半干旱草原地-气温室气体交换速率测定

Measurement of the Exchange Rate of Greenhouse Gases between Field and Atmosphere in Semi Arid Grassland *

重点介绍采用静态箱 -气相色谱法测定低交换速率的半干旱草原地 -气间温室气体交换速率的采样分析系统的配置及操作 .将静态采样箱置于采样点 ,用 50 cm3或 1 0 0 cm3的塑料注射器现场取样 ,转存于气袋中并送到实验室分析 .用改进了的进样系统并装有 FID和 ECD的气相色谱仪 ( GC)分析其中的 CH4、CO2 和 N2 O浓度 ,计算出地 -气痕量温室气体的交换速率 .对内蒙古羊草草原、草甸草原 N2 O、CO2 和 CH4交换速率日变化规律实测结果分析表明 ,该方法简便易行、准确可靠 .

The method composed of static chamber and GC was used to measure the exchange rates of trace greenhouse gases between field and atmosphere in temperate semi arid grassland.This paper mainly introduced the configuration and operation of the sampling and analysing systems.Plastic syringes(50cm 3 or 100cm 3 volume)were used to pump gas samples from the closed chambers which were in situ.Gas samples were saved in syringes or gas sampling bags,and then were transported to the center lab.GC/FID & GC/ECD with the modified system of the samples injection were used to analyses the concentration of CH 4,CO 2 and N 2O in the gas samples.The exchange rates of those trace greenhouse gases between field and atmosphere were calculated at last.The results based on the in situ measurement of the diurnal variation of the exchange rates of the N 2O,CO 2 and CH 4 from Aneurolepidium Chinese grassland and meadow steppe in the Inner Mongolia showed that this method was convenient and reliable.