Is surface conductance theoretically independent of reference height?

Many studies have compared surface conductance G s at different observation sites when examining physiological differences between sites and/or between vegetation categories. However, a theoretical analysis confirming the robustness of such comparisons has not yet been published. It is unclear whether G s is independent of the reference height where evaporative fluxes and meteorological factors are observed, as G s is a conceptual parameter rather than a purely physiological parameter. This short note shows that G s is independent of reference height when above‐canopy fluxes of evapotranspiration and available energy are independent of reference height, and when energy balance closure is complete. Thus, this note gives a theoretical basis for comparing G s values at different observation sites. Furthermore, we make recommendations for examining the G s dependency on reference height in field conditions. Copyright © 2005 John Wiley & Sons, Ltd.