ADVANCEMENTS IN DENDROCHRONOLOGY
树轮年代学的若干进展

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.