Century coniferous introduced species of the State Dendrological Park Trostjanets of the NAS of Ukraine

Objective – to reveal wood plants of order Pinophyta which reached an age of 100 and more years, to determine their quantity, maximal age, morphometric indicators and current decorative state. Material and methods. Century trees of such species are revealed: Abies alba Mill., A. concolor Lindl. et Gord., Larix decidua Mill., Picea abies (L.) Karst., P. jesoensis (Ziebold & Zucc.) Fish. ex Carr., Pinus nigra Arn., P. peuce Griseb., P. sylvestris L., P. strobus L., Pseudotsuga mensiesii (Mirb.) Franko, Thuja occidentalis L., T. plicata D. Don and Tsuga canadensis Carr. The age of separate trees and their morphometric indexes are recorded in materials of botanical inventories of park plantings (1948–2017), in card files of park dendroflora and in park guides. Nevertheless in the modern plantings there are a lot of aged trees which age is authentically not established. Their approximate age determined by comparison of size of their diameters with average sizes of diameters of trunks of trees which age was recorded in materials of botanical inventories earlier. The common decorative effect century trees was determined by O.A. Kalinichenko’s technique [7]. Results. A portion of coniferous trees 100 years and older is 15 % (1877 specimens) of the total number of trees (11,912) of the species examined. In order of decreasing number of ancient trees, the species studied are the following: Pinus sylvestris (1035), Larix decidua (385), Picea abies (209), Thuja occidentalis (119), Pinus strobus (42), Thuja plicata (39), Pinus nigra (24), Abies alba (7), Tsuga canadensis (4), Picea jesoensis (2), Abies concolor (1), Pinus peuce (1), Pseudotsuga mensiesii (1). A comparatively small percentage of the ancient trees Picea abies (5.6 %), Thuja occidentalis (6.5 %) and Thuja plicata (4.4 %) of the total number of plantations is due to significant decrease in old trees during the abnormally high air temperature in the period 2010–2012. Conclusions. On the basis of the studies, the following maximum age of coniferous trees has been revealed: for Pinus sylvestris, P. strobus, Picea abies and Larix decidua – 155 years, for Thuja occidentalis, Pinus nigra, Abies alba, Tsuga canadensi and Picea jesoensis – 145, for Thuja plicata, Abies concolor, Pinus peuce and Pseudotsuga mensiesii – 135. This gives ground to assert that the life span of plants of these species under the conditions of Dendropark Trostjanets can exceed the maximum specified. Identified centuryold trees have different levels of general decorativeness – from 2 to 5 points scale of Kalinichenko