Plantations may contribute to biodiversity restoration through facilitation of indigenous forest succession in their understory, by enhancing tree seedling species diversity and abundance. To assess long term dynamics in such plantations, we tested the initial floristic composition hypothesis, which proposes a sequential floristic or life form dominance of species. For forests, the succession starts with early successional species, comprising light demanding, disturbance tolerant or generalist species. Gradually, these species are replaced by late successional species, including shade tolerant, climax or specialist species. The tree regeneration under circa 50 year old plantations of five exotic species (Acacia, Grevillea, Eucalyptus, Pinus and Cupressus) was compared to generation in both small, disturbed and large, intact afromontane cloud forest fragments. In all plantation types, an increase in biodiversity and abundance of indigenous species was observed from the mature tree layer to the seedling layer. However, the dissimilarity between indigenous forest fragments and plantations remained high, even in the sapling and seedling layer, mainly because of the dominance of early successional species in the regeneration. Arrested succession results in a disequilibrium between the regenerating species pool and the tree species pool at the landscape scale, which means that these plantations are marked by a high colonization credit. A low structural complexity of plantations, comprising low horizontal and vertical heterogeneity, undeveloped soil organic layer or impeded inter specific facilitation, permits a lower number of establishment sites than indigenous forests with a heterogeneous complexity. In addition, tree harvest coupled with dead wood and fire have unfavourable effects on the recruitment of indigenous forest vegetation. Therefore, to stimulate further indigenous forest restoration of the plantations, it is essential to improve the structural quality after which enrichment planting can be considered. ; status: published