热带海洋学报

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稳定同位素示踪浙江清江口红树林沉积物氮源及其影响因子分析

谭清碧1, 郭泓瀛1, 孙思旗1, 钟宇航1, 聂会2, 牛丽霞1, 3, 4   

  1. 1. 中山大学 海洋工程与技术学院/南方海洋科学与工程广东省实验室, 广东 珠海 519000;

    2. 浙江水利水电学院, 浙江 杭州 310018;

    3. 河口海岸研究所/广东省海岸与岛礁工程技术研究中心, 广东 广州 519000;

    4. 广东省深水信息技术重点实验室, 广东 珠海 519000

  • 收稿日期:2025-08-06 修回日期:2025-10-06 接受日期:2025-10-17
  • 通讯作者: 牛丽霞
  • 基金资助:

    浙江省自然科学基金项目(LGEY25E090012), 浙江省水利厅科技计划项目(RC2436),国家自然科学基金(51709289)

Analysis of nitrogen source and influencing factors in mangrove sediments of the Qingjiang Estuary (Zhejiang) using stable isotopes

TAN Qingbi1, GUO Hongying1, SUN Siqi1, ZHONG Yuhang1, NIE Hui2, NIU Lixia1,3,4   

  1. 1. School of Ocean Engineering and Technology, Sun Yat-sen University(Guangzhou)/Southern Laboratory of Ocean Science and Engineering, Zhuhai 519000, China;

    2. Zhejiang Water Conservancy and Hydropower College, Hangzhou 310018, China;

    3. Institute of Estuarine and Coastal Research, Guangdong Provincial Engineering Research Center of Coasts, Islands and Reefs, Guangzhou 519000, China;

    4. Guangdong Provincial Key Laboratory of Information Technology for Deep Water Acoustics, Zhuhai 519000, China


  • Received:2025-08-06 Revised:2025-10-06 Accepted:2025-10-17

摘要: 乐清湾清江河口位于我国红树林分布的最北端, 处于温带与亚热带交汇的生态过渡地带, 研究开展红树林区域沉积物氮源分析,具有重要的生态参考价值。本文选取了清江口红树林(2019年及2020年种植)、互花米草、混合区等典型植被区域开展采样及分析, 通过分析沉积物中总氮(total nitrogen, TN)、总有机碳(total organic carbon, TOC)及总有机质(total organic matter, TOM)等指标, 并结合δ¹³C、δ¹⁵N稳定同位素特征及多源混合模型(Multi-source mixing model in R, MixSIAR), 识别氮和有机质的主要来源。结果表明, 清江河口沉积物氮、碳含量整体呈现由西向东递减趋势, 反映出陆源输入强度的空间梯度差异; 不同植被类型区域的氮形态及含量差异显著, 互花米草区由于植物根系活性较弱、生产力较低、有机质分解速率较快, 对外源有机质与氮素的截留能力有限, 红树林生态系统在调节氮循环方面的功能强于互花米草。氮源分析显示, 该区域主要以其它陆源输入为主, 占33.65%, 红树林(C₃植物)贡献率达到25.28%, 海洋来源贡献为23.78%, 互花米草(C₄植物)的影响相对较小, 为17.33%。本研究揭示了清江河口植被类型与氮的空间分布之间的关系, 探讨了红树林在区域氮循环过程中的关键生态功能, 为不同气候带红树林生态系统的保护修复与河口氮污染防控提供了理论依据和实践指导。

关键词: 清江河口, 沉积物, 稳定同位素, 红树林, 有机质

Abstract: The Qingjiang Estuary in Yueqing Bay is located at the northernmost limit of mangrove distribution in China, situated in an ecological transition zone between temperate and subtropical regions, and holds significant ecological reference value. Field sampling and analyses were conducted in typical vegetation zones including mangroves (planted in 2019 and 2020), Spartina alterniflora stands, and mixed vegetation areas. Key parameters including total nitrogen (TN), total organic carbon (TOC), and total organic matter (TOM) in sediments were analyzed. Combined with δ¹³C and δ¹⁵N stable isotope characteristics and a multi-source mixing model (MixSIAR in R), the major sources of nitrogen and organic matter were identified. The results showed that nitrogen and carbon contents in estuarine sediments exhibited an overall decreasing trend from west to east, reflecting spatial gradient differences in terrestrial input intensity. Nitrogen forms and concentrations varied significantly among different vegetation types. In S. alterniflora areas, weaker plant root activity, lower productivity, and faster organic matter decomposition rates resulted in limited retention capacity for exogenous organic matter and nitrogen. The mangrove ecosystem demonstrated stronger regulatory functions in nitrogen cycling compared to S. alterniflora. Nitrogen source analysis revealed that other terrestrial inputs were predominant, accounting for 33.65%, followed by mangroves (C₃ plants) contributing 25.28%, marine sources contributing 23.78%, and S. alterniflora (C₄ plants) having relatively minor influence at 17.33%. This study elucidates the relationship between vegetation types and spatial nitrogen distribution in the Qingjiang Estuary, and explores the key ecological functions of mangroves in regional nitrogen cycling processes. The findings provide theoretical basis and practical guidance for the protection and restoration of mangrove ecosystems across different climate zones and for nitrogen pollution control in estuarine environments.

Key words: Qingjiang estuary, Sediment, Stable isotopes, Mangrove, Total organic matter