Misconceptions about the relation between plant growth and respiration

The relation between plant growth rate and respiration rate is readily derived from the overall chemical reaction for aerobic metabolism. The derived relation can be used to show that separation of respiration into growth (g) and maintenance (m) components is not a useful concept, g and m cannot be unambiguously measured or defined in terms of biochemical processes. Moreover, because growth yield calculations from biochemical pathway analysis, from biomass molecular composition, from biomass heat of combustion, and from biomass elemental composition have not included all of the energy costs for biosynthesis, they are not accurate measures of the carbon cost for plant growth. Improper definitions of growth-respiration relations are impeding the use of physiological properties for prediction of plant growth as a function of environmental variables.