The Slovak forest ecosystems will be influenced by several aspects of global changes - changes of atmospheric temperature and precipitation, increase of the CO2 concentrations, extreme meteorological events etc. The analysis of the bioclimatic conditions changes for main forest communities (GCMs and analogue scenarios) has shown that climate in the future will create the most favourable conditions for oak communities (55 - 88 % from presently afforested area), the worse for coniferous communities (spruce 0,5 - 4 %, fir 1,5 - 7,5 %). Also the dynamic models (Gap models) documented significant changes in the tree species and bioproduction dynamics in relation to the altitude. The life cycle of the natural virgin forests would be in the range 200 - 400 years, the rotation period in the managed forests would be about 100 years. Therefore the strategy in Slovak forestry must be based on anticipatory adaptation measures; otherwise the reactive measures will not be effective.