일본 남서부 大田市(Ohda-city)일대의 식생변화와 Lake Shinji에서 보고된 화분분대를 대비하기 위해 피근호(Lake Hane) 퇴적물의 화분분석을 실시하였다. OH94 코어시료(19.7 m)의 화분분석결과, 하부로부터 Cyclobalanopsis-Catanopsis 화분대와, Gramineae 화분대로 나누어진다. Cyclcbalanopsis-Catanopis 화분대는 Cyclobalanopsis아대, Catanopsis아대 그리고, Podocarpus아대로 세분할 수 있고, Gramineae 화분대는 Cryptomeria아대와 Cyclobalanopsis-Quercus아대로 세분된다. 특히 Cyclobalanopsis-Cutanopsis 화분대에서 K-Ah 테프라를 동정하였고, 이 결과로부터 Cyclobalanopsis-Catanopsis 화분대가 $6,300_{14}$CBP이전부터 시작되었음을 알 수 있었다.
The pollen of the sediments from the Lake Hane were analysed for reconstruction of vegetation history around Ohda-City in Southwest Japan, and the correlation with the pollen zone reported for the Lake Shinji. From the pollen assemblages of 29 samples from core OH94 (19.7 m), two pollen zone were established, and they were subdivided into five subzones in ascending order as following; Cyclobalanopsis-Catanopsis pollen zone (Cyclobalanopsis subzone, Catanopsis subzone and, Podocarpus subzone), and Gramineae pollen zone (Cryptomeria subzone and Cyclobalanopsis-Quercus subzone). The K-Ah volcanic ash is identified in the Cyclobalanopsis-Catanopsis pollen zone. We estimated the beginning of the Cyclobalanopsis-Catanopsis pollen zone was before c.a. 6,300 BP.
