The soil/atmosphere flux of many trace gases have been measured by soil chamber techniques while micrometeorological methods have been less generally used. Micrometeorological methods are conceptually ideal for measuring trace gas emissions over large ecologically uniform areas. This is because the general techniques, eddy correlation and flux-radient, require large uniform terrain to function correctly. The techniques have not been extensively used to measure N2O and CH4 flux, however, because analytical methods that respond rapidly enough or are sensitive enough to quantify these gases were not available. Soil chamber methods have been used to measure fluxes of these gases and such studies generally infer that these measurements represent the larger area from the which the samples were taken. As development of sensitive, fast response chemical detectors permit, eddy correlation flux measurement will undoubtly complement chamber methods to measure trace gas flux. This paper provides a brief, simple description of techniques that have been or could be used to measure trace gas flux from terrestrial ecosystems. Three examples of how different techniques have been used to measure the flux of N2O or CH4 from very different but relatively uniform terrestrial ecosystems to the atmosphere are presented.
