The results of a modelling approach are used to assess the sensitivity of the L-band backscattering coefficient to forest parameters. Vertical backscatter profiles were generated and point out that the main scatterers change as a function of growth stage and polarization. The link between the backscattering coefficient and the density and diameter of the main scatterers was assessed. Correlation through allometric equations with stand density and basal area and thus with bole volume, explained the polarization behaviour of the backscatter sensitivity to stem volume.