The symposium is addressed to experimentalists and modellers working on land surface fluxes at the local to regional scale over land. The programme is open to a wide range of new studies in this field. It includes the development of new devices, measurement techniques and experimental design methods, as well as surface layer theory and parametrization at the local scale. The theoretical parts encompass models of the SVAT type, internal boundary layer theories and footprint analysis. Of special interest are comparisons of experimental data, parametrizations and models. This includes measurements of energy and trace gas fluxes (inert and reactive) as well as carbon dioxide fluxes. Specific focus is given to outstanding problems in land surface boundary layer descriptions such as complex terrain, energy balance closure, stable stratification and night time fluxes, as well as to the dynamical interactions with atmosphere, plants (in canopy and above canopy) and soils including the scale problems in atmosphere and soil exchange processes. Papers of the former session AS4.10/BG2.18 "Boreal forest chemistry and physics" are included.