Experience in the introduction of conifers in dry steppe conditions

Abstract

In the Volgograd region, J. sabina L. is the only native representative of coniferous woody plants; the existence of a population of one representative of conifers indicates the homogeneity of the dendroflora, which can lead to the destruction of the ecosystem as a whole. Plant introduction as a tool towards achieving dendroflora biodiversity is the most practical and promising method in dry steppe conditions. The aim of the study was to conduct a bioecological assessment and the life state of coniferous woody plants, as well as to determine the degree of introduction resistance in dry steppe conditions. An assessment of six introduced woody plants in the dendrocollections of the Federal Research Center of Agroecology of the Russian Academy of Sciences was carried out: Juniperus virginiana L., J. communis L., J. sabina L., Thuja occidentalis L, Platycladus orientalis (L.) Franco, Pseudotsuga menziesii (Milb) Franco. The timing of the onset and duration of the main phenological phases were determined by the method of phenological observations of GBS. With a deviation of the average annual air temperature above the norm by 1.05 ºС and the annual precipitation amount of 75% of the norm, the duration of the manifestation of the growing season was 58 days in J. sabina L., the shortest period in J. communis L. - 41 days, Pseudotsuga menziesii (Milb) Franco 55 days, J. virgiana L. - 56 days, T. occidentalis L. - 71 days, P. orientalis (L.) Franco - 68 days. As part of the ecological and biological assessment, such indicators as winter hardiness, drought resistance, the nature of dusting and seed production were investigated. Seed material was studied separately by the method of determining the mass of 1000 seeds. Also, an assessment was given of decorativeness, which determined the specificity of the use of a particular type for landscaping purposes. As a result of the studies, the values ​​of the acclimatization number were calculated for each species, according to which the degree of introduction resistance in dry steppe conditions was determined. In the course of the work done, practical recommendations were given for planting coniferous trees and shrubs for landscaping purposes.