树木年轮分析在环境变化研究中的应用

APPLICATION OF TREE RING ANALYSIS TO THE STUDY ON ENVIRONMENT VARIATION

鉴于环境变化与树木生长关系密切,可以通过对树木年轮变异状况的分析,获取环境变化的信息。本文概述了树木年轮分析的基本原理、研究途径以及已经取得的进展与应用前景。

Greater advances in dendrochronological study have been made since 1970's because of increased emphasis on research into environment variation and the obvious improvement of the computational techniques. According to a certain relationship between tree ring growth and environmental factor, the proxy data for reconstructing past environmental variation can be obtained by the tree ring series. As a branch of science, dendrochronology contains some basic principles and concepts, such as the uniformitarian principle, the principle of limiting factors, the concept of ecological site selection, the concept of sensitivity, the concept of crossdating and the concept of repetition. The essential strategy to study on environmental variation using tree ring analysis could be divided into three parts: sampling in field, establishing final tree ring chronology and reconstructing the history of environmental factor. Of course, there are some techniques in each part. As an effective approach to crossdating, the 'three-step dating' method has been emphasized. The three steps are: visual dating on the cores, skeleton plotting and computer dating check. Meanwhile, the response function and transfer function have been demonstrated with an example. The functions would provide an estimate of past change of local climate factors. Recently, a few branches of dendrochronology have been appeared with broad application prospects. Some issues in dendrochronology were mentioned in this paper. They are: reconstruction of past climate, densitometry analysis, stable isotopes or heavy metal elements in tree rings, tree ring analysis in warm-humidity areas, combining different proxy data and dendrogeological analysis. In brief, the dendrochronological work has been undergoing a widespread and profound development in the whole world, At the same time, dendrochronological analysis in China is likely to have a broad potential and will play a more important role in the study on environmental variation.