The biomass allocation, as well as leaf and short root morphological parameters in young (1-7-year-old) black alder (Alnus glutinosa (L.) Gaertn), silver birch (Betula pendula Roth.) and Scots pine (Pinus sylvestris L.) plantations on the oil shale post-mining area were investigated with the aim to analyze morphological adaptations of studied parameters in relation to tree species and stand age. The adaptive strategies of tree species in young plantations on the reclaimed stony and alkaline mining area were different. Scots pine allocated more biomass into leaves and fine roots while black alder and silver birch into stems and coarse roots. The black alder leaves were heavier and with larger area, but thinner than those of silver birch. Different strategies of short root morphological adaptations were observed in coniferous and deciduous tree species on the oil shale post-mining area. Deciduous species were found to have higher short root specific root area and specific root length values, and lower short root tissue density and diameter values compared to coniferous species such as Scots pine. An extensive building of the fine root system was inherent to Scots pine, whereas deciduous trees improved mineral nutrition more by morphological adaptations of fine roots.