【摘要】 通过对正构烷烃分布特点的系统分析,恢复了青藏高原东北部全新世以来泥炭的生物记录。正构烷烃nC25和nC31相对含量在泥炭序列中呈现的规律性变化揭示出,在全新世期间因气候的变化幅度不同而引起了生物形态种或化学种的取代,即当气候变化幅度大时,沼泽地可能出现了水生植物和陆生植物群落之间的相互演替;当气候波动小时,则出现了分子(化学)种之间的相互取代。将这一研究结果与同一地区的孢粉资料对比、验证,分析了它们之间的差异性,提出了类脂分子化石可作为恢复植被的有效工具,与孢粉相结合,可获取更为全面的植被演化历史。这一研究为青藏高原地区全新世以来的有关生物学信息提供了新的证据。更多还原

【Abstract】 The distribution of the n-alkanes in the Hongyuan peat core of the northeastern Qinghai-xizang Plateau was systematically analyzed based on the GC-MS analysis. The organism records during the Holocene were reconstructed in this region. The regular variation between the dominant C25 and C31 n-alkanes concentration in the peat core reveal that the peat swamp possibly occur the replacement of the morphologically-based species or the chemically-based species during the Holocene. This replacement might be the result of climatic change. When the climate fluctuates largely, the swamp possibly appears the replacement between aquatic plants and the terrestrial plants; On the contrary, when the climate has a small variation, the chemically-based species will present replacement. The results are compared with pollen records in the same region. The discrepancy between the n-alkanes and pollen records was analyzed. One of reason is the n-alkanes mainly record the composition of plant debris deposited locally, the pollen assemblage is more an average signal of the flora over a wider area. The results give a new proof for the biology information of the Holocene in the Qinghai-Xizang Plateau. The author also proposes lipid biomarkers (such as n-alkanes) can be viewed as the effective tool of vegetation reconstruction, together with the pollen, and will gain the detailed vegetation evolution history.更多还原