Past vegetation change recorded of a speleothem in the Akiyoshi-dai Plateau karst area, Yamaguchi, Japan

• KURISAKI Kousuke

  Department of Chemistry, Faculty of Sciences, Kyushu University

• NAKAMURA Hisashi

  Akiyoshi-dai Museum of Natural History

• KAWAMURA Hidehisa

  Kyushu Environmental Evaluation Association

• HATAE Kumi

  Department of Chemistry, Faculty of Sciences, Kyushu University

• YOSHIMURA Kazuhisa

  Department of Chemistry, Faculty of Sciences, Kyushu University

Bibliographic Information

Other Title

• 鍾乳石に記録された山口県秋吉台カルスト地域の植生変遷
• ショウニュウセキ ニ キロク サレタ ヤマグチケン アキヨシダイ カルスト チイキ ノ ショクセイ ヘンセン

Abstract

Speleothems record successive information on terrestrial paleoenvironment. The vegetation change in the Akiyoshi-dai Plateau, Yamaguchi Prefecture, was examined using the δ¹³C values of a stalagmite formed in the grassland area. The stalagmite δ¹³C values largely reflect those of the soil CO₂ derived from organic carbon associated with the δ¹³C values dependent on the vegetation type. The soil δ¹³C values in the forest areas (-23〜-21‰) were lower than that in the grassland area (-15‰). A 50/50 contribution from rock carbonate (+3‰) and the soil CO₂ resulted in HCO₃^- with δ¹³C values reflecting the vegetation. When the seepage water was exposed to cave air of a lower CO₂ concentration, the speleothems were formed from the water in the cave. The δ¹³C values of the speleothems in the forest areas were in the range of -7.8〜-5.5‰, whereas that in thegrassland area was -4.3‰. The 7 cm growing stalagmite sample from the Kitayamakita-no-yokoana Cave in the grassland was found to have recorded the artificial vegetation change in the Akiyoshi-dai Plateau as variations in the δ¹³C values of the carbonate. The average growth rate of a separate stalagmite (24μm y^-1) formed under circumstances similar to the stalagmite examined in the Akiyoshi-dai Plateau made it possible to estimate that yearly burning of the dead grass on the Akiyoshi-dai Plateau had started about 400 years ago.

Journal

• Chikyukagaku

  Chikyukagaku 40 (3), 245-251, 2006

  The Geochemical Society of Japan

Keywords

• terrestrial carbonates
• speleothem
• vegetation change
• carbon isotope ratio
• Akiyoshi-dai Plateau

Details

• CRID: 1390001205741655936
• NII Article ID: 110008680130
• NII Book ID: AN00141280
• DOI: 10.14934/chikyukagaku.40.245
• ISSN: 21885923
• ISSN: 03864073
• NDL BIB ID: 8077450
• Web Site: http://id.ndl.go.jp/bib/8077450
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I8077450
• Text Lang: ja
• Data Source:
  • JaLC
  • NDL
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed