Spontaneous natural regeneration under variable conditions on sandy soils and continental sand dunes were analysed in 5 locations in N.E. Belgium. The number of seedlings varies between 14.000 and 522.000/ha. The most prominent invading species are red oak, pedunculate oak and Scots pine. Two principal types of regeneration are recognized : homogeneous groups of oak or pine and mixtures, predominantly composed by the same species. Pioneers such as birch, willow, white poplar and wild black cherry do not play an important role. Social differentiation sets in quite early and is mainly provoked by age differences. Therefore early silvicultural intervention is advisable. The growth relationships between the species indicate that Scots pine is not in danger of spontaneous elemination by other species. Because of the density and variability of spontaneous forest regeneration, the conversion of pure pine stands into mixed forest, using group regeneration to this end, poses no real technical problems.
