川西南柳杉年轮宽度指数与气候变化的关系

【目的】树木年轮作为一种代用的气候资料有着重要的科学意义,探讨了柳杉年轮宽度指数与气候要素之间的关系,为气候变化是如何影响树木的生长过程研究提供一定的依据。【方法】以川西南40a柳杉为研究对象,采用ARIMA模型拟合柳杉(Cryptomeria fortune)的径向生长,同时建立川西南地区柳杉年轮宽度指数年表,利用多重对应分析(MCA)柳杉径向生长与气候要素之间的关系。【结果】柳杉年轮宽度指数的变化趋势与温度的变化趋势呈现"分离现象",与降水量的变化趋势一致;柳杉年轮宽度指数与当年生长季4、8月份温度呈显著相关关系(P<0.05),柳杉年轮宽度指数与上个生长季的降水量呈正相关关系,与当年生长季7月份降水量呈显著正相关(P<0.05),与上个生长季10月份及当年生长季6月份累计日照时间呈显著负相关关系(P<0.05);当年生长季6-8月份适宜的温度有利于年轮宽度的增加,当年生长季5-9月份的温度和降水量达到一定的指标时不利于年轮宽度的增加。【结论】温度、降水总量与柳杉年轮宽度指数总体关系密切,生长季6-8月份的温度、5-9月的降水总量对柳杉径向生长影响明显。

Cryptomeria Fortune Tree-ring Width Index with Responses to Climate Change in the Southwestern of Sichuan

【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.【Results】 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.Additionaly,radial growth is significantly affected by temperature from June to August and total precipitation from May to September.