Integrating fluxes from heterogeneous vegetation

The vegetated landscape of Europe has been strongly impacted by human management to produce a heterogeneous patchwork of semi‐natural and agricultural vegetation varying over a wide range of spatial scales. A model is described for averaging vegetation fluxes from a landscape of forest and grassland into the planetary boundary layer (PBL). At a scale of 1 km, model simulations indicate that vegetation heterogeneity exerts little effect on the PBL and regional fluxes will be simple areal averages of the different vegetation types. Above 5 km the model simulates significant effects of different vegetation types on the whole PBL. Averaging fluxes to the regional scale will therefore need to consider explicitly the nature, extent and behaviour of different vegetation types.