Intraspecific variation in growth-related traits-from leaf to whole-tree-in three provenances of Cryptomeria japonica canopy trees grown in a common garden

To elucidate the physiological and morphological factors underlying intraspecific variation in growth rate, we examined the variation in leaf and whole-tree traits for three geographical variations of ca. 45-year-old Japanese cedar (Cryptomeria japonica D. Don) with contrasting heights and radial growth in a common garden. Traits that reflect leaf-level photosynthesis, water relations, and whole-tree level crown structure in relation to light use and hydraulic architecture were measured. Overall, intraspecific variation in growth characteristics in field-grown adult trees was regulated by whole-tree properties rather than leaf properties. Most leaf traits were similar among provenances. Nevertheless, the leaf traits exhibited highest maximum net photosynthetic rate, dark respiration rate, and light compensation point in provenances whose native habitats are most similar to the common garden in the present study. Together with previous reports that this provenance has higher root nutrient acquisition capacity than the other two provenances, it can be said that organ-level resource use strategies are coupled in a tandem manner. At the whole-tree level, hydraulic architecture-as explained by axial variation in the hydraulically weighted tracheid diameter-can be linked to leaf distribution with respect to light use strategies as well as water transport capacity, leading to differences in growth characteristics among provenances. The study of intraspecific variation in growth characteristics in trees with a wide range of native habitats is expected to be a useful indicator for predicting changes in growth potential and forest dynamics in response to climate change in each habitat.