关键词: 年轮年表, 敏感度, 气候变化, 横断山区

Abstract: The Hengduan Mountain area Lies in Southwest China, including Parts of East Tibet, West Sichuan and Northwest Yunnan, and has a varied topogra-phy.The average altitude of it is over 3,000m a.s.l, The climatic change during Historical Time in this area has not been studied because of the lack of data.By field investigation, the authors have got a large quantity of tree ring specimens in the area. After preliminary dating and necessary dendrochro-nological processing, twelve standardized deadrochronologies have been built Baaed on these chronologies, two curves including the fluctuations of the air temperature and the annual precipitation during the last hundreds of years in the mountain area were drawn,Some significant cold/warm and dry/wet periods could be divided also.A combined analysis between dendrochronologies and historical literature data which have five classes could help us to understand the successive variations of each climatic pattern since 1600 A.D. In addition the amplitude and periodicity of climatic change in the area have been calculated in this paper.It is obvious that the chief characteristies oi the modern climatic change in Kengduan Mountains might be concluded as follows.1)The temperature fluctuation during the last four hundred years in the area is similar to that in Tibetan Plateau, and the coldest period occurred in the first half of the 17th century.2)The long-term oscillation of precipitation is more obvious than that of air temperature.3) The statistical feature in the present century is, on the average, lower temperature and lower precipitation, but the climate pattern with high temperature and low precipitation has been increasing since 1950's,4)The amplitude of climatic variation in the area is smaller than tha t in Tibet or in the plain area located on the east of Tibet Plateau.5)By carrying out analysis on various series, some periodicities have been found, such as "quasi two year pulse", s. 6 years, 35 years and so on.

Key words: Dendrochronology, Sensitivity, Climatic Change, Hengduan Mountain