Abstract: Using a space-for-time substitution approach, we examined leaf traits, wood density, and growth rates of dominant woody species in the understory of Pinus massoniana forests at 10-, 20-30-, and 50-year restoration stages in the Guniujiang Nature Reserve, Anhui Province. We found that: (1) Plant functional traits varied significantly among restoration stages. Early-stage forests (10 years) were characterized by higher leaf nitrogen and phosphorus concentrations, higher growth rates, and lower wood density, whereas late-stage forests (50 years) exhibited longer leaf lifespans and higher wood density. (2) The co-occurring species Eurya muricata and Loropetalum chinense showed gradual increases in specific leaf area and decreases in leaf thickness across the restoration chronosequence. (3) The biomass increment of understory woody species was significantly positively correlated with leaf nitrogen content per unit mass (N_mass), leaf phosphorus content per unit mass (P_mass), total leaf nitrogen content (TN), and total leaf phosphorus content (TP), while the relative growth rate of basal diameter (RGB) was significantly negatively correlated with wood density. Together, these findings underscore the importance of functional trait dynamics of understory species during forest succession.

Key words: Pinus massoniana forest, evergreen broad-leaved forest, plant trait, ecological response