Abstract
Cell deformation behavior of Japanese cedar (Cryptomeria japonica) and Japanese cypress (Chamaecyparis obtuse) were observed during progress in the radial compression using a scanning electron microscope (SEM). The deformation behavior were defferent between Japanese ceder and Japanese cypress. In Japanese ceder, the early wood cells close to the boundary of the annual ring did not buckle up to 55% of compressing ratio of the annual ring (CR), whereas those of Japanese cypress buckled at 32% of CR. This means the earlywood cells close to the boundary of annual ring of Japanese cypress buckled easier than those of Japanese cedar. The dimensional ratios in radial/tangential dimension (R/T) of uncompressed cells were measured from SEM images, and then were compared with the deformation pattern in each species. A significant correlation were found between CR when the cells buckled at the respective radial position in an annual ring and R/T of the cell at each position. From this, it can be concluded that the compressive deformation behavior of cells was related to the distribution of R/T of the cells in an annual ring.
