Rapid N2O fluxes at high level of nitrate nitrogen addition during freeze-thaw events in boreal peatlands of Northeast China
Rapid N2O fluxes at high level of nitrate nitrogen addition during freeze-thaw events in boreal peatlands of Northeast China
复制标题
中国东北北方泥炭地冻融过程中高水平硝态氮添加下的快速 N2O 通量
DOI：
10.1016/j.atmosenv.2016.03.053
复制
发表时间：
2016-06-01
影响因子：
5
通讯作者：
Guo, Yuedong
中科院分区：
文献类型：
--
作者：
Cui, Qian;Song, Changchun;Guo, Yuedong
冻融事件和氮素有效性的增加可能会改变多年冻土泥炭地的氮素周转和一氧化二氮(N2O)排放。然而，在FT事件期间，N2O排放对不同N水平和添加的响应远不清楚。通过培养试验，研究了不同氮素添加水平(LN：0.07mgNg(-1)，HN：0.14mgNg(-1))和不同氮素添加形式(AC：氯化铵、NS：硝酸钠)对东北中国泥炭地在FT和非冻融条件下N2O排放的影响。结果表明，FT处理显著增加了N2O的排放，且峰值出现在解冻过程中。与AC处理相比，在FT条件下，NS处理显著增加了N2O排放量的累积，且在不同的NS水平上表现出显著差异。N2O排放量也与土壤NO3-浓度成正比，为反硝化提供硝酸盐。在FT过程中，硝态氮的加入是导致N2O暴发的主要原因，反硝化作用是主要过程。因此，这些结果表明，在FT事件期间，随着永久冻土泥炭地硝酸盐氮沉积的增加，N2O排放可能增加，这将导致全球气候变暖。(C)2016爱思唯尔有限公司。保留所有权利。
Freeze-thaw (FT) events and increasing nitrogen (N) availability may alter N turnover and nitrous oxide (N2O) emissions in permafrost peatlands. However, the responses of N2O emissions to different N levels and additions during FT events are far from clear. We conducted an incubation study to investigate the impacts of different N addition levels (LN: 0.07 mg N g(-1), HN: 0.14 mg N g(-1)) and N addition forms (AC: ammonium chloride, NS: sodium nitrate) on the emissions of N2O under FT and non-freeze-thaw (NFT) conditions in boreal peatlands of Northeast China. Results indicated that the FT condition significantly increased N2O emissions compared with the NFT condition and peaks occurred during thawing. Compared with AC treatments, NS treatments significantly elevated the accumulation of N2O emissions under the FT condition, exhibiting significant differences in different NS levels. N2O emissions were also positively dependent on soil NO3- concentrations to supply nitrate for denitrification. Nitrate-N addition was mainly responsible for the burst of N2O with denitrification as the main process during FT events. Therefore, these results suggest that N2O emissions potentially increase during FT events with increasing nitrate-N deposition in permafrost peatlands, which would contribute to global climate warming. (C) 2016 Elsevier Ltd. All rights reserved.