阿蘇火山南西麓のテフラ累層における最近約3万年間の植物珪酸体分析 A 30,000-year Phytolith Record of a Tephra Sequence at the Southwestern Foot of Aso Volcano, Japan
A 30,000-yr record of vegetation history has been constructed using a phytolith analysis of a tephra sequence located at the Kawahara No.3 archaeological site, southwestern foot of Aso Volcano, central Kyushu, southwestern Japan. The sequence was divided into three zones: Zone 3 (><i>ca</i>. 31 cal ka), Zone 2 (31-13.5 cal ka), and Zone 1 (13.5-0 cal ka) in ascending order. Gramineae phytoliths were predominately detected at most horizons, whereas a small amount of arboreal phytolith was observed mainly at Late Holocene horizons. Zone 3 was dominated by a phytolith of <i>Sasa</i> (mainly <i>Sasa</i> sect. Crassinodi), a cool-temperature dwarf bamboo. However, vegetation composed mainly of <i>Sasa</i> dwarf bamboo had declined slightly in Zone 2, which corresponds to the Last Glacial Maximum. During the Holocene (Zone 1) the <i>Sasa</i> grassland dominated consistently, but phytolith of <i>Pleioblastus</i> (a warm temperature dwarf bamboo) and arboreal such as <i>Distylium</i> increased from 7,300 years ago.
地學雜誌 117(4), 704-717, 2008-09-25
Tokyo Geographical Society