Aldasoro Juan J., Aedo Carlos, Garmendia Félix Muñoz, Hoz Francisco Pando de la, Navarro Carmen (2004): Revision of Sorbus Subgenera Aria and Torminaria (Rosaceae-Maloideae). Systematic Botany Monographs, 69, 1- https://doi.org/10.2307/25027918Andivia Enrique, Márquez-García Belén, Vázquez-Piqué Javier, Córdoba Francisco, Fernández Manuel (2012): Autumn fertilization with nitrogen improves nutritional status, cold hardiness and the oxidative stress response of Holm oak (Quercus ilex ssp. ballota [Desf.] Samp) nursery seedlings. Trees, 26, 311-320 https://doi.org/10.1007/s00468-011-0593-3 Bandurska H., Płachta V., Woszczyk M. (2009): Seasonal patterns of free proline and carbohydrate levels in cherry laurel (Prunus laurocerasus) and ivy (Hederea helix) leaves and resistance to freezing and water deficit. Dendrobiology, 62: 3–9. Bednorz L., Kaźmierczak K., Kaczmarek L. (2012): Analyses of spatial structure and selected measures of growth of Sorbus torminalis in Forest District Jamy (northern Poland Dendrobiology, 67: 59–65.Bednorz Leszek, Myczko Łukasz, Kosiński Piotr (2015): An assessment of genetic diversity following natural regeneration of Sorbus torminalis in the Forest District of Jamy (northern Poland). Dendrobiology, 73, 111-116 https://doi.org/10.12657/denbio.073.011 Bigras F.J., Ryyppö A., Lindström A., Stattin E. (2001): Cold acclimation and deacclimation of shoots and roots of conifer seedlings. In: Bigras F.J., Colombo S.J. (eds): Conifer cold hardiness. Dordrecht-Boston, Kluwer Academic: 57–88.Campbell C. S., Evans R. C., Morgan D. R., Dickinson T. A., Arsenault M. P. (2007): Phylogeny of subtribe Pyrinae (formerly the Maloideae, Rosaceae): Limited resolution of a complex evolutionary history. Plant Systematics and Evolution, 266, 119-145 https://doi.org/10.1007/s00606-007-0545-yCharrier Guillaume, Ngao Jérôme, Saudreau Marc, Améglio Thierry (2015): Effects of environmental factors and management practices on microclimate, winter physiology, and frost resistance in trees. Frontiers in Plant Science, 6, - https://doi.org/10.3389/fpls.2015.00259 Dospekhov B.A. (1985): Methods of the field experiment. Moscow, Agropromizdat: 351. (in Russian) Dubovitskaya O.Yu., Pavlenkova G.A. (2015): The arboretum of the Russian Research Institute of Fruit Crop Breeding. Short guide. Orel, VNIISPK: 64. (in Russian) Gidrometeo (1972): Agroclimatic reference book for the Oryol region. Leningrad, Gidrometeoizdat: 96. (in Russian) Groffman P.M., Driscoll C.T., Fahey T.J., Hardy J.P., Fitzhugh R.D., Tierney G.L. (2001): Colder soils in a warmer world: A snow manipulation study in a northern hardwood forest ecosystem. Biogeochemistry, 56: 135–150. https://doi.org/10.1023/A:1013039830323Hawkins Bradford A., Rueda Marta, Rangel Thiago F., Field Richard, Diniz-Filho José Alexandre F., Linder Peter (2014): Community phylogenetics at the biogeographical scale: cold tolerance, niche conservatism and the structure of North American forests. Journal of Biogeography, 41, 23-38 https://doi.org/10.1111/jbi.12171Heredia-Guerrero Norberto, Oliet Juan A., Villar-Salvador Pedro, Benito Luis F., Peñuelas Juan L. (2014): Fertilization regime interacts with fall temperature in the nursery to determine the frost and drought tolerance of the Mediterranean oak Quercus ilex subsp. ballota. Forest Ecology and Management, 331, 50-59 https://doi.org/10.1016/j.foreco.2014.07.022Kreyling Juergen, Schmid Stephanie, Aas Gregor, Higgins Steven (2015): Cold tolerance of tree species is related to the climate of their native ranges. Journal of Biogeography, 42, 156-166 https://doi.org/10.1111/jbi.12411LARCHER Walter (2005): Climatic Constraints Drive the Evolution of Low Temperature Resistance in Woody Plants. Journal of Agricultural Meteorology, 61, 189-202 https://doi.org/10.2480/agrmet.61.189 Maděra P., Kohoutek M., Šenfeldr M., Řepka R. (2012): The population structure and regeneration of Sorbus torminalis in Hádecká planinka National Nature Reserve (Czech Republic. Dendrobiology, 68: 63–68. Nigmatianova S.E. (2011): Evaluation of decorativeness of Malus