Abstract: Aims The variation patterns and correlations of leaf functional traits have always been a key aspect in unraveling how plants respond to climate change. However, the similarities and differences in the variation and correlation of leaf structural traits and photosynthetic physiological characteristics among different growth types of broadleaf plants remain unclear. Methods This study focused on 18 dominant or common broadleaf plants in a mixed broadleaved-Korean pine (Pinus koraiensis) forest. We measured four structural traits (leaf area (LA), leaf thickness (LT), leaf dry matter content (LDMC) and leaf mass per area (LMA)) and four photosynthetic physiological traits (chlorophyll value (SPAD), intercellular CO2 concentration (Ci), stomatal conductance (Gs) and net photosynthetic rate (Pn)). We analyzed the variation and correlations of leaf structural traits and photosynthetic physiological traits among different growth types of broadleaf plants. Important findings The variation range of leaf functional traits was between 7.73% and 74.54%. Inter-specific variation was the main source of variation for LA and LT, while growth type drived the variation in Ci, SPAD, LDMC, and LMA. Gs and Pn variation mainly originate from intra-specific variation. There were significant differences in leaf functional traits among different growth types. Specifically, herbs showed significantly higher LA, LT, and Ci compared to shrubs and trees, while trees exhibited significantly higher LMA, LDMC, SPAD, Pn, and Gs compared to both shrubs and herbs (p < 0.05). There was a significant isometric relationship between Pn and LMA, LDMC among different growth types, with slopes greater than 1, while SPAD with LA, LT, LDMC, LMA, Ci with LT, LDMC, LMA showed slopes less than 1, indicating allometric growth relationships. Herbs adopted a resource-acquisitive strategy, while relatively, trees adopted a resource-conservative strategy, shrubs adopt an intermediate strategy between trees and herbs, possibly linked to the light conditions in the environments inhabited by different growth types of plants. The study of the variation and interactions between leaf structural traits and photosynthetic physiological characteristics is crucial for understanding resource acquisition and allocation mechanism in plants.

Key words: functional trait, leaf photosynthetic characteristics, leaf structural traits, leaf economic spectrum