Genetic potential for N2O emissions from the sediment of a free water surface constructed wetland
Genetic potential for N2O emissions from the sediment of a free water surface constructed wetland
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DOI：
10.1016/j.watres.2011.08.025
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发表时间：
2011-11-01
期刊：
影响因子：
12.8
通讯作者：
Baneras, Lluis
中科院分区：
文献类型：
--
作者：
Garcia-Lledo, Arantzazu;Vilar-Sanz, Ariadna;Baneras, Lluis
氮的去除是人工湿地功能的一个关键方面。然而，不完全的反硝化可能导致温室气体一氧化二氮（N2 O）的净排放，从而对本应提供生态系统服务的系统造成不期望的影响。在这项工作中，我们评估了N2 O排放量的遗传潜力的存在或不存在的芦苇和香蒲在自由水面人工湿地（FWS-CW），因为植被，通过增加有机物由于凋落物降解，可能会显着影响种植区的反硝化能力。实时荧光定量PCR分析的基因在反硝化途径指示能力，产生或减少N2 O进行了在不同的水排放的时期。从所有反硝化基因和一氧化二氮还原酶编码基因（nosZ）的相对丰度估计N2 O排放的遗传潜力。nosZ丰度总是低于其他的分解基因（低至100倍），差异显着增加期间的高硝酸盐负荷的CW表明一个更高的遗传潜力的N2 O排放。这种情况与处理池中较低的脱氮效率相吻合。植被的存在和类型，主要是由于沉积物中的碳和氮含量的变化，负相关的硝酸盐和亚硝酸盐还原剂之间的比例和正相关的亚硝酸盐和一氧化二氮还原剂之间的比例。这些结果表明，潜在的一氧化二氮的排放量较高的植被沉积物。(C)2011爱思唯尔有限公司保留所有权利。
Removal of nitrogen is a key aspect in the functioning of constructed wetlands. However, incomplete denitrification may result in the net emission of the greenhouse gas nitrous oxide (N2O) resulting in an undesired effect of a system supposed to provide an ecosystem service. In this work we evaluated the genetic potential for N2O emissions in relation to the presence or absence of Phragmites and Typha in a free water surface constructed wetland (FWS-CW), since vegetation, through the increase in organic matter due to litter degradation, may significantly affect the denitrification capacity in planted areas. Quantitative real-time PCR analyses of genes in the denitrification pathway indicating capacity to produce or reduce N2O were conducted at periods of different water discharge. Genetic potential for N2O emissions was estimated from the relative abundances of all denitrification genes and nitrous oxide reductase encoding genes (nosZ). nosZ abundance was invariably lower than the other denitrifying genes (down to 100 fold), and differences increased significantly during periods of high nitrate loads in the CW suggesting a higher genetic potential for N2O emissions. This situation coincided with lower nitrogen removal efficiencies in the treatment cell. The presence and the type of vegetation, mainly due to changes in the sediment carbon and nitrogen content, correlated negatively to the ratio between nitrate and nitrite reducers and positively to the ratio between nitrite and nitrous oxide reducers. These results suggest that the potential for nitrous oxide emissions is higher in vegetated sediments. (C) 2011 Elsevier Ltd. All rights reserved.