THE EFFECT OF CLIMATIC FACTORS ON THE RADIAL GROWTH OF JAPANESE ASH IN NORTHERN HOKKAIDO, JAPAN

The influence of climate on the radial growth of Japanese ash (Fraxinu s mandshurica Rupr, var, japonica Maxim.) in northern Hokkaido. japan, was investigated. Fifteen trees were selected and ring widths were me asured. Standardization and autoregressive modeling were applied to th e series of ring widths for isolation of the climatic signal. A respon se function was calculated for the relationship between residual chron ology and monthly temperature and precipitation, In the season that pr eceded the growth, December precipitation is negatively correlated wit h ring width. During the growing season, May temperature is negatively correlated with ring width, while both temperature and precipitation in July are positively correlated with ring width. Tile results reveal the potential usefulness of Japanese ash for reconstruction of past c limate in Hokkaido, The chronology of Japanese ash contributes to a de velopment of a tree-ring network in Japan that is still sparse.