Chapman R E, Wang J, Bourke A F G
Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK.
Mol Ecol. 2003 Oct;12(10):2801-8. doi: 10.1046/j.1365-294x.2003.01957.x.
Conservation biologists, evolutionary ecologists and agricultural biologists require an improved understanding of how pollinators utilize space and share resources. Using microsatellite markers, we conducted a genetic analysis of space use and resource sharing at several spatial scales among workers of two ecologically dissimilar bumble bee species (Bombus terrestris and B. pascuorum) foraging in an urban landscape (London, UK). At fine scales, the relatedness of workers visiting small patches of flowers did not differ significantly from zero. Therefore, colonies shared flower patches randomly with other colonies, suggesting that worker scent-marks deterring visits to unrewarding flowers have not evolved as signals benefiting nestmates. To investigate space use at intermediate scales, we developed a program based on Thomas & Hill's maximum likelihood sibship reconstruction method to estimate the number of colonies utilizing single sites. The average number of colonies (95% confidence limits) sending workers to forage at sites of approximately 1 ha in area was 96 colonies (84-118) in B. terrestris and 66 colonies (61-76) in B. pascuorum. These values are surprisingly high and suggested that workers travelled far from their colonies to visit the sites. At the landscape scale, there was little or no genetic differentiation between sites. We conclude that urban habitats support large bumble bee populations and are potentially valuable in terms of bumble bee conservation. In addition, bumble bee-mediated gene flow in plants is likely to occur over large distances and plant-bumble bee conservation requires landscape-scale action.
保护生物学家、进化生态学家和农业生物学家需要更好地了解传粉者如何利用空间和共享资源。我们使用微卫星标记，对在城市景观（英国伦敦）中觅食的两种生态习性不同的熊蜂物种（地熊蜂和帕斯库熊蜂）的工蜂在几个空间尺度上的空间利用和资源共享进行了遗传分析。在精细尺度上，访问小花斑块的工蜂之间的亲缘关系与零没有显著差异。因此，蜂群与其他蜂群随机共享花斑块，这表明阻止访问无回报花朵的工蜂气味标记并未进化为使巢友受益的信号。为了研究中等尺度上的空间利用情况，我们基于托马斯和希尔的最大似然同胞关系重建方法开发了一个程序，以估计利用单个地点的蜂群数量。在面积约为1公顷的地点觅食的地熊蜂工蜂所来自的蜂群平均数量（95%置信区间）为96个蜂群（84 - 118个），帕斯库熊蜂为66个蜂群（61 - 76个）。这些数值高得出奇，表明工蜂从其蜂群远行至这些地点觅食。在景观尺度上，不同地点之间几乎没有遗传分化。我们得出结论，城市栖息地支持大量熊蜂种群，就熊蜂保护而言具有潜在价值。此外，熊蜂介导的植物基因流动可能远距离发生，植物 - 熊蜂保护需要景观尺度的行动。
