Litterfall and leaf litter decomposition in a central African tropical mountain forest and Eucalyptus plantation

•Litter quality is a major determinant of decomposition.•Mixed-species litter can give a negative and positive additive effect.•Stand type effect was observed for the forest litter mixture only.•Nutrient depletion can occur in long-term in Eucalyptus plantation.•Final decay rate is also essential to explain the remaining mass.