Migration and development for Cryptomeria japonica since the last glacial period in western Japan

根据这项研究和以前的孢粉学数据(Takahara and Takeoka，1992；Takahara et al.，1999)，很明显，柳杉在日本西部日本海的沿海走廊上有全冰川避难所。日本龟甲的这一推论(Tsukada，1980；1982；1986)得到了来自冲绳群岛的证据的证实。此外，这项研究还表明，日本古木半岛的日本血吸虫种群数量比日本西部的其他地点要多。在和歌湾地区，也被视为日本血吸虫的避难所，该物种在全新世早期突然增加，然后蔓延到整个全新世(Yasuda，1982；Takahara和Takeoka，1992；Takahara等，1999)。另一方面，位于日本中部中部附近日本海冲绳群岛以南的新济湖，全新世早期的日本冰盖发育并不明显(Oonishi，1977年)，这可能是因为日本冰盖晚期海平面的快速上升阻止了日本冰盖从古冲绳半岛向南迁徙到现在的中部中部沿海地区，编制了日本冰盖晚期18000、11000、8000、6000年、4000年和2000年的日本孢粉百分比。这些图表显示了日本柳杉从末次冰盛期到全新世晚期的迁移和发展。

Based on this study and previous palynological data (Takahara and Takeoka, 1992 ; Takahara et al., 1999), it is clear that Cryptomeria japonica had full-glacial refugia along the coastal corridor of the Sea of Japan, western Japan. The inference of C.japonica refugia (Tsukada, 1980 ; 1982 ; 1986) is confirmed by the evidence from Oki Islands of this study. Also, this study indicates that the population of C.japonica in the Palaeo-Oki Peninsula was larger than at other sites in western Japan. In the Wakasa Bay area, which is also regarded as a C.japonica refugia, the species increased abruptly in the early Holocene, and then spread throughout the Holocene (Yasuda, 1982 ; Takahara and Takeoka, 1992 ; Takahara et al., 1999). On the other hand, around Lake Shinji, which is located south of Oki Islands on the Sea of Japan coast near the middle of the Chugoku region, development of C.japonica during the early Holocene is not evident (Onishi, 1977), probably because southward migration of C.japonica from the Palaeo-Oki Peninsula into the present coastal area of the middle Chugoku region was prevented by a rapid rise in sea-levels in the late-glacialyptomeria japonica pollen percentages at 18000, 11000, 8000, 6000, 4000 and 2000 yr BP in western Japan were compiled on longitude-latitude and longitude-altitude diagrams. These diagrams shows migration and development for Cryptomrtia japonica from the last glacial maximum to the late Holocene.