Data from: Plant dispersal in the sub-Antarctic inferred from anisotropic genetic structure

Climatic conditions and landscape features often strongly affect species’ local distribution patterns, dispersal, reproduction and survival, and may therefore have considerable impacts on species' fine-scale spatial genetic structure (SGS). In this paper we demonstrate the efficacy of combining fine-scale SGS analyses with isotropic and anisotropic spatial autocorrelation techniques to infer the impact of wind patterns on plant dispersal processes. We genotyped 1304 Azorella selago (Apiaceae) specimens, a wind-pollinated and wind-dispersed plant, from four populations distributed across sub-Antarctic Marion Island. SGS was variable with Sp values ranging from 0.001 to 0.014, suggesting notable variability in dispersal distance and wind velocities between sites. Nonetheless, the data supported previous hypotheses of a strong NW – SE gradient in wind strength across the island. Anisotropic autocorrelation analyses further suggested that dispersal is strongly directional, but varying between sites depending on the local prevailing winds. Despite the high frequency of gale-force winds on Marion Island, gene dispersal distance estimates (σ) were surprisingly low (< 10 m), most likely because of a low pollen dispersal efficiency. An SGS approach in association with isotropic and anisotropic analyses provides a powerful means to assess the relative influence of abiotic factors on dispersal, and allow inferences that would not be possible without this combined approach.气候条件与景观格局通常会显著影响物种的局部分布模式、扩散、繁殖与存活，进而对物种的精细尺度空间遗传结构（fine-scale spatial genetic structure, SGS）产生重要影响。本研究证明，将精细尺度空间遗传结构分析与各向同性、各向异性空间自相关技术相结合，可有效推断风型对植物扩散过程的影响。我们对分布于亚南极马里恩岛的4个种群共1304份Azorella selago（伞形科，Apiaceae）样本进行了基因分型，该物种为风媒传粉、风力扩散植物。空间遗传结构存在差异，Sp值介于0.001至0.014之间，表明不同样点间的扩散距离与风速存在显著差异。尽管如此，本研究数据验证了此前提出的"全岛风速呈西北-东南向显著梯度分布"的假说。各向异性自相关分析进一步表明，植物扩散具有强烈的方向性，但不同样点的扩散方向会随当地盛行风况发生变化。尽管马里恩岛强暴风天气频发，但基因扩散距离估计值（σ）却低至不足10米，这很可能是由于花粉扩散效率较低所致。将空间遗传结构分析与各向同性、各向异性分析相结合，可为评估非生物因子对扩散的相对影响提供强有力的手段，且能得出单一分析方法无法实现的推论。