Plateau Marsh Methane Oxidation as affected by Inorganic N  

作　　者：WANGZhi-Ping DUANYi YANGJu-Rong LILing-Hao HANXing-Guo 

机构地区：[1]LaboratoryofQuantitativeVegetationEcology,InstituteofBotany,ChineseAcademyofSciences,Beijing100093（China）／E-mail：[e-mail] [2]StateKeyLaboratoryofGasGeochemistry,LanzhouInstituteofGeology.ChineseAcademyofSciences,Lanzhou730000（China） [3]CollegeofResourceandEnvironment,BEijingNormailUniversity,Beijing100875（China）

出　　处：《Pedosphere》2004年第2期195-204,共10页土壤圈（英文版）

基　　金：Project supported by the Knowledge Innovation Project in Resource and Environment Fields, Chinese Academy of Sciences (No. KZCX3-SW-128), the Open Foundation of the State Key Laboratory of Gas Geochemistry (SJJ-01-07), and the National Key Basic Research

摘　　要：In a series of laboratory incubations using soils of two contrasting sitesfrom a temperate marsh on the Qinghai-Tibet Plateau, potential methane (CH_4) oxidation rates weremeasured to study the effects of inorganic N inputs on CH_4 oxidation. For adrained site, subsurfacepeat (5--15 cm) at an initial 20 mu L CH_4 L^(-1) showed a significantly different (P < 0.05) CH_4oxidation rate compared to other soil depths, with a maximal rate of 20.9 ng CH_4 gDW (dryweight)^(-1) h^(-1); the underlying mineral soil layers (15--30 and 30--50 cm) also had a strongCH_4 oxidation capacity at about an initial 2 000 mu L CH_4 L^(-1). With a waterlogged site, theCH_4 oxidation rate in an aerobic incubation was significantly greater (P < 0 05) in the surfacesoil layer (0--5 cm) compared to the 15--30 and 30--50 cm depths. There was generally no or a veryweak effect from addition of NO_3^- on CH_4 oxidation. In marked contrast, NH_4^+ salts, such as(NH_4)_2SO_4, NH_4Cl and NH_4NO_3, exhibited strong inhibitions, which varied as a function of theadded salts and the initial CH_4 level Increasing NH_4^+ usually resulted in greater inhibition andincreasing initial CH_4 concentrations resulted in less NH_4^+ inhibition on CH4 oxidation innatural high-altitude, low-latitude wetlands could be as important as has been reported foragricultural and forest soils. The NH_4^+ effects on the CH_4 oxidation rate need to be furtherinvestigated in a wide range of natural wetland soil types.In a series of laboratory incubations using soils of two contrasting sites from a temperate marsh on the QinghaiTibet 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)-1h-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 (0-5cm) 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,NH4C1 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.

关 键 词：AMMONIUM INHIBITION inorganic N methane oxidation plateau marsh 

分 类 号：S153.6[农业科学—土壤学]