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应用生态学报 ›› 2022, Vol. 33 ›› Issue (9): 2441-2449.doi: 10.13287/j.1001-9332.202209.012

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大气CO2浓度缓增对稻田硝酸盐型甲烷厌氧氧化过程的影响

黄翯宸1, 金靖昊1, 沈李东1*, 田茂辉1, 刘心1, 杨王挺1, 胡正华2   

  1. 1南京信息工程大学生态系, 南京 210044;
    2南京信息工程大学应用气象学系, 南京 210044
  • 收稿日期:2021-11-26 接受日期:2022-07-05 出版日期:2022-09-15 发布日期:2023-03-15
  • 通讯作者: * E-mail: shenld@nuist.edu.cn
  • 作者简介:黄翯宸, 男, 2000年生, 本科生。主要从事土壤微生物研究。E-mail: huanghechen0055@163.com
  • 基金资助:
    江苏省自然科学基金项目(BK20190092)、国家自然科学基金项目(41977037)和江苏省大学生创新创业训练计划重点项目(202210300062Z)资助。

Effect of gradual increase of atmospheric CO2 concentration on nitrate-dependent anaerobic methane oxidation in paddy soils

HUANG He-chen1, JIN Jing-hao1, SHEN Li-dong1*, TIAN Mao-hui1, LIU Xin1, YANG Wang-ting1, HU Zheng-hua2   

  1. 1Department of Ecology, Nanjing University of Information Science and Technology, Nanjing 210044, China;
    2Department of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China
  • Received:2021-11-26 Accepted:2022-07-05 Online:2022-09-15 Published:2023-03-15

摘要: 硝酸盐型甲烷厌氧氧化(AOM)是控制稻田甲烷排放的一种新途径,大气CO2浓度升高会对稻田甲烷排放产生重要影响,但有关其对硝酸盐型AOM过程的影响知之甚少。本研究依托开顶式气室组成的CO2浓度自动调控平台,采用13CH4稳定性同位素示踪技术,从甲烷氧化活性、相关功能微生物Candidatus Methanoperedens nitroreducens (M. nitroreducens)-like古菌丰度与群落组成等方面,系统研究了稻田土壤中硝酸盐型AOM过程对大气CO2浓度缓增的响应。试验设置背景CO2浓度和CO2浓度缓增处理(背景CO2浓度基础上每年增加40 μL·L-1,直至增幅达160 μL·L-1)。结果表明: 稻田土壤硝酸盐型AOM速率为0.7~11.3 nmol CO2·g-1·d-1;定量PCR结果显示,M. nitroreducens-like古菌mcrA基因丰度为2.2×106~8.5×106 copies·g-1。与对照相比,CO2浓度缓增处理使土壤中硝酸盐型AOM速率和M. nitroreducens-like古菌mcrA基因丰度均有一定幅度提高,特别是在5~10 cm深度下两者均显著提高。CO2浓度缓增处理未显著改变M. nitroreducens-like古菌群落结构,但使其多样性显著降低。相关性分析表明,土壤有机碳含量可能是影响硝酸盐型AOM过程的重要因子。综上,大气CO2浓度缓增在一定程度上促进了硝酸盐型AOM反应,暗示在未来气候变化背景下其在控制稻田甲烷排放中具有积极作用。

关键词: 稻田, 硝酸盐型甲烷厌氧氧化, CO2浓度升高, 群落组成

Abstract: Nitrate-dependent anaerobic oxidation of methane (AOM) is a new pathway to reduce methane emissions from paddy ecosystems. The elevated atmospheric CO2 concentration can affect methane emissions from paddy ecosystems, but its impact on the process of nitrate-dependent AOM is poorly known. Based on the automatic CO2 control platform with open top chambers and the 13CH4 stable isotope experiments, the responses of the activity of nitrate-dependent AOM, abundance and community composition of Candidatus Methanoperedens nitroreducens (M. nitroreducens)-like archaea to the gradual increase of CO2 concentration were investigated in paddy fields. We set up two CO2 concentration treatments, including an ambient CO2 and a gradual increase of CO2(increase of 40 μL·L-1 per year above ambient CO2 concentration until 160 μL·L-1). The results showed the nitrate-dependent AOM rate of 0.7-11.3 nmol CO2·g-1·d-1 in the studied paddy fields, and quantitative PCR showed the abundance of M. nitroreducens-like archaeal mcrA genes of 2.2×106-8.5×106 copies·g-1. Compared to the ambient CO2 treatment, the slow elevated CO2 treatment enhanced the nitrate-dependent AOM rate and stimulated the abundance of M. nitroreducens-like archaea, particularly in 5-10 cm soil layer. The gradual increased CO2 concentration treatment did not change the community composition of M. nitroreducens-like archaea, but significantly decreased their diversity. The soil organic carbon content was an important factor influencing the nitrate-dependent AOM process. Overall, our results showed that the gradual increase of CO2 concentration could promote the nitrate-dependent AOM, suggesting its positive role in mitigating methane emissions from paddy ecosystems under future climate change.

Key words: paddy field, nitrate-dependent anaerobic oxidation of methane, rising CO2 concentration, community composition