Abstract:

【Objective】:Dendroclirnatological approach has important significance in global climatic change and is regarded as a very good reference to climate factors．The aim of this study was to examine the relationship between tree-ring width index of Cryptomeria fortune and climatic factors. 【Method】: ARIMA model was employed to estimate the radial growth of C. fortune. Moreover, the tree-ring width index chronology of C. fortune in SW Sichuan was established. Multiple correspondence analysis (MCA) was used to analyze the relationship between radial growth and climates. 【Result】: The results showed a separation phenomenon between tree-ring width index and temperature change but tree-ring index increased with precipitation. The tree-ring width index of C. fortune was correlated significantly with the mean monthly temperature of April and August (p<0.05). Similar relationships were found in precipitation of last growing season, especially for  precipitation in July (p<0.05). Nevertheless, tree-ring width index was negetively correlated with accumulative total sunshine time of current June (p<0.05) and October of last growing season (p<0.05). The temperature of current growing season (from June to August) was beneficial to increase tree-ring width. However, when the temperature and precipitation of growing season (from May to September) exceeded the threshold, they were conducive to the increase of tree-ring width. 【Conclusion】: Temperature, total precipitation are related closely to tree-ring width index of C. fortune. Additiaonaly, radial growth is significantly affected by temperature from June to August and total precipitation from May to September.