Growth and Productivity of Non-Indigenous Woody Species in the Middle Urals

Climate warming has been recorded over the last decades. The air temperature in Yekaterinburg has been rising since the 1930s. Temperatures dropped sharply in 1940–1949, then rose sharply and fell again, especially in 1967–1968, when many large introduced species considered to be adapted died: Phellodendron amurense Rupr. and Pseudotsuga taxifolia (Lindl.) Britt. Due to the cyclical nature of weather conditions, it was necessary to assess the features of adaptation and state of the introduced plants in recent years. Snowless autumn and winter, temperatures above zero in early spring are unfavourable for many species, especially or conifers. Thus, in 2014 much snow fell on October 16 and melted in 2 weeks, temperatures below zero did not afford plants to prepare for the winter; in March 2015 the temperature rose up to +10 °C while the ground temperature was below zero for a long time. As a result of physiological dryness 100 % of specimens of variegated forms of northern white cedar Thuja occidentalis L. `Ellwangeriana Aurea`, `Ericoides` died. In other forms the leafage died to the snow cover level and recovered after abundant rains: `Aurea spicata`, `Gold Pearl`, `Golden Globe`, `Lutescens`, `Semperaurea` and `Wareana Lutescens`. Due to a steady increase in the sum of positive temperatures and reaching a certain age, many conifer species entered the fruiting stage and gave self-seeding: Pinus peuce Grieseb, Pinus strobus L., Picea canadensis (Mill.) Britt. et al., Picea pungens Engelm., Pseudotsuga taxifolia (Lindl.) Britt., and Abies sachalinensis (F. Schmidt) Mast. In the warmest year of 2016, the latter gave an abundant yield – red-brown cones with protruding seed scales; a strong wind dropped them all. They remained under the snow for the winter and did not crumble (probably, the fruits were unripe), so Abies sachalinensis was mistaken for Keteleeria fortunei (A. Murray bis) Carrière), which has cones that do not crumble. Unusual flowering was observed in Crataegus oxyacantha L. `Rosea Plena`, Mespilus germanica L., Syringa reflexa C.K.Schneid, Hamamelis virginiana L. With the rise in average annual temperatures, the number of years with abnormal weather conditions increased and the condition of some plants deteriorated. For citation: Semkina L.A., Tishkina E.A. Growth and Productivity of Non-Indigenous Woody Species in the Middle Urals. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 6, pp. 100–109. DOI: 10.37482/0536-1036-2021-6-100-109