中文摘要：

基于2005年兴安落叶松（1969年造林）树干液流及其环境因子观测数据（30min频率）,采用错位分析方法对不同季节（春、夏、秋、冬季各20d）及全年树干液流时滞效应进行主成分分析和时滞矫正分析,探讨其综合影响.结果表明：不同季节、不同环境因子对兴安落叶松树干液流影响的时滞效应不同,光合有效辐射对树干液流的时滞影响集中在提前0.5～1h,气温和空气湿度集中在提前或滞后0～2h,土壤温度和土壤湿度的时滞时间较长或不能判定.当把基于短期数据（20d）获得的不同环境因子时滞时间用于全年数据的时滞校正时,并没有明显改变各因子与树干液流线性拟合方程的斜率和截距,甚至降低了决定系数,但对逐步回归方程各因子系数的影响明显且一致：时滞校正使空气湿度对树干液流的影响增强,但光合有效辐射、气温和土壤温度对树干液流的影响有所下降.使用主成分分析方法简化多个环境因子共同作用下的时滞效应,对5个环境因子提取第1、第2主成分（〉75%信息量）进行错位分析,发现冬季不存在时滞效应,其他季节2个主成分均存在1～1.5h的时滞时间（提前）.

英文摘要：

Based on the one-year（2005） observations with a frequency of half hour on the stem sap flow of Larix gmelinii plantation trees planted in 1969 and the related environmental factors air humidity（RH）,air temperature（Tair）,photosynthetic components active radiation（PAR）,soil temperature（Tsoil）,and soil moisture（TDR）,principal analysis（PCA） and correction analysis were made on the time lag effect of the stem flow in different seasons（26 days of each season） and in a year via dislocation analysis,with the complexity and its integrative effects of the time lags of environment factors affecting the stem sap flow approached.The results showed that in different seasons and for different environmental factors,the time lag effect varied obviously.In general,the time lag of PAR was 0.5-1 hour ahead of sap flow,that of Tair and RH was 0-2 hours ahead of or behind the sap flow,and the time lags of Tsoil and TDR were much longer or sometimes undetectable.Because of the complexity of the time lags,no evident improvements were observed in the linear correlations（R2,slope,and intercept） when the time lags based on short-term（20 days） data were used to correct the time lags based on whole year data.However,obvious improvements were found in the standardized and non-standardized correlation coefficients in stepwise multiple regressions,i.e.,the time lag corrections could improve the effects of RH,but decreased the effects of PAR,Tair,and Tsoil.PCA could be used to simplify the complexity.The first and the second principal components could stand for over 75% information of all the environmental factors in different seasons and in whole year.The time lags of both the first and the second principal components were 1-1.5 hours in advance of the sap flow,except in winter（no time lag effect）.