2026 Volume 34 Issue 2 Pages 19-25
Misao Yokoyama, Takao Itoh Timber Species Selection in the Motoyamaji Five-Story Pagoda : on the use of Koyamaki (Sciadopitys verticillata). Ap. For. Sci. This study investigates the rationale behind timber selection for the Five-Story Pagoda of Motoyamaji Temple (Mitoyo City，Kagawa)，a Tangible Cultural Property completed in 1910. During the “Great Heisei Repair” (2015–2019)，wood species identification was conducted on 108 structural members. Optical microscopy revealed that Koyamaki (Sciadopitys verticillata) was utilized not only for a section of the central pillar (shinbashira) but also for key structural components of the third story，including the shitenbashira (four inner pillars) and side pillars. Furthermore，the analysis uncovered a systematic，story-by-story differentiation of timber species among the primary pillars. These findings suggest that timber selection was not governed solely by mechanical properties. Instead，it reflected the broader social context of the Meiji period，including constraints and incentives introduced by forestry legislation，the preservation philosophy of the Ancient Shrines and Temples Preservation Law，and the religious symbolism associated with Mount Kōya. This study argues that the final selection represents a rational optimization，utilizing the highest quality timbers available within these institutional and cultural frameworks.
