Methods for stable gas flux determination in aquatic and terrestrial systems

Publisher Summary This chapter discusses the methods for stable gas flux determination in aquatic and terrestrial systems. The primary considerations in the choice of method for measuring gas fluxes include the type of ecosystem under study, the cost, infrastructure and logistic support, the gas species in question, and the availability of precise analytical instruments having appropriate response rates for measuring gas fluxes. Fluxes of trace gases from terrestrial systems have been measured by enclosure or micrometeorological techniques. Because of the enclosure and limited spatial resolution of the closed-chamber method, it was found suitable for detecting small fluxes of trace gases, studying the processes, and identifying the sources of spatial variations controlling gas fluxes. Micrometeorological methods provide nondestructive, integrated measurements of gas fluxes over large areas but generally require a large, uniform fetch. Tower-based and airborne eddy-flux correlation methods require expensive fast-response sensors and logistic support. The exchange of nonreactive trace gases among water, soil, and atmosphere are regulated by the same chemical, biological, and physical parameters.