Japanese researchers investigated whether a dominant tree of warm temperate broadleaved forests in Japan, Castanopsis sieboldii, underwent northward migration over hundreds of kilometres from Last Glacial Maximum (LGM) (about 21,000 years ago) refugia in the Ryukyu archipelago and southern Kyushu. Fossil pollen there indicates the LGM survival of broadleaved evergreen forests. Or it may in fact have been able to survive closer to its present range in colder areas such as the coast of the Japan Sea and the Pacific Ocean side of eastern Honshu during the Last Glacial Maximum (LGM). Using a combined genetic analysis and modelling approach, it was found that the East Japan populations, where few pollen fossil records exist, survived in situ during the LGM on both the Japan Sea and Pacific coasts and were not established via expansion after the LGM from southern areas. Their findings were published online in Heredity.