湖底堆積物(BDP96-1)の花粉分析からみたバイカル湖周辺の第四紀植生変遷史  [in Japanese] Quaternary Vegetation History Based on Pollen Analysis of Bottom Sediment (BDP96-1) Taken from Lake Baikal, Russia  [in Japanese]

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Abstract

バイカル湖の湖底から得られた5.1Maをカバーする全長200mコア(BDP96-1)のうち,第四紀に相当する上部の深度80m以浅についての花粉分析を行い,植生変遷について考察した.産出した化石花粉・胞子のうち51種類を同定したが,マツ科針葉樹が70~80%を占め,その産出状況に特色がみられた.すなわち,大量の化石花粉・胞子の産出する多産層(間氷期,湿潤期)と,草本花粉・胞子がごくわずかに産出するだけの稀産層(氷期,乾燥期)が交互に現れている.上部80mの2Maに32回のサイクルが認められ,δ<sup>18</sup>O曲線とほぼ調和的な環境変動を記録している.また,マツ科のツガ属と落葉広葉樹のクマシデ属,コナラ亜属,クリ属,ニレ科,ハシバミ属,カエデ属は第四紀前半に絶滅してしまい,後半以降のバイカル湖周辺のタイガはマツ科針葉樹とカバノキ属を中心とした比較的単純な植生からなる森林が継続した.

Lake Baikal, situated in southeastern Siberia, Russia, is the oldest and deepest freshwater lake in the world. During February-March 1996, long-bore drilling to the bottom depth of 300m was done in order to investigate the palaeolimnological record; a 200m core of various sedimentary units was picked up. An 80m sediment sample of the uppermost core was examined palynologically at intervals of ca. 10cm. The investigated part of the core covers aproximately the last 2Ma of the Quaternary including the Pleistocene and Holocene. Two major vegetation types were recognized alternately from the bottom to the surface. One type had many kinds of abundant fossil arboreal pollen originating from the Siberian taiga: subarctic needle-leaved forest and non-arboreal pollen, which was dominant during interglacial periods. The other type comprised only a few kinds of sparse fossil non-arboreal pollens such as <i>Artemisia</i>, Chenopodiaceae and Gramineae originating from the tundra and steppe, and was more evident druing glacial periods. Thirty two glacial-interglacial cycles were recognized, and the cyclic changes in vegetation corresponded harmoniously with δ<sup>18</sup>O marine isotope stage. The abundant vegetation of the Siberian taiga in the Tertiary gradually became simpler during the Quaternary. A needle-leaved tree <i>Tsuga</i> and some deciduous broad-leaved trees such as <i>Carpinus</i>, <i>Lepidobalanus</i>, Ulmaceae, and <i>Corylus</i> became extinct due to cooling of the climate during the first half of the Quaternary. The main taxa of the taiga in the latter half of the Quaternary were Pinaceae except for <i>Tsuga</i> and <i>Betula</i>.

Journal

  • The Quaternary Research (Daiyonki-Kenkyu)

    The Quaternary Research (Daiyonki-Kenkyu) 41(3), 171-184, 2002-06-01

    Japan Association for Quaternary Research

References:  41

Cited by:  2

Codes

  • NII Article ID (NAID)
    10008631895
  • NII NACSIS-CAT ID (NCID)
    AN0034136X
  • Text Lang
    JPN
  • Article Type
    Journal Article
  • ISSN
    04182642
  • NDL Article ID
    6178629
  • NDL Source Classification
    ZM49(科学技術--地球科学--地質)
  • NDL Call No.
    Z15-67
  • Data Source
    CJP  CJPref  NDL  J-STAGE 
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