Release of nitrous oxide and dinitrogen from a transition bog under drained and rewetted conditions due to denitrification: results from a [15N]nitrate–bromide double-tracer study
Release of nitrous oxide and dinitrogen from a transition bog under drained and rewetted conditions due to denitrification: results from a [15N]nitrate–bromide double-tracer study
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DOI：
10.1080/10256016.2015.1011634
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发表时间：
2015-02
影响因子：
1.3
通讯作者：
Nadine Tauchnitz;O. Spott;R. Russow;S. Bernsdorf;B. Glaser;R. Meissner
中科院分区：
文献类型：
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作者：
Nadine Tauchnitz;O. Spott;R. Russow;S. Bernsdorf;B. Glaser;R. Meissner
众所周知，反硝化作用是在积水泥炭土壤中最重要的硝酸盐消耗过程，由此最终释放中间化合物一氧化二氮（N2 O）和最终产物二氮（N2）。本研究的目的是评估这些气体的释放（由于反硝化作用）从营养贫乏的过渡沼泽生态系统排水和三种不同的再润湿条件下，在现场规模使用15 N示踪剂的方法（[15 N]硝酸盐的应用，30公斤氮公顷−1）和一个共同的封闭室技术。排水部位的特征在于恒定水位（WT）为-30 cm（此处称为D30），而再润湿部位分别表示恒定WT为-15 cm、恒定WT为0 cm（即，浸水）和初始WT为0 cm（其在实验期间略微降低）（此处分别称为R15、R 0和R 0 d）。在D30（291 µg N2 O-N m−2 h−1）和R 0 d（665 µg N2 O-N m −2 h −1）观测到最高的N2 O排放量。在WT恒定的再湿润泥炭地（即R15和R 0），观察到的N2 O排放量要低得多（最大值为37 µg N2 O-N m−2 h−1）。对于N2，仅在最初的泥炭地R 0 d中观察到相当大的释放速率（高达3110 µg N2-N m-2 h-1），而在排水条件下（D30）没有N2排放，在WT恒定的再湿润条件下（R15和R 0）可以检测到显著较低的N2释放速率（最大668 µg N2-N m-2 h-1）。此外，人们已经发现，自然WT波动在再润湿泥炭网站，特别是快速下降的WT，可以诱导高排放率的N2 O和N2。
Denitrification is well known being the most important nitrate-consuming process in water-logged peat soils, whereby the intermediate compound nitrous oxide (N2O) and the end product dinitrogen (N2) are ultimately released. The present study was aimed at evaluating the release of these gases (due to denitrification) from a nutrient-poor transition bog ecosystem under drained and three differently rewetted conditions at the field scale using a 15N-tracer approach ([15N]nitrate application, 30 kg N ha−1) and a common closed-chamber technique. The drained site is characterized by a constant water table (WT) of –30 cm (here referred to as D30), while rewetted sites represent a constant WT of –15 cm, a constant WT of 0 cm (i.e. waterlogged), and an initial WT of 0 cm (which decreased slightly during the experiment), respectively, (here referred to as R15, R0, and R0d, respectively). The highest N2O emissions were observed at D30 (291 µg N2O–N m−2 h−1) as well as at R0d (665 µg N2O–N m−2 h−1). At the rewetted peat sites with a constant WT (i.e. R15 and R0), considerably lower N2O emissions were observed (maximal 37 µg N2O–N m−2 h−1). Concerning N2 only at the initially water-logged peat site R0d considerable release rates (up to 3110 µg N2–N m−2 h−1) were observed, while under drained conditions (D30) no N2 emission and under rewetted conditions with a constant WT (R15 and R0) significantly lower N2 release rates (maximal 668 µg N2–N m–2 h−1) could be detected. In addition, it has been found that natural WT fluctuations at rewetted peat sites, in particular a rapid drop down of the WT, can induce high emission rates for both N2O and N2.