Data from: The critical role of local refugia in postglacial colonization of Chinese pine: joint inferences from DNA analyses, pollen records, and species distribution modeling

The importance of long-distance migration from low to high latitudes relative to local spread from northern refugia after the Last Glacial Maximum (LGM) remains a focus of debate for many temperate tree species. We assessed the dynamics of Chinese pine (Pinus tabulaeformis), a widespread species endemic to northern China, since the LGM by integrating cytoplasmic DNA data, mapped pollen records and ecological niche modeling. Genetic variation among 544 individuals from 50 populations spanning the entire natural species range revealed eight genetic clusters with distinct geographic distribution, indicating glacial lineages likely originating from multiple local microrefugia. Palynological evidence suggested that the northernmost part of the natural distribution originated from local postglacial spread. Niche modeling indicated high probability of the species being present in the area of the Loess Plateau and coastal areas north of the Yangtze River during the LGM. The three lines of evidence jointly suggest that the species persisted through the last glaciation in the mountains surrounding the Loess Plateau of northern China and that the current distribution of the species originated primarily from the spread of local refugial populations, instead of long-distance migration. These results cast doubt on the notion that Chinese pine migrated from areas south of the Yangtze River and underscore the importance of northern refugia.末次冰盛期（Last Glacial Maximum，LGM）后，相较于北方避难所的本地扩散，从低纬度向高纬度的长距离迁移对诸多温带乔木物种的重要性，始终是学界争论的核心议题。本研究以中国北方特有广布乔木油松（Pinus tabulaeformis）为研究对象，整合细胞质DNA（cytoplasmic DNA）数据、已空间制图的花粉记录与生态位模型（ecological niche modeling），解析其自末次冰盛期以来的种群动态。对覆盖该物种全部自然分布区的50个种群的544个个体开展遗传变异分析，结果显示其存在8个地理分布特征鲜明的遗传簇，表明冰期谱系大概率起源于多个局地微型避难所。孢粉学证据表明，该物种自然分布区的最北端种群源自冰期后的本地扩散。生态位模型结果显示，末次冰盛期时期，该物种在黄土高原区域与长江以北沿海地区存在的概率极高。三项独立证据共同证实：该物种在末次冰期期间存活于中国北方黄土高原周边的山地中，当前的自然分布格局主要源自本地避难所种群的扩散，而非长距离迁移。本研究结果对“油松源自长江以南区域迁移”这一观点提出了质疑，并凸显了北方避难所的重要性。