Comparison of traits between male sterile and fertile Cryptomeria japonica D. Don trees in selected stands

The physical characteristics of elected male sterile trees in Niigata Prefecture, tree height, diameter at breast height( DBH), basal bending, modulus of elasticity of tree trunk and types of snow damage, were compared with those of male fertile trees from eleven stands. The sampled stands were regarded as being typical of an unsuccessful plantation and exhibited potentially fatal examples of snow damage, including stem breakage, stem splitting and uprooting. Moreover, the stands sampled also had a lower average tree height, smaller DBH, and remarkably lower stand density than other C. japonica stands in the region. Interestingly, no marked differences were observed in any of the characters examined or in the extent of snow damage between male sterile and fertile trees. The results imply that the abnormalities exhibited by male sterile trees are restricted to pollen formation, and not to other characteristics such as growth, which is normal.