Articles techniques et présentations

The assessment of forest soil respiration and its isotopic composition is one of the important issues for the carbon cycling modeling (greenhouse gas emission control) because it is often inaccurate. Soil respiration is a complex process, depending on the coupling of several phenomena, which is therefore highly sensitive to any disturbance. In this work, the dynamics of the transport of two isotopes of CO2 in a porous forest soil have been numerically studied, coupling diffusion with convection and considering a periodic pressure fluctuation at the soil surface. It is shown that atmospheric disturbances may affect significantly both the time evolution of global CO2 flux leaving the soil and the isotopic ratio, by an indirect effect of the induced air flow in the soil.