Advantages and disadvantages of planting seedlings and cuttings vary with environments: Japanese cedar seedlings achieve greater growth and survival rates but inferior stem forms than cuttings

Abstract

When selecting clonal forestry or seedling forestry, understanding of the growth and survival characteristics of cuttings and seedlings are important. However, there is still limited information about the generality of the differences between cuttings and seedlings over time, and it is still unclear whether their performance will change differently along environmental variations such as temperature, precipitation and snowfall. The present study evaluated the tree growth, survival and stem forms of C. japonica at 29 test sites exhibiting various environmental conditions, and compared the performance of cuttings versus seedlings. The seedlings substantially outperformed the cuttings in terms of survival rates and height and diameter growth, while the cuttings showed better stem form. The stand mean height and diameter was markedly larger at the warmer environments, while the mean survival rate was smaller at the sites with deeper snow. In younger planted trees, seedlings outgrew cuttings at the sites with better growth conditions in terms of taller stand mean height, which was also positively correlated with higher mean temperatures. Seedlings had a higher survival rate than cuttings at the heavier snow sites when the planted trees grow older. Future climate change scenarios predict that mean temperature will increase, and this situation would favor seedling forestry rather than cutting forestry for C. japonica. The approaches and insights from this study will be useful for selecting between clonal and seedling forestry for future climate changes.