Provenance tests for survival and growth of 50-year-old Japanese larch (Larix kaempferi) trees related to climatic conditions in central Japan

Survival and growth of Japanese larch (Larix kaempferi) from 25 provenances in the natural distributional range were examined at three test sites in central Japan. Climatic conditions of the sites and provenances indicated a contrast between northwest and southeast locations across the distributional range. Density, height, diameter, and crookedness of stems and width and length of branches were measured for 50-year-old trees, and per-area cross-sectional area and volume of stems were calculated. Variance components among the provenances were large in the stem area and volume (27–33 %) and the branch width (26 %); those among the sites were large in the stem height, diameter, and density (70–81 %); and those of interaction between sites and provenances were small (0–12 %) in all the variables. Principal component analyses showed that eastern provenances exhibited large size of stems and branches at most sites. Growth rate and maximum size at each site were estimated from fitting the stem volume at three ages (12, 31 or 32, and 50 years) to growth curves in logistic functions. Eastern provenances, where seasonal variation is least in temperature and most in precipitation, showed the highest performance of stem and branch growth. The findings from our long-term survey of the L. kaempferi provenance tests suggest climatic effects on survival and growth traits and potential provenances from which to select new breeding materials.