The dissertation is devoted to the complex analysis of the viability of Pinus pallasiana D. Don and P. sylvestris L. on three iron ore dumps in Kryvyi Rih Area. The object of the study is artificial plantations and introducing populations of Pinus pallasiana and P. sylvestris. Methods of research – field observations (stationary and expeditionary), laboratory research, dendrological, morphometric, comparative-morphological, methods of population biology and genetics, statistical with using applied computer programs. We ascertained that 35-40-year-old plantations of Pinus pallasiana and P. sylvestris on the dumps of Kryvyi Rih Area are characterized by high stability and life expectancy; they can successfully grow and develop in different plots of dumps, which differ significantly in mechanical and physical-chemical composition of substrates. In the 30-35-year-old plantations of P. pallasiana and P. sylvestris, as a result of fall of needles and cones, as well as the natural fall of the lower branches, the stable litter forms, in the lower layer of which detritus forms. Plants of both species of pines that have reached the reproductive phase of development, on the dumps form a superficial root system with well-developed horizontal lateral roots. Formation of such a root system that goes far beyond the projection of the crown is an adaptive response of plants to a specific edaphic environment, since in the surface layer of the substrate, due to physical and chemical weathering, more nutrients, which are available to plants, are accumulated. The phenomenon of seed renewing of both species of pines on iron ore dumps is noted annually around their primary plantations within a radius of 300–500 m. Young self-seeded plants form the first female cones at 7 years of age and in subsequent years they have normal reproductive capacity, forming a full-fledged seed. The spatial placement of microsites of self-seeding is determined by the directions of prevailing winds, the physical-chemical composition of substrates, and the peculiarities of micro- and mesorelief of dumps. Particular populations of loci in the dumps have an area of 1–2 hectares, and the density of young plants in them reaches 15–75 individuals of different ages per 100 m2. The area of natural establishment of P. pallasiana around the parent plantings is 0.043–1.0 hectares; that is 2.4–21.5 times larger than the area of these parent plantings. The largest number of microsites of self-seeding in the dump are occupied by 3-, 4- and 7-year-old plants, and the smallest one – by 2- and 10-year-old ones. The vast majority of self-seeded plants of P. pallasiana on an iron-ore dump is characterized by a high level of vitality and in the age of 7–10 years; their morphometric indicators predominate the self-seeding on the post-fire plots in the natural population of this species in the Mountain Crimea. The local populations of P. pallasiana and P. sylvestris, spontaneously formed on iron ore dumps of Kryvyi Rih Area, have slightly reduced level of allelic diversity, but in terms of heterozygosity, they are inferior to the natural populations of these species in the Mountain Crimea and the Steppe, respectively. We developed the methodical approach for monitoring the forest suitability of the dump as a whole and its individual parts for biological reclamation, with the exception of the materially and financially costly technical stage of redevelopment of its surface and the filling of the soil layer. We patented some methods of using P. pallasiana and P. sylvestris in greening of iron ore dumps in Kryvyi Rih Area.
