By using the micrometeorological Eddy covariance technique, which is based on the measurement of turbulent exchanges, the predominant type of transport between the surface and the near atmosphere, these exchanges are quantified. In addition, supported by other techniques, such as IRGA camera systems (at soil, plant and leaf scales) and other complementary measurements of atmospheric and soil state, we discriminate the processes involved in these exchanges and the main ecosystem elements responsible for these fluxes.