Canopy conductance

Dimensionless quantity

Canopy conductance, commonly denoted $g_{c}$ {\displaystyle g_{c}}, is a dimensionless quantity characterizing radiation distribution in tree canopy. By definition, it is calculated as a ratio of daily water use to daily mean vapor pressure deficit (VPD).^[1] Canopy conductance can be also experimentally obtained by measuring sap flow and environmental variables.^[2] Stomatal conductance may be used as a reference value to validate the data, by summing the total stomatal conductance $g_{s}$ {\displaystyle g_{s}} of all leaf classes within the canopy.^[3]

$g_{c}=\sum _{layer_{1}}^{layer_{N}}(g_{s,sun}^{i}\cdot l_{sun}^{i})+(g_{s,shade}\cdot l_{shade})$ {\displaystyle g_{c}=\sum _{layer_{1}}^{layer_{N}}(g_{s,sun}^{i}\cdot l_{sun}^{i})+(g_{s,shade}\cdot l_{shade})}