A comparative study on species composition and population dynamics characteristics of two Abies plants in the Pinaceae.

Abies plants within the Pinaceae family represent foundational species of coniferous forests in the Northern Hemisphere. To investigate the ecological adaptability and limitations of plantation forests in urban settings, this study conducted a comparative analysis of species composition and population characteristics between Abies holophylla and Abies nephrolepis in Changchun City, employing TWINSPAN classification, dynamic population indices, static life tables, time-series models, and survival functions. Key findings include: (1) A. holophylla and A. nephrolepis communities were dominated by Pinus sylvestris and Betula platyphylla, respectively; (2) A. holophylla exhibited a fusiform age structure dominated by mature individuals, while A. nephrolepis displayed an inverse-J-shaped structure with predominantly juvenile individuals; (3) Both populations showed positive values for the intrinsic dynamic index (Vpi) and disturbance-mediated dynamic index (V'pi), indicating current growth trends; (4) Survival curves aligned with the Deevey-II, with mortality primarily driven by stochastic external disturbances. The convergence of Pmax toward zero revealed low resilience to environmental perturbations. This study reveals functional degradation in urban plantation ecosystems, demonstrating that both Abies populations face recruitment failure risks and exhibit weakened resilience to environmental disturbances. To address these challenges, targeted interventions-including artificial replanting, microhabitat reconstruction, and thinning of competing tree species to promote regeneration-are critically required. These findings offer theoretical underpinnings for adaptive management strategies in urban forest conservation.