北海道中山第2湿原での花粉分析と加速器質量分析(AMS)法 ^<14>C年代測定(第15回名古屋大学タンデトロン加速器質量分析計シンポジウム(平成14(2002)年度)報告)

DOI 機関リポジトリ HANDLE オープンアクセス

書誌事項

タイトル別名
  • Vegetational History Based on the Pollen Record and AMS- ^<14>C Dating, at Nakayama Mire of Loc.2 in South-Western Hokkaido, Japan, since the Late Glacial Substage(Proceedings of the 15^<th> Symposium on Researches Using the Tandetron AMS System at Nagoya University in 2002)

この論文をさがす

抄録

The vegetational history during the last ca.12,000 years of Nakayama mire of Loc.2 (ca. 43°N), in the province of Shiribeshi, south-western Hokkaido (870m a.s.l.) is reconstructed based on the pollen record and AMS- ^<14>C dating. The study site is now surrounded by Picea glehnii of subarctic forest species. Fossil pollen from a core taken from the site revealed the history of the vegetation since the Last Glacial Substage (after 12,000yrBP). AMS- ^<14>C dating was employed at several points where the plant pollen spectrum changed abruptly. During the Late glacial substage mixed forest composed mainly of Picea, Larix gmelinii, Pinus pumila, Betula and Alnus together with Selaginella selaginoides developed under a cold climate. Boreal coniferous forest characterized by Picea and Betula coexisting with a few aquatic plants developed after 10,830yr BP. After the large ratio of Quercus to Betula, declined aquatic plants such as Nuphar and Juglans together increased relative to Betula. These aquatic plants grew until about 8,500 yr BP. Quercus, which grows in warm climate and is associated with Ilex, persists through out this ca.7500 yr span. After 460yr BP pollen count of Picea spikes greatly then gradually decrease. The depth from 0.2m to surface shows rapid increase of Betula and decrease of Quercus. The surface appearance of Quercus is thought to result from wind transport because Quercus does not grow in the vicinity. The partial disappearance of the Picea forest presently covering widely the mires in the subalpine zone at 43°N suggests further global warming continues over the earth and that Betula forest will expand as driven by human activity.

収録刊行物

詳細情報

問題の指摘

ページトップへ