Using (13)C isotopes to explore denitrification-dependent anaerobic methane oxidation in a paddy-peatland.
Using (13)C isotopes to explore denitrification-dependent anaerobic methane oxidation in a paddy-peatland.
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DOI：
10.1038/srep40848
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发表时间：
2017-01-18
影响因子：
4.6
通讯作者：
Ren X
中科院分区：
文献类型：
--
作者：
Shi Y;Wang Z;He C;Zhang X;Sheng L;Ren X
泥炭地是有机质丰富但氮含量有限的自然系统，其碳/氮 (C/N) 状态受到长期硝酸盐 (NO3−) 肥料输入和大气氮 (N) 沉积的影响。为了管理和保护这些独特的环境，需要更好地了解泥炭地反硝化依赖性甲烷厌氧氧化（DAMO）。在本研究中，我们使用稳定同位素测量和添加 NO3− 的培养方法，对受氮肥影响 40 多年的水稻泥炭地和中国东北未受干扰的泥炭地的潜在 DAMO 率进行调查和比较。对 13CO2 产生的监测证实，稻田泥炭地和未受干扰的泥炭地中确实发生了 DAMO，其速率随着 NO3− 添加而增加，但随着时间呈对数下降。当添加NO3−时，稻田泥炭地和泥炭地样品中孵化36小时后的CH4氧化（97.08 vs. 143.69nmol g−1 干泥炭）和孵化1小时后的潜在DAMO率（92.53 vs. 69.99nmol g−1 h−1）之间没有显着差异。这些结果表明，泥炭地中 DAMO 的出现可能受到 NO3− 的施用量及其渗入缺氧层的深度的控制。
Peatlands are organic-matter-rich but nitrogen-limited natural systems, the carbon/nitrogen (C/N) status of which are subject to increasing exposure from long-term nitrate (NO3−) fertilizer inputs and atmospheric nitrogen (N) deposits. To manage and protect these unique environments, an improved understanding of denitrification-dependent anaerobic oxidation of methane (DAMO) in peatlands is needed. In this study, we used stable isotope measurements and incubation with NO3− additions to facilitate an investigation and comparison of the potential DAMO rates in a paddy-peatland that has been influenced by N fertilizer over 40 years and an undisturbed peatland in northeast China. Monitoring of 13CO2 production confimed DAMO did occur in both the paddy-peatland and the undisturbed peatland, the rates of which increased with NO3− additions, but decreased logarithmically with time. When NO3− was added, there were no significant differences between the CH4 oxidation in the paddy-peatland and peatland samples after 36 hours of incubation (97.08 vs. 143.69 nmol g−1 dry peat) and the potential DAMO rate after incubation for 1 hour (92.53 vs. 69.99 nmol g−1 h−1). These results indicate that the occurrence of DAMO in peatlands might be controlled by the amount of NO3− applied and the depth to which it penetrates into the anoxic layer.