This article proposes a method to predict the scattered signal inside and around a tree trunk formation. The method presented here is based on an empirical model that characterizes the re-radiation patterns of both dielectric and metallic cylinders for three spot frequencies, 9.4, 18.8 and 37.6 GHz and, resorting to dRET (discrete Radiative Energy Transfer) model to gather all the interaction between trunks within a formation, the received signal can be predicted. Presented empirical model was developed based on both dielectric and metallic re-radiation pattern measurements in an anechoic chamber and it is used as an input parameter of dRET model, characterising the trunk cells. This paper also contemplates measurements within a tree trunk formation in order to assess the values extracted from dRET model.