Abstract: The relationship between tree-width of Tetracentron sinense and climate factors in the humid evergreen broad-leaved forest in the middle Ailao Mountains was studied in order to explore the potential for reconstructing climate change in the past and to provide a theoretical basis for modelling species distribution and conservation of T. sinense in the context of global climate change.[Methods]Increment cores of T. sinense were collected by increment borer, and tree ring-width was measured with standard dendrochronological techniques. Each tree-ring measurement was assigned to the year of its formation with cross-dating techniques, and then tree-ring series were detrended with negative exponential curve and cubic spline function. The resulting standard chronology was correlated with monthly climatic data from Jingdong meteorological station.[Results] Analysis of tree ring-width chronology and climate factors showed that the radial growth of T. sinense was significantly correlated with mean temperature and extreme high temperature of February and June in the year (P<0.05). Moreover, ring-width chronology showed significant positive correlation with the number of hours of sunlight (P<0.05), but negative correlation with relative humidity of February and March (P<0.01). Our study demonstrated that multiple climatic factors influenced the radial growth, and the climatic conditions during the early growing season is crucial for the growth of T. sinense.[Conclusion] This study showed that T. sinense in the warm and humid subtropical forests produce distinct and cross-datable annual growth rings. Tree ring-width chronology of T. sinense can reveal considerable climate information, which has high potential for reconstructing past climate change in the study area.

Key words: Ailao Mountains, tree rings, Tetracentron sinense, climate factors, radial growth, temperature, precipitation