Home – Home – Jornals – Siberian Journal of Forest Science 2025 number 4

The results of 18-year observations of cone production in clones from latitudinal and longitudinal ecotypes of the Siberian stone pine ( Pinus sibirica Du Tour) on geographical crops in the south of Tomsk Oblast are presented. With age, the number of female cones increased in trees of all ecotypes, and the pattern of differences between ecotypes changed. At the age of 10 years, the northern ecotypes and one of the eastern ecotypes formed the greatest number of cones. After 8-10 years, the central ecotypes from both transects had the most abundant cone production. By the age of 28 years, the southern ecotype became the leader in the cone number among the latitudinal ones, and among the longitudinal ecotypes, the western, local, and one of the eastern ones differed insignificantly. This trend remained unchanged until the end of the observation period for the longitudinal ecotypes, and among the latitudinal ecotypes, by the same time, the southern ecotype became the leader. The Siberian stone pine ecotypes were characterized by periodicity of cone crops. The degree of cone retention in all Siberian pine ecotypes was closely related to the date of the last spring frost and the sum of effective temperatures accumulated by this date; no significant correlations were found with other weather factors. Dangerous late frost led to a complete or partial loss of cone crop in all ecotypes. The later the frost and the higher the accumulated sum of effective temperatures, the greater the damage to the cone crop. At this time, cones were preserved more often in northern ecotypes than in others.