Black pine plantations in Carst have lost their vitality and have become a fire hazard, therefore they will have to be substituted with more appropriate deciduous trees in order to preserve the forests and perhaps in time even raise their value. The aim of this thesis is to present the presence of selected deciduous trees with which Carst has been once afforested and to explain the ecologic circumstances that affect their growing. The possibilities of future growing of the following deciduous trees are studied: common beech (Fagus sylvatica L.), sessile oak (Quercus petraea (matt.) Liebl.), nettle tree (Celtis australis L.), cammon walnut (Juglans regia L.), wild cherry (Prunus avium L.) and sycamore (Acer pseudoplatanus L.).