11:30 AM - 11:50 AM
[MIS15-10] Investigating changes in the distribution of Japanese cedar in the Japan Sea side area during the post-glacial period based on pollen analysis
★Invited Papers
Keywords:Cryptomeria japonica, post glacial, pollen analysis
Japanese cedar (Cryptomeria japonica) is the most common plantation species and is naturally and widely distributed in Japan. Many studies have investigated changes in the distribution of Japanese cedar, especially after the last glacial period. We conducted pollen analysis in the northern area of Japan Sea side to verify the established theory that Japanese cedar has expanded from the refugia at the Wakasa bay area after the last glacial.
We performed pollen analysis, identification of tephra and 14C dating at the foot of Mt. Chokai, Akita prefecture, to reconstruct the vegetation history of Japanese cedar. Results showed that the occurrence rate of Cryptomeria pollen was 2%–3% in the late-glacial period and was low but sustained until the middle of the post-glacial period. Afterward, the occurrence rate of Cryptomeria pollen began to increase in 3300 cal BP and dominated between 3000 and 1000 cal BP. We also recognized a similar occurrence pattern of Cryptomeria pollen at several study sites in the early age of the post-glacial period. These findings support the assumption that the natural Japanese cedar communities in Akita prefecture have expanded, not from the refugia of the Wakasa bay area, but from the local communities (endemic small refugia) that survived the last glacial period.
We performed pollen analysis, identification of tephra and 14C dating at the foot of Mt. Chokai, Akita prefecture, to reconstruct the vegetation history of Japanese cedar. Results showed that the occurrence rate of Cryptomeria pollen was 2%–3% in the late-glacial period and was low but sustained until the middle of the post-glacial period. Afterward, the occurrence rate of Cryptomeria pollen began to increase in 3300 cal BP and dominated between 3000 and 1000 cal BP. We also recognized a similar occurrence pattern of Cryptomeria pollen at several study sites in the early age of the post-glacial period. These findings support the assumption that the natural Japanese cedar communities in Akita prefecture have expanded, not from the refugia of the Wakasa bay area, but from the local communities (endemic small refugia) that survived the last glacial period.