Specific mountain environmental conditions and mountain vegetation above the climatic treeline offer an opportunity to use plant species for studying the climate change impact. Conclusions drawn from climatic impacts assessment resulted into consequences important to plant population genetics, ecophysiology, phenology, phytogeography and vegetation dynamics. General species distribution (persistence, fragmentation shifts), potential responses of vegetation (area border and compositional shifts) and mutual interactions are mentioned as important consequences of global changes. Hence plant communities should be considered as dynamic, long-living and resilient entities formed and controlled by global climate.