• 论文 •

### 内蒙古温带半干旱羊草草原N2O通量及其影响因素

1. 1. 中国科学院地理科学与资源研究所 北京100101;
2. Department of Geography,Mainz University,Mainz55099,Germany
• 收稿日期:2004-07-12 修回日期:2004-09-25 出版日期:2004-12-15 发布日期:2004-12-15
• 作者简介:董云社(1961-),男,陕西武功人,研究员,博导,博士。主要从事全球变化与温室气体排放以及碳、 氮元素生物地球化学循环等方面的实验研究,已发表论文60余篇。E-mail:dongys@igsnrr.ac.cn.
• 基金资助:

中国科学院知识创新重大项目(KZCX1SW0104);中国科学院地理科学与资源研究所知识创新项目(CXIOGE010301);国家重点基础研究发展规划目(2002CB412503)资助

### The N2O fluxes in Leymus Chinense grassland of Inner Mongolia, China

DONG Yun-she1, QI Yu-chun1, Manfred Domroes2, GENG Yuan-bo1, YANG Xiao-hong1, LIU Li-xin1, LIU Xing-ren1

1. 1. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China;
2. Department of Geography, Mainz University, Mainz 55099, Germany
• Received:2004-07-12 Revised:2004-09-25 Online:2004-12-15 Published:2004-12-15

Abstract:

Using the static chamber method, the fluxes of nitrous oxide from the undisturbed community and soil layer were measured through the continuous experiment in situ from 2001 to 2003 in Leymus Chinense grassland in Xilin river basin of Inner Mongolia, China.The seasonal variation, characteristics of sources and sinks, and the effects of main environmental factors on N 2O fluxes were analyzed. The regression models between the N 2O fluxes and the environmental factors were also established using the statistical method, at the same time, the annual total emission flux of N 2O was estimated. The main results are as follows:(1) The seasonal variations of N 2O fluxes in undisturbed community and soil layer were very obvious with higher emissions in spring and summer, then autumn but maintaining a relatively low emissions level in winter, furthermore, negative fluxes were found sometimes in winter. (2) The annual mean N 2O flux of undisturbed community ranged from 3.91 μgm -2h -1 to 4.71 μgm -2h -1 and that of soil layer ranged from 5.49 to 10.03 μgm -2h -1.The average N 2O flux of undisturbed community was lower than that of soil layer in the same statistical period, the relative thick litter layer obviously reduced the emission of N 2O to a certain degree. (3) To compare the N 2O fluxes of the whole year, the N 2O fluxes from undisturbed community and soil layer were significantly positive correlated with the air temperature and surface soil temperature at non-growing season, whereas they had a weak correlation with the soil moisture. The changes of air temperature and the other closely relative temperature factors could account for 72%～88% of the variation of undisturbed community and soil layer N 2O fluxes in non-growing season. What’s more, the correlations between N 2O flux and the soil temperature at 5cm and 10cm depth were higher than that between N 2O flux and surface soil temperature. But in growing season, negative correlations were found between N 2O flux and the air temperature and the soil temperature at 0cm, 5cm and 10cm depth, especially the correlations between N 2O flux and air temperature reached the significance level of 0.05. The results of multi-variable stepwise regression indicated that the change of 0～10cm and 10～20cm soil moisture could account for 72～85% of the variation of undisturbed community and soil layer N 2O fluxes in growing season.