Responses to climate by tree-ring widths and maximum latewood densities of two Abies species at upper and lower altitudinal distribution limits in central Japan

摘要

This study examined the effects of climate on tree-ring widths and maximum latewood densities of Abies veitchii and Abies mariesii at the upper and lower distribution limits in central Japan. A. veitchii and A. mariesii dominated at the lower and upper parts of the subalpine zone, respectively. Residual chronologies of tree-ring width and maximum latewood density were developed for the two Abies species at the upper and lower distribution limits, and were compared with monthly mean temperatures and monthly sums of precipitation. Tree-ring widths of the two Abies species at the upper and lower distribution limits positively correlated with temperatures during the beginning of the dormant season and during the growing season of the current year, except for A. veitchii at the lower distribution limit, which showed no positive correlation with temperature. Maximum latewood densities of the two Abies species at the upper and lower distribution limits positively and negatively correlated with temperatures and precipitation, respectively, during the growing season of the current year. Therefore, tree-ring widths and maximum latewood densities of the two Abies species were sensitive to low temperature, except for the tree-ring width of A. veitchii at the lower distribution limit with the warmest thermal conditions along the altitude. Global warming is suggested to affect maximum latewood densities and tree-ring widths of the two Abies species along the altitude.