Measurement of the Exchange Rate of Greenhouse Gases between Field and Atmosphere in Semi Arid Grassland
半干旱草原地-气温室气体交换速率测定

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(50cm3 or 100cm3 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 CH4,CO2 and N2O 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 N2O,CO2 and CH4 from Aneurolepidium Chinese grassland and meadow steppe in the Inner Mongolia showed that this method was convenient and reliable.