Journal of Plant Ecology ›› 2023, Vol. 16 ›› Issue (1): 0-.DOI: 10.1093/jpe/rtac037

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  • 收稿日期:2021-11-03 修回日期:2021-12-04 接受日期:2022-01-23 出版日期:2023-02-01 发布日期:2023-01-29

Spectroscopic properties and driving factors of dissolved organic matter in the Yellow River Delta

Yuan Cui1, Fang-Li Luo1,2,*, Ming-Xiang Zhang1,2 and Fei-Hai Yu3,*   

  1. 1 School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China, 2 The Key Laboratory of Ecological Protection in the Yellow River Basin of National Forestry and Grassland Administration, Beijing 100083, China, 3 Institute of Wetland Ecology & Clone Ecology, Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou 318000, China

    *Corresponding author. E-mail: ecoluofangli@bjfu.edu.cn (F.-L. L); feihaiyu@126.com (F.-H. Y)
  • Received:2021-11-03 Revised:2021-12-04 Accepted:2022-01-23 Online:2023-02-01 Published:2023-01-29

摘要: 黄河三角洲溶解有机质的光谱特征及其驱动因素
河口三角洲是生物地球化学循环的热点地区。了解该区域溶解有机质(DOM)的来源及其驱动因素对于评估其在调节全球碳通量中的作用具有重要意义。本研究分析了黄河三角洲淡水和潮汐区域中土壤DOM的光谱特征。通过平行因子分析(PAFARAC),以及与在线数据库(http://www.openfluor.org)的对比最终确定了5种荧光组分(包括2种类腐殖酸、2种类蛋白质和1种可能的污染物)。淡水和潮汐区域中土壤DOM及各荧光组分的浓度、光谱性质和来源均不同。潮汐区DOM的浓度较低,而相对分子质量较高。在淡水地区,土壤DOM主要来源于浮游植物和微生物;而在潮汐地区,土壤DOM主要来源于微生物和人类活动。这两个地区土壤DOM的差异主要由环境因素驱动,尤其是土壤碳(C)、氮(N)及其化学计量比C/N,能够解释DOM和CDOM变化的80.7%和69.6%。此外,浮游植物也对该地区土壤中的DOM、CDOM和荧光组分(C1–C4)有重要的影响,结果发现它们之间存在显著的正相关关系。研究结果表明,黄河三角洲土壤DOM的浓度和组成受土壤性质和浮游植物密度的强烈驱动。


关键词: 溶解有机质, 河口湿地, 淡水湿地, 光谱特征, 潮汐湿地

Abstract:

River deltas are hot spots of biogeochemical cycling. Understanding sources and driving factors of dissolved organic matter (DOM) in river deltas is important for evaluating the role of river deltas in regulating global carbon flux. In this study, spectroscopic properties of soil DOM were analyzed in both freshwater and tidal areas of the Yellow River Delta. Five fluorescent components of soil DOM (two humic-like DOM, two protein-like DOM and one possible contaminant) were identified by parallel factor analysis and further confirmed by comparison with an online database. Concentration, spectroscopic properties and sources of soil DOM and its components differed between freshwater and tidal areas. DOM concentration was much higher in freshwater areas than in tidal areas. In freshwater areas, soil DOM was mainly derived from phytoplankton and microorganisms, while it was mainly derived from microorganisms and human activities in tidal areas. These differences in DOM between both areas were strongly driven by environmental factors, especially soil carbon (C), nitrogen (N) and its stoichiometric ratio C/N. These explained 80.7% and 69.6% of variations in DOM and chromophoric DOM (CDOM), respectively. In addition, phytoplankton also contributed to soil DOM, CDOM and fluorescent components C1–C4 as identified by significant positive correlations between them. These results imply that both the concentration and composition of soil DOM are strongly driven by soil properties and phytoplankton density in the Yellow River Delta.

Key words: dissolved organic matter, estuary wetland, freshwater wetlands, spectroscopic property, tidal wetlands