State Environment Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun 130024, China.
School of Environment, Northeast Normal University, Changchun 130024, China.
Sci Rep. 2017 Jan 18;7:40848. doi: 10.1038/srep40848.
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 (NO) 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 NO 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 CO production confimed DAMO did occur in both the paddy-peatland and the undisturbed peatland, the rates of which increased with NO additions, but decreased logarithmically with time. When NO was added, there were no significant differences between the CH oxidation in the paddy-peatland and peatland samples after 36 hours of incubation (97.08 vs. 143.69 nmol g dry peat) and the potential DAMO rate after incubation for 1 hour (92.53 vs. 69.99 nmol gh). These results indicate that the occurrence of DAMO in peatlands might be controlled by the amount of NO applied and the depth to which it penetrates into the anoxic layer.
泥炭地富含有机物但氮素有限，其碳氮（C/N）状况受到长期硝酸盐（NO）肥料投入和大气氮（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中依赖反硝化的甲烷厌氧氧化（DAMO）。在这项研究中，我们使用稳定同位素测量和添加 NO 的培养来促进对经过 40 多年氮肥影响的稻田泥炭地和中国东北未受干扰的泥炭地中潜在 DAMO 速率的调查和比较。CO 生成的监测证实 DAMO 确实发生在稻田泥炭地和未受干扰的泥炭地中，其速率随 NO 添加而增加，但随时间呈对数下降。当添加 NO 时，经过 36 小时培养后，稻田泥炭地和泥炭地样品中的 CH 氧化（97.08 与 143.69 nmol g 干泥炭）和培养 1 小时后的潜在 DAMO 速率（92.53 与 69.99 nmol gh）之间没有显著差异。这些结果表明，泥炭地中 DAMO 的发生可能受施加的 NO 量和其穿透缺氧层的深度控制。