Mill. representatives of Orenburg. Bulletin of Orenburg State Agrarian University, 3: 298–301. (in Russian) Nigmatianova S.E., Mursalimova G.R. (2015): Vegetative reproduction of introduced species of ornamental apple trees in Orenburg. Pomiculture & Small Fruits Culture in Russia, 42: 338–341. (in Russian) Nigmatianova S.E., Mursalimova G.R. (2016): Optimization of timing of propagation of woody ornamental crops by cuttings which are promising for planting in the Southern Urals. Pomiculture & Small Fruits Culture in Russia, 46: 280–284. (in Russian) Ozherelieva Z.E., Pavlenkova G.A. (2011): Potential resistance of lilac varieties to low temperatures in autumn and winter. Contemporary horticulture, 1: 1–4. (in Russian) Ozherelieva Z.E., Krasova N.G., Galasheva A.M. (2013): Study of apple variety-rootstock combinations according to winter hardiness components. Contemporary horticulture, 4: 1–10. (in Russian)Ozherelieva Zoya, Sedov Evgeny (2017): Low Temperature Tolerance of Apple Cultivars of Different Ploidy at Different Times of the Winter. Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences., 71, 127-131 https://doi.org/10.1515/prolas-2017-0022Potter D., Eriksson T., Evans R. C., Oh S., Smedmark J. E. E., Morgan D. R., Kerr M., Robertson K. R., Arsenault M., Dickinson T. A., Campbell C. S. (2007): Phylogeny and classification of Rosaceae. Plant Systematics and Evolution, 266, 5-43 https://doi.org/10.1007/s00606-007-0539-9Schaberg Paul G, DeHayes Donald H, Hawley Gary J, Murakami Paula F, Strimbeck G Richard, McNulty Steven G (2002): Effects of chronic N fertilization on foliar membranes, cold tolerance, and carbon storage in montane red spruce. Canadian Journal of Forest Research, 32, 1351-1359 https://doi.org/10.1139/x02-059SCHABERG PAUL G., HENNON PAUL E., D'AMORE DAVID V., HAWLEY GARY J. (2008): Influence of simulated snow cover on the cold tolerance and freezing injury of yellow-cedar seedlings. Global Change Biology, 14, 1282-1293 https://doi.org/10.1111/j.1365-2486.2008.01577.xŠpíšek Zdeněk, Uherková Andrea, Svitok Marek, Vašut Radim J. (2018): Sorbus domestica L. at its northern Pannonian distribution limits: distribution of individuals, fruit shapes and dendrometric characteristics. Dendrobiology, 80, 37-47 https://doi.org/10.12657/denbio.080.004Taulavuori Kari, Taulavuori Erja, Sheppard Lucy J. (2014): Truths or myths, fact or fiction, setting the record straight concerning nitrogen effects on levels of frost hardiness. Environmental and Experimental Botany, 106, 132-137 https://doi.org/10.1016/j.envexpbot.2013.12.022Toca Andrei, Oliet Juan A, Villar-Salvador Pedro, Maroto Judit, Jacobs Douglass F (2018): Species ecology determines the role of nitrogen nutrition in the frost tolerance of pine seedlings. Tree Physiology, 38, 96-108 https://doi.org/10.1093/treephys/tpx165 Turina M.M. (2000): A mechanism of adaptation to damaging factors of a cold period of the year in fruit and berry crops. In: International Conference – Biological Potential of Orchard Crops and Ways of Its Realization, Moscow, 19–22 June 1999: 15–24. (in Russian) Turina M.M., Gogoleva G.A., Efimova N.V., Goloulina L.K., Morozova N.G., Echedy Y.Y., Volkov F.A., Arsentieva A.P., Matjash N.A. (2002): Determination of fruit and berry crop resistance to stressors of the cold season in the field and controlled conditions. Moscow, VSTISP: 120. (in Russian) Villar-Salvador P., Penuelas J. L., Jacobs D. F. (2013): Nitrogen nutrition and drought hardening exert opposite effects on the stress tolerance of Pinus pinea L. seedlings. Tree Physiology, 33, 221-232 https://doi.org/10.1093/treephys/tps133Willson Cynthia J., Jackson Robert B. (2006): Xylem cavitation caused by drought and freezing stress in four co-occurring Juniperus species. Physiologia Plantarum, 127, 374-382 https://doi.org/10.1111/j.1399-3054.2006.00644.x Zwiazek J.J., Renault S., Croser C., Hansen J., Beck E. (2001): Biochemical and biophysical changes in relation to cold hardiness. In: Bigras F.J., Colombo S.J. (eds): Conifer cold hardiness. Dordrecht-Boston, Kluwer Academic: 165–186.