Retrospective analysis of the introduction of Pseudotsuga menziesii (Mirb.) Franco to predict the effectiveness of its use in the Lower Volga region

Abstract

On the basis of data on biological and silvicultural features of Pseudotsuga menziesii (Mirb.) Franco, a forecast is made of the prospects of taxonomic diversity as fast-growing ornamental long-lived woody plants. The taxonomic diversity of gymnosperms of the families Cupressaceae (4 genera) and Pinaceae (5 genera) in the collections of the Federal Scientific Center of Agroecology of the Russian Academy of Sciences is presented. Three varieties of the North American species of Pseudotsuga menziesii (Mirb.) Franco – var. viridis, glauca, caesia, which have been undergoing introduction tests since 1935 in chestnut soils. Purpose - to analyze the introduction tests of Pseudotsuga menziesii (Mirb.) Franco to predict the effectiveness of its use in the Lower Volga region. A comparative assessment of coniferous introducers in terms of growth rates is given. At the age of 70, the height of P. menziesii varieties varied from 12,8 (diameter 0,23 m) to 16,1 m (0,29 m) and surpassed Pinus sylvestris, Picea pungens and Larix sibirica in this indicator. An analysis of annual increments under conditions of chestnut soils indicates a culmination of growth at 7 years, on buried chestnut soils – 9 years. In other age groups, slight fluctuations in growth were noted, which indicates the drought resistance of the species. The advantage of P. menziesii var. viridis in terms of growth and condition (2,0-3,5 points). Taking into account the selected decorative elements and the duration of their impact and seasonal variability of aspects, landscape groups (decorativeness 260-367) with the participation of Pseudotsuga menziesii were developed to create or reconstruct green spaces.