Theory 05/Peclet Number/Root nutrient uptake
Uptake Depends on a Peclet
The claim
Nutrient capture by roots is set by the Peclet number at the root surface, so transpiration rate changes uptake efficiency non-monotonically.
01Mechanism
Water flow carries nutrients to the root while diffusion supplies them from the bulk soil; the balance sets whether supply keeps up with demand.
02Prediction
Uptake should peak at an intermediate Peclet.
03Refutation
Uptake increasing monotonically with flow would remove the balance.