Pedosphere 14(2): 195--204, 2004
ISSN 1002-0160/CN 32-1315/P
©2004 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Plateau marsh methane oxidation as affected by inorganic N |
WANG Zhi-Ping 1,2, DUAN Yi2, YANG Ju-Rong3, LI Ling-Hao1 and HAN Xing-Guo1 |
1 Laboratory of Quantitative Vegetation Ecology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093 (China). E-mail: wangzp5@yahoo.com;
2 State Key Laboratory of Gas Geochemistry, Lanzhou Institute of Geology, Chinese Academy of Sciences, Lanzhou 730000 (China);
3 College of Resource and Environment, Beijing Normal University, Beijing 100875 (China) |
| ABSTRACT |
| In a series of laboratory incubations using soils of two contrasting sites from a temperate marsh on the Qinghai-Tibet Plateau, potential methane (CH4) oxidation rates were measured to study the effects of inorganic N inputs on CH4 oxidation. For a drained site, subsurface peat (5-15 cm) at an initial 20 μL CH4 L-1 showed a significantly different (P < 0.05) CH4 oxidation rate compared to other soil depths, with a maximal rate of 20.9 ng CH4 gDW (dry weight)-1 h-1; the underlying mineral soil layers (15-30 and 30-50 cm) also had a strong CH4 oxidation capacity at about an initial 2000 μL CH4 L-1. With a waterlogged site, the CH4 oxidation rate in an aerobic incubation was significantly greater (P < 0.05) in the surface soil layer (0-5 cm) compared to the 15-30 and 30-50 cm depths. There was generally no or a very weak effect from addition of NO3- on CH4 oxidation. In marked contrast, NH4+ salts, such as (NH4)2SO4, NH4Cl and NH4NO3, exhibited strong inhibitions, which varied as a function of the added salts and the initial CH4 level. Increasing NH4+ usually resulted in greater inhibition and increasing initial CH4 concentrations resulted in less. NH4+ inhibition on CH4 oxidation in natural high-altitude, low-latitude wetlands could be as important as has been reported for agricultural and forest soils. The NH4+ effects on the CH4 oxidation rate need to be further investigated in a wide range of natural wetland soil types. |
| Key Words: ammonium, inhibition, inorganic N, methane oxidation, plateau marsh |
| Citation: Wang, Z. P., Duan, Y., Yang, J. R., Li, L. H. and Han, X. G. 2004. Plateau marsh methane oxidation as affected by inorganic N. Pedosphere. 14(2): 195-204. |
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