树轮年代学的若干进展

树轮年代学是一门研究树木木质部年生长层，以及利用年生长层来定年的科学。由于树轮不仅是一种定年工具，它本身还可提供树轮生成时的环境要素信息，为一种环境变化的代用资料。在全球变化特别是在过去全球气候变化研究中，树轮年代学受到愈来愈广泛的重视，在近期内取得了长足的、惊人的进展。本文仅在树轮长年表的建立，树轮年代学生物基础研究──模式研究，利用树轮对环境要素变化的研究，以及树轮的图像分析等几个与环境变化研究相关的方面和本学科目前研究热点的若干进展，予以概要的论述。

ADVANCEMENTS IN DENDROCHRONOLOGY

Dendrochronology is the science that deals with the dating and study of annual growth layers in wood. Since tree rings provide not only a method of dating, but also widespread, well - replicated, and annual dated proxy data for past environmental changes, dendrochronology has already contributed to many aspects of Past Global Changes (PAGES) research.During 1990' s, considerable progress has been made in dendrochronological and dendroclimatological studies in China. Well-replicated tree-ring metement cores from several conifer species have been collected in many places including the Qinlingshan Mountain, the Changbaishan Mountain, the Qilianshan Mountain, and the western Sichuan. After carefully cross-dating and measurement of each core, standard and residual ring-width chronologies have been developed according to chronology building procedure. Some of these residual chronologies have been used successfully to reconstruct the past climate. At present the longest ring-width chronology in dendroclimatic study from the northwest China lasts more than 1 000 years. The longest one from the central China is only about 500 years. However, the variance explained by the regression equation for climate reconstruction is up to 66% when the chronology is included in the reconstruction. There exists a strong relation between tree growth and climate factors, since sampling site is very close to the meteorological station where the climatic data are available.In addition to dendroclimatological study, the dendrochronological modeling and tree-ring image analysis have been performed recently in China. Although, these studies are still preliminary, it is sure that dendrochronology is growing vigorously in China.