Linacre’s Simple Model for Water Loss in a Leaf

Linacre (1964) shows that humidity and wind speed affect transpiration and cooling in a leaf. Specifically, cooling of a leaf increases because of dry and calm air. Transpiration is the water passing through the leaf surface to the air. Linacre sets up a relatively simple model for rate of water loss in a leaf growing from wet soil. To start, three equations are given, which are developed.

R = LE + H    (1)

H = (Ts – Ta) / rx    (2)

LE = (es – ea) / (ri + re)    (3)

Eq. (1) gives the radiation to the air, Eq. (2) is for heat flux from the air and Eq. (3) is proportional to the water loss rate.