Trends in plant population pattern changes under natural and man-induced ecosystem transformations of the high mountain zone in the Ukrainian Carpathians

A substantial increase of area, numbers and density in populations of trees, shrubs and dwarf shrubs – Picea abies, Pinus mugo, Alnus viridis, Juniperus sibirica, Vaccinium-species is marked in the high-mountain zone of the Ukrainian Carpathians. The flowering and fruit maturation at higher elevations of alpine belt are characteristic for the number of species of different life forms: Vaccinium myrtillus, Centaurea mollis, Homogyne alpina, Helictotrichon versicolor, Potentilla aurea. This trend is related to warming and prolongation of growing season and it is peculiar for the species with ecological and climate optima in the forest and subalpine belts, whereas the conditions of the alpine belt are extreme for them. The expanding populations of rare and endemic plant species: Loiseleuria procumbens, Senecio carpaticus, Heracleum carpaticum, Rhododendron myrtifolium, Callianthemum coriandrifolium, Galium pawlowskii have been found. However, the alpine and arctic-alpine species: Oreochloa disticha, Rhodiola rosea, Carex curvula etc. demonstrate negative dynamics.The described processes are mainly the result of successions and plant cover restoration due to grazing termination and climate warming. The impact of plant cover restoration and raising of the timberline on populations of investigated species at high mountain zone of protected areas often cannot be separated from the impact of global warming