Wind Profiles in Plant Canopies: Studies on an Analytical Model

calculated, using a one-dimensional model, in terms of the vertical profiles of the concentration, and the transfer coefficients (K m2 s- 1). Transfer coefficients can be obtained either from energy balance or aerodynamic measurements-in both cases the assumption of equality between the transfer coefficients of the various entities is usually made. (In this paper Krefers to the momentum transfer coefficient, also called the eddy viscosity.) A pre-requisite of any attempt to derive the momentum transfer coefficient is an accurate knowledge of the wind profile in the plant-air layer. Wind speeds should also be incorporated in any model which purports to make layer-by-layer estimates of photosynthesis in plant stands, since the ventilation at any level is an important factor in the transfer processes between leaves and their immediate environment.