Data from: Urban land use limits regional bumble bee gene flow

Potential declines in native pollinator communities and increased reliance on pollinator-dependent crops have raised concerns about native pollinator conservation and dispersal across human-altered landscapes. Bumble bees are one of the the most effective native pollinators, and are often the first to be extirpated in human-altered habitats, yet little is known about how bumble bees move across fine spatial scales and what landscapes promote or limit their gene flow. In this study, we examine regional genetic differentiation and fine scale relatedness patterns of the yellow-faced bumble bee, Bombus vosnesenskii, to investigate how current and historic habitat composition impact gene flow. We conducted our study across a landscape mosaic of natural, agricultural, and urban/suburban habitats, and we show that B. vosnesenskii exhibits low but significant levels of differentiation across the study system (FST = 0.019, Dest = 0.049). Most importantly, we reveal significant relationships between pairwise FST and resistance models created from contemporary land-use maps. Specifically, B. vosnesenskii gene flow is most limited by commercial, industrial, and transportation-related impervious cover. Finally, our fine-scale analysis reveals significant but declining relatedness between individuals at the 1- 9km spatial scale, most likely due to local queen dispersal. Overall, our results indicate that B. vosnesenskii exhibits considerable local dispersal and that regional gene flow is significantly limited by impervious cover associated with urbanization.

本土传粉昆虫群落的潜在衰退，以及人类对依赖传粉作物的依赖程度加深，引发了学界对本土传粉昆虫保护及其在受人类活动干扰的景观中扩散模式的担忧。熊蜂（bumble bee）是最为高效的本土传粉昆虫类群之一，且往往是受人类活动干扰的生境中最早出现局部灭绝的类群，但目前学界对熊蜂如何在精细空间尺度间移动，以及哪些景观类型会促进或限制其基因流（gene flow）仍知之甚少。本研究以黄脸熊蜂（Bombus vosnesenskii）为研究对象，分析其区域遗传分化与精细尺度亲缘关系模式，以探究当前与历史生境组成如何影响其基因流。本研究的研究区域涵盖自然、农业与城市/城郊生境构成的景观镶嵌体，结果显示黄脸熊蜂在整个研究系统中呈现出较低但显著的遗传分化水平（FST = 0.019，Dest = 0.049）。最为关键的是，本研究揭示了成对FST值与基于当代土地利用图构建的景观抗性模型之间存在显著关联。具体而言，黄脸熊蜂的基因流最易受到商业、工业及交通相关不透水地表的限制。最后，本研究的精细尺度分析显示，在1至9公里的空间尺度内，个体间的亲缘关系显著存在但随距离增加而下降，这一现象大概率源于本地蜂王的扩散行为。总体而言，本研究结果表明，黄脸熊蜂具备较强的本地扩散能力，而与城市化相关的不透水地表会显著限制其区域基因流。