Objective Mongolian Scots pine (Pinus sylvestris var. mongolica) is the predominant evergreen coniferous species introduced for afforestation in China's Three-North Shelterbelt Development Program. The objective of this study was to elucidate potential adaptive changes in reproductive strategies during the process of introduction and cultivation process from its natural distribution range to different afforestation areas.

Method Plantations located in Zhanggutai Town, Liaoning Province, and Yuyang District, Shaanxi Province, were selected as typical introduction sites, while a natural forest in Honghuaerji Town, Inner Mongolia, served as the reference site. Cones were collected from mother trees of different age groups across the three regions. Eleven cone and seed traits were measured and comparatively analyzed.

Result Significant regional and age-related variations were observed in the major cone and seed traits. Principal component analysis indicated that cone size, seed size, and seed quality accounted for more than 72% of the cumulative variance, indicating that these traits were most closely associated with reproductive capacity. At the juvenile and middle-aged stages, cones and seeds from Zhanggutai exhibited superior development, whereas at the mature stage, natural stands in Honghuaerji showed stronger reproductive performance, reflecting environment-driven adjustments in seed development characteristics. Reproductive strategies varied markedly among regions. In Zhanggutai, cone fresh mass, cone length, and seed wing length were highly positively correlated with reproductive capacity (p<0.001), suggesting a highly integrated strategy of multi-trait coordination. In Yulin, mean seed mass was significantly negatively correlated with the number of viable seeds (p<0.05), indicating an optimized resource allocation strategy favoring seed number under resource-limited conditions. In contrast, in Honghuaerji, cone basal length and short diameter were strongly correlated (r=0.994), suggesting that under favorable environmental conditions, reproductive performance was stabilized around seed plumpness and quality, forming a mature reproductive system.

Conclusion The pronounced regional and age-related variation in cone and seed traits highlights the strong adaptive capacity and strategic flexibility of Mongolian Scots pine in response to environmental heterogeneity.