Here we introduce a revised formulation for the flux-gradient relationships which incorporates these coherent structures. The associated predictions for the profiles of mean wind speed, temperature and water vapour mixing ratio agree with observations across a range of canopies and diabatic stabilities. By including the revised relationships within a simple coupled energy balance for a canopy and the boundary layer above it, we investigate the impact of the relationships on the diurnal evolution of the canopy and boundary layer states. We will show that the revised relationships can lead to a significantly different diurnal evolution of the energy balance and boundary layer, particularly in the partitioning between sensible and latent heat fluxes (the Bowen ratio) during the day time. We also highlight some implications of this work for the formulation of surface exchange schemes (for canopies) within more complex numerical weather prediction models.