The role of spatial averaging scale in leaf-to-canopy scaling of non-linear processes in homogeneous canopies

Canopy biophysical models require averaging fluxes over some spatial scale (sub-leaf, leaf, sub-crown, crown, whole-canopy, etc.). Choice of averaging scale can be important when modeling processes like stomatal conductance and photosynthesis that have a non-linear response to environmental variables such as light interception. The model results archived here were used to quantify errors in canopy-level flux simulations due to averaging scale choice. A detailed leaf-resolving model was used to simulate light interception for a series of homogeneous canopies with differing canopy structure. Radiation model parameters and non-linearity of the light response were also varied. Averaging over individual leaves and over various sub-leaf resolutions were compared with averaging approaches used in multi-layer and two-leaf canopy models.