Geographical Features of Pinus sibirica Du Tour Renewal

Abstract

One of the main problems of forest ecology is to identify the patterns of the dynamics of natural populations of woody plants at the stage of their renewal, which programs the entire subsequent structure and development of plant ecosystems. The process of reforestation is determined by both the dynamics of seed production and the peculiarities of the seed distribution of forest-forming tree species. The renewal of five-needled pines of the Cembrae subsection with wingless seeds is due to their close trophic relationships with birds of the genus Nucifraga sp., which spread seeds, creating soil forage stocks. The purpose of this study is to reveal geographical features of the relationship between seed production and renewal of Siberian stone pine (Pinus sibirica Du Tour) with the intermediary participation of the thin-billed nutcracker (Nucifraga caryocatactes macrorhynchos Brehm C.L.). The research was carried out in 3 geographical regions of Pinus sibirica forests: in the forests of the Aldan Highlands in Southern Yakutia (59º40´ N., 125º24´ E.), the Northern Urals in the area of the Denezhkin Kamen mountain (60º25´ N., 59º32´ E.), and the Khamar-Daban Mountain range in the South-Eastern Baikal region (51º32´ N., 103º32´ E.). It is shown that each region of the Pinus sibirica growth differs in the dynamics of both seed production and renewal. It was found that the abundance of Pinus sibirica seedlings in the forests of the Aldan Highlands is positively associated (R2 = 0.46) with the yield of cones the previous year. The number of seedlings in the Northern Urals and Khamar-Daban is negatively related to the yield of cones of last year but is positively (R2 = 0.48–0.49) associated with the yield of cones of the year before last. We believe that seedlings in any case appear from the seeds of last year's yield. But the visible connection is due to the activity of the nutcracker. As a result of the stationary studies conducted in the Northern Urals, we identified a constant close (R2 = 0.81) positive relationship between the number of Pinus sibirica seedlings and the number of nutcrackers during the period of seed storage and dispersal in August-September of the previous year. It is assumed that the nature of the dynamics of seed production in the region affects the change in the number of nutcrackers during the seed harvesting period, which in turn determines the abundance of Pinus sibirica seedlings next year. This determines the revealed differences in the dynamics of Pinus sibirica renewal and its dependence on the yields of tree cones in the regions under consideration. © 2023, Northern Arctic Federal University named after M V Lomonosov. All rights reserved.