华东师范大学学报(自然科学版) ›› 2022, Vol. 2022 ›› Issue (3): 101-108.doi: 10.3969/j.issn.1000-5641.2022.03.011

• 河口海岸学 • 上一篇    

长江口沉积物固氮过程的温度敏感性及影响因素

游智湧, 刘博林, 刘程, 高灯州*()   

  1. 华东师范大学 河口海岸学国家重点实验室, 上海 200241
  • 收稿日期:2021-01-11 接受日期:2021-01-11 出版日期:2022-05-25 发布日期:2022-05-19
  • 通讯作者: 高灯州 E-mail:dzgao@sklec.ecnu.edu.cn
  • 基金资助:
    国家重点研发计划 (2016YFA0600904)

Temperature sensitivity and controlling factors of nitrogen fixation processes in sediments of the Yangtze River Estuary

Zhiyong YOU, Bolin LIU, Cheng LIU, Dengzhou GAO*()   

  1. State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200241, China
  • Received:2021-01-11 Accepted:2021-01-11 Online:2022-05-25 Published:2022-05-19
  • Contact: Dengzhou GAO E-mail:dzgao@sklec.ecnu.edu.cn

摘要:

探讨微生物固氮过程的温度敏感性对认识全球气候变化背景下河口近岸生态系统的稳定及氮素平衡具有重要意义. 然而, 到目前为止, 关于河口沉积物固氮过程对温度变化的响应及影响因素的研究还鲜见报道. 本文选取长江口6个采样站位 (包括长江口内4个和长江口外2个) , 采用泥浆培养实验, 并结合15N同位素示踪技术对长江口沉积物固氮过程的温度敏感性及影响因子展开研究. 结果表明, 长江口沉积物中原位温度的固氮速率范围是0.72 ~ 2.85 nmol·g–1·h–1. 在5 ~ 10 ℃和20 ~ 30 ℃培养条件下, 温度升高对固氮速率具有一定的抑制作用, 而在10 ~ 20 ℃的培养条件下, 温度升高对固氮速率有明显的促进作用. 尽管各站点沉积物理化性质相差较大, 但固氮速率对温度的敏感性相对一致. 相关性分析结果表明, 硫化物、二价铁、硝态氮和总有机碳含量是影响固氮作用的主要环境因子.

关键词: 固氮过程, 温度敏感性, 同位素示踪, 沉积物, 长江口

Abstract:

To understand the stability of the estuarine ecosystem and nitrogen balance in the context of global climate change, it is important to investigate the temperature sensitivity of the microbial nitrogen fixation process. Until now, there have been few studies in the literature on the response of the nitrogen fixation process to temperature changes and its influencing factors. We selected six sampling sites around the Yangtze River Estuary (including four sites inside and two sites outside the Yangtze River Estuary) for the scope of the study; in particular, we explored the temperature sensitivity and influencing factors of the nitrogen fixation process on sediments of the Yangtze River Estuary using slurry incubation experiments and the 15N2 isotope tracer technique. The results showed that the in-situ temperature nitrogen fixation rate in the sediments of the Yangtze River Estuary ranged from 0.72 to 2.85 nmol·g–1·h–1. At 5 ~ 10 ℃ and20 ~ 30 ℃, the nitrogen fixation rate was inhibited by an increase in temperature. However, in the range of 10 ~ 20 ℃, the nitrogen fixation rate was significantly promoted with an increase in temperature. The sensitivity of the nitrogen fixation rate to temperature is relatively consistent, although the physical and chemical properties of the sediments vary significantly. Correlation analysis showed that the contents of sulfide, ferrous iron, nitrate, and total organic carbon were the main environmental factors affecting nitrogen fixation.

Key words: nitrogen fixation, temperature sensitivity, isotope-tracing techniques, sediment, the Yangtze River Estuary

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