This seminar surveys some of the contributions in the field of land-surface atmosphere interactions from the author and her group. The seminar focuses on flux measurements in realistic, non-idealized field conditions where micrometeorological theory breaks down. Some of the difficult conditions encountered by the experimentalist measuring the exchange of gases between the atmosphere and the surface include non-homogeneous patchy terrain and in nocturnal conditions.  These aspects are discussed in the light of the fact that atmospheric circulations and/or mesoscale contributions can surreptitiously creep into local surface fluxes, masking the true local gaseous exchange.  The need for extreme vigilance in the interpretation of the lower boundary-layer gaseous exchange measurements is emphasized and recommendations made to help the experimentalist. The work presented shows a combination of atmospheric measurements and modeling.