Data from: Climate oscillation during the Quaternary associated with landscape heterogeneity promoted allopatric lineage divergence of a temperate tree Kalopanax septemlobus (Araliaceae) in East Asia

We investigated the biogeographic history of Kalopanax septemlobus, one of the most widespread temperate tree species in East Asia, using a combined phylogeographic and palaeodistribution modelling approach. Range-wide genetic differentiation at nuclear microsatellites (G′ST = 0.709; 2205 samples genotyped at five loci) and chloroplast DNA (GST = 0.697; 576 samples sequenced for 2055 bp at three fragments) was high. A major phylogeographic break in Central China corresponded with those of other temperate species and the spatial delineation of the two temperate forest subkingdoms of East Asia, consistent with the forests having been isolated within both East and West China for multiple glacial–interglacial cycles. Evidence for multiple glacial refugia was found in most of its current range in China, South Japan and the southernmost part of the Korean Peninsula. In contrast, lineage admixture and absence of private alleles and haplotypes in Hokkaido and the northern Korean Peninsula support a postglacial origin of northernmost populations. Although palaeodistribution modelling predicted suitable climate across a land-bridge extending from South Japan to East China during the Last Glacial Maximum, the genetic differentiation of regional populations indicated a limited role of the exposed sea floor as a dispersal corridor at that time. Overall, this study provides evidence that differential impacts of Quaternary climate oscillation associated with landscape heterogeneity have shaped the genetic structure of a wide-ranging temperate tree in East Asia.本研究采用谱系地理学（phylogeography）与古分布建模（palaeodistribution modelling）相结合的方法，探究了东亚分布最广的温带乔木物种之一刺楸（Kalopanax septemlobus）的生物地理历史。基于核微卫星（nuclear microsatellites）与叶绿体DNA（chloroplast DNA）的全分布区遗传分化水平均较高：核微卫星分析共对2205份样本的5个位点（locus，复数为loci）完成基因分型，其G′ST值为0.709；叶绿体DNA分析共对576份样本的3个片段完成2055 bp测序，其GST值为0.697。华中地区存在的主要谱系地理断点（phylogeographic break），与其他温带物种的谱系地理断点以及东亚两个温带森林亚界（temperate forest subkingdoms）的空间分界相吻合，这表明在多次冰期-间冰期循环（glacial–interglacial cycles）中，中国东部与西部的森林曾长期相互隔离。在中国、日本南部以及朝鲜半岛最南部的大部分当前分布区内，均发现了存在多处冰期避难所（glacial refugia）的证据。与之相反，北海道与朝鲜半岛北部存在谱系混合（lineage admixture）现象，且未检测到私有等位基因（private alleles）与单倍型（haplotypes），这支持了该区域最北部种群为冰期后起源的结论。尽管古分布建模预测，末次盛冰期（Last Glacial Maximum）时日本南部至中国东部之间的陆桥（land-bridge）区域气候适宜生存，但区域种群的遗传分化表明，当时裸露海床作为扩散廊道（dispersal corridor）的作用十分有限。综上，本研究提供了可靠证据，表明与景观异质性（landscape heterogeneity）相关的第四纪气候振荡（Quaternary climate oscillation）的差异化影响，塑造了东亚这一广布温带乔木的遗传结构（genetic structure）。