首页> 中文期刊> 《湖泊科学》 >1860年以来博斯腾湖碳沉积过程演变

1860年以来博斯腾湖碳沉积过程演变

         

摘要

Despite the small coverage on the earth, lakes play an important role in the terrestrial carbon cycle. There are a large number of lakes in Xinjiang, Northwest China, where remarkable climate changes and human activity have been undergone over the past decades. Lake Bosten, the largest fresh water inland lake in Northwest China, was selected as the study site. We designed to investigate the temporal variability of carbon burial over the past 150 years, by examining the chronology and multi-proxies (i. e.magnetic susceptibility, grain size, organic carbon, inorganic carbon and stable carbon isotopes) of lacustrine sediments in Lake Bosten. The process variations of sedimentary carbon accumulation in Lake Bosten were divided into five stages since 1860. Before1910 s, environmental changes were mainly affected by the natural factors, with relatively lower sediment accumulation rates and total organic carbon (TOC), and a stable total inorganic carbon (TIC) in the eastern lake area but a downward trend in the northwest part. During 1910s-1950 s, the sediment accumulation rates in the western lake was much higher than that in the eastern deep area, characterized with low lake primary productivity and allochthonous dominated organic carbon (OC). During 1950s-1980 s, a rapid increase trend was found for both TOC and TIC, especially in the northwest lake section near the Huangshui River, while OC from allochthonous showed a decrease. The sediment accumulation rate increased significantly in all the three cores in the 1980s-2002 s, a similar trend shown in TOC under a warm climate. After 2002 s, the sediment accumulation rate was relatively high, but the contribution from allochthonous sources was small. During the last 150 years, the carbon accumulation rates presented an increasing trend, especially since 1960, with higher values in the eastern lake area than in the western section.%选取博斯腾湖3个不同点位岩芯, 在210Pb和137Cs年代序列基础上, 利用沉积物中的各理化指标, 分析了该湖碳沉积的时空变化特征, 结合各指标的相关性、沉积速率、C/N、同位素特征等, 探讨了该湖1860年以来碳沉积环境的变化过程, 为干旱区湖泊碳埋藏研究提供了依据.结果表明:1860-1910年, 沉积速率相对较小, 受人类活动影响较小, 磁化率、中值粒径、总无机碳 (TIC) 较为稳定, 总有机碳 (TOC) 含量相对较低, 此时该湖有较多陆源有机质的输入; 1910-1950年, 湖泊西部浅水域沉积速率明显高于东部深水区, 西北湖区水域有大量外源物质的输入, 而湖泊初级生产力较低, 内源贡献相对较小; 1950-1980年, 全湖TOC、TIC含量均呈现升高的趋势, 尤其是西北近黄水沟水域升高最快, 湖泊内源贡献在增加, 陆源组分的输入相对前一阶段要少; 1980-2002年, 沉积速率快速升高, 尤其湖泊东部水域最为明显, TOC含量均呈现升高的趋势, 湖泊西部水域初级生产力要高于东部深水区, 湖面蒸发较强, 气候比较温暖; 2002年以来, 全湖沉积速率相对较高, 外源有机质贡献较小.过去150年博斯腾湖沉积物碳累积速率整体上呈现出升高的趋势, 尤其是近50年来快速升高, 东部湖区碳累积速率比西部湖区高.

著录项

  • 来源
    《湖泊科学》 |2019年第1期|293-304|共12页
  • 作者单位

    中国空间技术研究院钱学森空间技术实验室, 北京 100094;

    北京师范大学全球变化与地球系统科学研究院, 北京 100875;

    中国科学院新疆生态与地理研究所荒漠与绿洲国家重点实验室, 乌鲁木齐 830011;

    环境保护部南京环境科学研究所, 南京 210042;

    中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室, 南京 210008;

    首都师范大学资源环境与旅游学院, 北京 100048;

  • 原文格式 PDF
  • 正文语种 chi
  • 中图分类
  • 关键词

    博斯腾湖; 有机碳; 无机碳; 沉积速率; 碳沉积过程;

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