Leaf functional traits vary along ontogenetic stages due to the corresponding changes in internal and external factors such as requirement, allocation and availability for resources and herbivory impact. In a well-developed forest, availabilities in light and water, and herbivory impact vary from forest floor to canopy, which could affect leaf traits related to resource acquisition and defense. Such ontogenetic changes should affect linkages between plant traits and performance, but it is unclear how such functional traits and diversity vary along ontogeny, particularly across diverse co-occurring species.
In this study, we measured LMA, leaf area, leaf strength, and defensive chemicals for seedling, sapling, and adult stages over 45 co-occurring woody species in a Japanese temperate forest. We found that LMA and leaf strength were generally higher at adult than sapling or seedling across species. Defensive chemicals, such as total phenolics and condensed tannins, were also generally higher at adult than sapling or seedling. On the other hand, lignin concentration was higher at sapling than at adult. The association among studied functional traits were not largely different between the stages. We will also discuss the ontogenetic variation in functional diversity of the assemblage.