PREMISE Pollen dispersal, the main component of overall plant gene flow, generally decreases with increasing distance from the pollen source, but the pattern of this relationship may differ among sites. Although site-based differences in pollen dispersal may lead to over- or underestimation of gene flow, no studies have investigated pollen dispersal patterns among differing urban site types, despite the incongruent range of habitats in urban areas. METHODS We used paternity assignment to assess pollen dispersal patterns in a wind-pollinated species (waterhemp; Amaranthus tuberculatus) and in an insect-pollinated species (tomato; Solanum lycopersicum) in experimental arrays at four disparate sites (two roof-level sites, two ground-level sites) in the New York (New York, USA) metropolitan area. RESULTS The number of seeds or fruits, a proxy for the number of flowers pollinated, decreased with increasing distance from the pollen donors at all sites for both species. However, the mean number of Amaranthus tuberculatus seeds produced at a given distance differed two-fold among sites, while the slope of the relationship between Solanum lycopersicum fruit production and distance differed by a factor of four among sites. CONCLUSIONS Pollen dispersal patterns may differ substantially among sites, both in the amount of pollen dispersed at a given distance and in the proportional decrease in pollen dispersal with increasing distance, and these effects may act independently. Accordingly, the capacity of plant species to adapt to climate change and other selection pressures may be different from predictions based on pollen dispersal patterns at a single location.

中文翻译：

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风媒传粉物种和昆虫传粉物种的花粉传播模式因地点而异

前提 花粉传播是整个植物基因流的主要组成部分，通常随着与花粉源距离的增加而减少，但这种关系的模式可能因地点而异。尽管基于地点的花粉传播差异可能导致基因流的高估或低估，但没有研究调查不同城市地点类型之间的花粉传播模式，尽管城市地区的栖息地范围不一致。方法 我们使用亲子鉴定在四个不同地点（两个屋顶水平地点，两个屋顶水平地点，两个地面站点）在纽约（美国纽约）大都市区。结果 种子或果实的数量，授粉的花朵数量的代表随着与两个物种所有地点的花粉捐赠者的距离增加而减少。然而，在给定距离生产的苋菜种子平均数量在不同地点之间相差两倍，而番茄果实产量与距离之间关系的斜率在地点之间相差四倍。结论 不同地点的花粉传播模式可能存在显着差异，无论是在给定距离的花粉量还是随着距离的增加，花粉传播的比例减少，这些影响可能独立起作用。因此，植物物种适应气候变化和其他选择压力的能力可能与基于单一地点的花粉传播模式的预测不同。