉树占花粉负荷的最大部分（~49%），其余由 31 个其他类群（12% 本地植物和 39% 外来植物）组成。桉树面积的增加导致收集到的桉树和天然花粉的数量以及相对数量的增加。相反，桉树面积的增加导致外来植物花粉的减少，反之亦然。我们的研究结果提供了重要的定量证据，表明夏季蜜蜂使用的花粉数量和多样性似乎不成比例地被人类改造的景观所满足；而自然植被，尽管其范围广且多样性，