Abstract

This chapter discusses the two respiration parameters, including O2 and CO2. A new technique based on cavity‐enhanced Raman multi‐gas spectrometry (CERS) that claims to have the potential to measure both O2 consumption and CO2 production on large closed systems which is a great leap forward in respiration studies, especially for the measurement of respiratory quotient (RQ). The chapter explains treatment of the O2/CO2 paradigm, there are many situations where the amount of CO2 produced during respiration is similar to the amount of O2 consumed. Furthermore, the chapter describes the plant carbon balance resulting from contributions from photosynthesis, photorespiration and respiration. The eddy co‐variance (EC) method allows estimations to be made of the net global carbon balance through the assessment of CO2, water and temperature fluxes under a broad range of both temporal and spatial scales.