The SMOS mission, planned for launch in 2007, will carry an L-band (1.4 GHz) multi-angle, dual-polarisation interferometric microwave radiometer for global monitoring of soil moisture (and ocean salinity). For routine processing of global scale SMOS soil moisture data, the τ-ω zero-order transfer model has been selected. However, at a global scale, a high percentage of SMOS pixels is infected with fractional forest, whereas for most forest types the radiative transfer properties at L-band are practically unknown. This paper presents some preliminary results of the Bray'04 experimental campaign, which was held with the objective of studying the angular and polarisation characteristics of a coniferous forest, as knowledge of the effects of forests on the microwave signal is essential for solving the problem of heterogeneity. The main focus of these results is parameter retrieval of the single scattering albedo (ω), the effective dielectric constant (κ) of the emitting surface layer and the vegetation optical depth (τ).