Home – Home – Jornals – Geography and Natural Resources 2022 number 4

This paper presents the results of long-term expeditions which were aimed to study the occurrence of natural hybrids between Siberian stone pine (Pinus sibirica Du Tour) and Siberian dwarf pine (P. pumila (Pall.) Regel)). It was found that the ranges of these species are the most extensive among the five-needle pines, and they are located mainly in northern Asia. The eastern part of the Siberian stone pine range and the western part of the Siberian dwarf pine range overlap. Where both species grow together and the conditions for their cross-pollination are favorable, hybrids F1 are formed. It is shown that hybrids do not withstand competition with upright trees in phytocenoses typical for Siberian stone pine and are often damaged by snow piling. In phytocenoses typical for Siberian dwarf pine, hybrids show good growth, but are damaged due to frost weathering. It was found that the most favorable locations for hybrids are open sunlit areas where they form a balanced symmetrical crown and have abundant cone-bearing, but such locations are scarce. It is shown that the hybrid zone is characterized by mosaic structure, and in the northeastern and southwestern parts hybridization transforms into introgression. In the northeastern part of the hybrid zone, which coincides with the northeastern border of the Siberian stone pine range, hybridization has led to the replacement of Siberian stone pine by cryptic hybrids with the morphology of this species and mitochondrial DNA of Siberian dwarf pine, which are obviously more adapted to local conditions. In addition, it was found that hybrids growing in the south of Tomsk oblast are resistant to local climate and pests to the same extent as are parental species, and their unusual crown form, intermediate relative to the species, allows us to consider hybrids as an additional source of plant material for use in breeding work.