农垦与放牧对内蒙古草原N_2O、CO_2排放和CH_4吸收的影响  

Effects of Grazing and Cultivating on Emission of Nitrous Oxide, Carbon Dioxide and Uptake of Methane from Grasslands

作　　者：王跃思[1] 纪宝明[2] 黄耀[1] 胡玉琼[1] 王艳芬[2] 

机构地区：[1]中国科学院大气物理研究所大气边界层物理和大气化学国家重点实验室北京,100083 [2]中国科学院植物研究所,北京100093

出　　处：《环境科学》2001年第6期7-13,共7页Environmental Science

基　　金：国家自然科学基金资助项目 (496 75 2 70 ;49790 0 2 0 ) ;中科院"引进国外杰出人才"基金资助项目

摘　　要：利用优选静态箱 /气相色谱法 (GC) ,首次对我国内蒙古草原典型地区进行了人类活动对N2 O、CO2 和CH4交换通量影响的实验观测 .结果表明 ,农垦麦田N2 O平均排放通量比原始草原高出 3倍 ,并改变了草甸草原为CO2 汇的性质 ,使其季节排放净通量以C计增加 1 4 .3mg·(m2 ·h) - 1.随放牧强度的增加CO2 排放通量呈线性增长 ,轻牧会引起草原对CH4 吸收的大幅增加 ,而随着放牧压力的增大 ,增加值迅速回落 .农垦麦田与草甸草原相比地 气间CH4 交换无显著变化 ,放牧强度对N2 O排放影响无显著规律 .土壤湿度和温度是影响草原排放N2 O和CO2 、吸收CH4 季节变化形式的关键因子 ,而人类活动仅影响排放强度 .排放和吸收量年际间差异很大 ,但主要受降水的影响 .N2 O和CO2 排放与CH4Measurement of N 2O, CO 2 and CH 4 with the optimized closed chamber/GC technique in the typical grassland, which were influenced by human activities, grazing and cultivating first time in situ were carried out in Inner Mongolia of P. R. China from 1998 to 1999. It was found that wheat cropping can increase N 2O production 3 times than the native, and changed a CO 2 sink of Inner Mongolia Steppe to a significant source, increased efflux CO 2 (C)average 14.3 mg·(m 2 ·h) -1 from Jun. to Dec. in 1998. CH 4 uptake was highly increased if there was grazing lightly. There were no effects of wheat cropping on CH 4 uptake and no significant results of grazing on N 2O emission. Soil moisture and temperature were the key factors ,other than human activities, which affect the patterns of seasonal variation of N 2O and CO 2 emission and CH 4 uptake. Highly inter annual variations,which resulted from the annual precipitation, of the exchange fluxes and seasonal variation patterns of N 2O and CO 2 emission and CH 4 uptake there were. It was a fact that N 2O and CO 2 emission from the soils was inversely related to CH 4 uptake.

关 键 词：内蒙古草原 N2O CO2 CH4 农垦 放牧 草原 温室气体 大气环境 废气排放 

分 类 号：X511[环境科学与工程—环境工程]