Soil seed bank characteristics in two central African forest types and implications for forest restoration

•Soil seed bank characteristics depends on rainforest types (vegetation and soil).•Deep soil layers (up to 20 cm depth) have important seed stocks.•Each soil layer, including the 10–20 cm stratum, display exclusive taxa.•Similarity between pioneers of the soil seed bank and tree stand reaches 39–47%.•Timber tree taxa are lowly represented in the seed banks.