样条函数拟合在年轮气候学分析中的可适用性

在树木年轮气候学分析中,应消除树木生长受遗传因子控制的缓慢生长趋势,进行生长量订正,使得年轮宽度序列转变成表征局地气候变化的指数序列。目前,最为广泛采用的是带尾的指数函数拟合方法,这在我国许多典型取样环境的年轮分析中,亦被证实是十分有效的。随着树木年轮取样的多样化,对非典型取样环境的样本,则必须采用较复杂的、多种函数形式进行订正,样条函数为其中之一。样条函数方法的应用现仍有争议,尤其是它的可适用性尚待更多资料论证。本文根据我国年轮样

THE APPLICABILITY OF SPLINE FUNCTION FITTING IN DENDROCLIMATOLOGICAL ANALYSIS

Based on some tree-ring specimens from a site where the environment is not typical for classical sampling, the smoothing spline is adopted and its applicability is described in this paper. In fact,it is an effective approach removing the non-climatic variance of some tree-ring width series while the growing trend apprears as non-exponential pattern, such as "U" curve,sine curve and straight line,etc.