| 引用本文: | 卢沛琪,薛刚,郑艳红.察汗淖尔表层沉积物GDGTs分布特征及影响因素.湖泊科学,2024,36(2):467-476. DOI:10.18307/2024.0224 |
| Lu Peiqi,Xue Gang,Zheng Yanhong.Distributions of GDGTs and its influencing factors in surface sediments of Lake Chahannaoer. J. Lake Sci.2024,36(2):467-476. DOI:10.18307/2024.0224 |
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| 摘要: |
| 目前,甘油二烷基甘油四醚(GDGTs)组成和分布特征已被成功应用于古气候古环境重建中。然而,越来越多的研究表明除温度和pH值外,GDGTs也受其他环境因素影响,这导致了在同一地区运用多种温度和pH校准公式得到的结果差异较大,特别是在干旱地区尤为显著。因此,有必要开展现代过程GDGTs分布及其影响因素的调查,以提高温度和pH校准公式的适用性。为此,我们以北方察汗淖尔湖泊为中心,分析流域内24个湖泊沉积物和土壤GDGTs组成和分布。结果显示,所有样品GDGTs分布模式相似,其中古菌类异戊二烯GDGTs(简称isoGDGTs)以crenarchaeol为主,GDGT-0次之,crenarchaeol'含量较低,指示GroupⅠ.1b型奇古菌输入较多;细菌支链GDGTs(简称brGDGTs)中五甲基化brGDGTs丰度最高,其次是六甲基化和四甲基化brGDGTs。群落指数(community index,CI)表明, 产brGDGTs的细菌群落属于冷簇,且冗余分析显示pH值对brGDGTs分布影响显著,二者可能共同导致了应用多种校准公式计算结果与器测记录之间的差异。通过该项工作我们认为在利用GDGTs重建古气候时应开展GDGTs现代过程调查,明确环境主导因素,并选择合适的区域校正公式以获取准确的气候信息。 |
| 关键词: GDGTs 察汗淖尔 分布特征 湖泊沉积物 表层土壤 |
| DOI：10.18307/2024.0224 |
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| 基金项目:国家自然科学基金项目(41872031)和陕西省杰出青年基金项目(2018JC-021)联合资助。 |
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| Distributions of GDGTs and its influencing factors in surface sediments of Lake Chahannaoer |
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Lu Peiqi, Xue Gang, Zheng Yanhong
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State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an 710069, P.R. China
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| Abstract: |
| The glycerol dialkyl glycerol tetraethers (GDGTs)-based indices are increasingly used to reconstruct the paleoclimate and paleoenvironment. However, the distribution of GDGTs is controlled by both climatic and complex environmental factors, which causes significant difference in the results obtained by using multiple temperature and pH calibration formulas in the same region, especially in arid areas. Here we analyzed the composition and distribution of GDGTs in surface sediments and soils of Lake Chahannaoer. Our results indicated that isoprenoid GDGTs (isoGDGTs) were dominated by crenarchaeol and GDGT-0, and branched GDGTs (brGDGTs) were dominated by the pentamethylated brGDGTs (IIa and IIa'). The community index (CI) indicated that the brGDGTs-producing bacterial community fell within clusters cold, and redundancy analysis (RDA) showed that pH was thought to be the major influencing factor for the distributions of brGDGTs in Lake Chahannaoer. The two factors might lead to differences between the reconstruction results of various climate calibration formulas and the instrumental records. Through this work, we argue that the investigation on GDGTs' modern process should be carried out to establish a suitable climate correction formula to obtain accurate paleoclimate information. |
| Key words: GDGTs Lake Chahannaoer distributions characteristics lake sediment surface soil |
