Effect of land-use change on CH4 and N2O emissions from freshwater marsh in Northeast China
Effect of land-use change on CH4 and N2O emissions from freshwater marsh in Northeast China
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DOI：
10.1016/j.atmosenv.2009.04.020
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发表时间：
2009-07-01
影响因子：
5
通讯作者：
Song, Changchun
中科院分区：
文献类型：
--
作者：
Jiang, Changsheng;Wang, Yuesi;Song, Changchun
湿地在全球碳和氮储存中发挥着重要作用，同时也是甲烷（CH 4）和一氧化二氮（N2 O）等温室气体的天然来源。土地利用变化是影响湿地与大气之间温室气体交换的一个重要因素。然而，很少有研究探讨土地利用变化对中国淡水沼泽CH 4和N2 O排放的影响。为此，在东北三江平原3个样点（小叶章沼泽、旱地和稻田）进行了为期一年的野外调查，研究了CH 4和N2 O排放的季节变化。沼泽地是CH 4的来源，表现出明显的时间变化。最大通量出现在6月份，最高值为20.69 +/- 2.57 mg CH 4 m（-2）h（-1）。沼泽湿地N_2O排放通量季节变化不明显，由一系列的排放脉冲组成。湿地在冬季是N2 O的汇，在生长季则是N2 O的源。结果表明，冬季土壤/雪与大气之间的气体交换对年度收支贡献很大。冬季CH 4排放量约占全年排放量的3.24%，冬季N2 O吸收量占生长季排放量的13.70%。将沼泽地改为旱地导致从强CH 4源转变为弱汇（从199.12 +/- 39.04千克CH 4公顷（-1）年（-1）变为-1.37 +/- 0.68千克CH 4公顷（-1）年（-1）），同时N2 O排放量略有增加（从4.07 +/-1.72千克N2 O公顷（-1）年（-1）变为4.90 +/- 1.52千克N2 O公顷（-1）年）。沼泽地改为水稻地使CH 4排放量从199.12 +/- 39.04降至94.82 +/- 9.86 kg CH 4 ha（-1）yr（-1），N2 O排放量从4.07 +/- 1.72降至2.09 +/- 0.79 kg N2 O ha（-1）yr（-1）。(C)2009爱思唯尔有限公司保留所有权利。
The wetlands play an important role in global carbon and nitrogen storage, and they are also natural sources of greenhouse gases such as methane (CH4) and nitrous oxide (N2O). Land-use change is an important factor affecting the exchange of greenhouse gases between wetlands and the atmosphere. However, few studies have investigated the effect of land-Use change on CH4 and N2O emissions from freshwater marsh in China. Therefore, a field Study was carried out over a year to investigate the seasonal changes of the emissions of CH4 and N2O at three sites (Deyeuxia angustifolia marsh, dryland and rice field) in the Sanjiang Plain of Northeast China. Marsh was the source of CH4 Showing a distinct temporal variation. Maximum fluxes occurred in June and the highest value was 20.69 +/- 2.57 mg CH4 m(-2) h(-1). The seasonal change of N2O fluxes from marsh was not obvious, consisted of a Series of emission Pulses. The marsh acted as a N2O sink during winter, while became a N2O source in the growing season. The results showed that gas exchange between soil/snow and the atmosphere in the winter season contributed greatly to the annual budgets. The winter season CH4 flux was about 3.24% of the annual flux and the winter uptake of N2O accounted for 13.70% of the growing-season emission. Conversion marsh to dryland resulted in a shift from a strong CH4 source to a weak sink (from 199.12 +/- 39.04 to -1.37 +/- 0.68 kg CH4 ha(-1) yr(-1)), while increased N2O emissions somewhat(from 4.07 +/- 1.72 to 4.90 +/- 1.52 kg N2O ha(-1) yr(-1)). Conversion marsh to rice held significantly decreased CH4 emission from 199.12 +/- 39.04 to 94.82 +/- 9.86 kg CH4 ha(-1) yr(-1) and N2O emission from 4.07 +/- 1.72 to 2.09 +/- 0.79 kg N2O ha(-1) yr(-1). (C) 2009 Elsevier Ltd. All rights reserved.