Abstract: Secondary succession following anthropogenic disturbance is widespread in temperate mixed conifer–broadleaf forests. The associated shifts in plant nutrient allocation strategies are a crucial component of secondary succession and may provide useful insights for ecological restoration, but they remain poorly understood. Here, we applied a 100-year chronosequence following historical selective logging across seven successional stages in northeastern China to measure carbon (C), nitrogen (N), and phosphorus (P) concentrations in the plants’ leaves, stems, and roots across 391 species-site combinations. During the early to mid-stages of secondary succession, C:N ratios declined, whereas N:P and C:P ratios increased. In the late successional stage, C:N:P tended to be stable, thereby suggesting a shift toward more conservative plant growth strategies. Moreover, inter-organ N allocation relationships shifted from near-isometric to allometric patterns, indicating enhanced stoichiometric differentiation among organs and providing stoichiometric evidence consistent with the predictions of our proposed Dynamic Coordination–Specialization hypothesis. Throughout the successional trajectory, phylogenetic effects consistently outweighed soil and other factors, consequently driving organ-specific shifts in stoichiometry. Our findings highlight shifts in plant adaptive strategies during secondary succession from the perspective of ecological stoichiometry and provide useful insights for forest restoration and nutrient management in temperate forests.

Key words: Ecological stoichiometry, Nutrient allocation, Secondary succession, Resource utilization strategy, Forest management