The Relationship Between Radial Growth of 2 Conifer Trees and Climatic Factors in the Haba Snow Mountain

To study the relationship between tree radial growth and climates in the Haba Snow Mountain, Northwestern Yunnan, we collected tree-ring samples and established residual chronologies of Taxus yunnanensis and Pinus yunnanensis. Then we examined growth responses to climate variables by response function analysis and redundancy analysis to identify the key climatic factors driving the radial growth of the 2 species. The results showed that temperature and precipitation were both factors affecting the radial growth of the 2 species, with an obvious lag effect. Hydrothermal condition in the post growing season(September to October) of the last year was the key factor affecting the growth of T. yunnanensis. Temperature and precipitation of previous post-growing season positively and negatively affected its growth, respectively. The radial growth of P. yunnanensis was negatively affected by temperature of the previous August and current July, and showed a significantly positive correlation with precipitation of the current February, March and May. The redundancy analysis presented similar results as the response function analysis, further indicating that it can effectively quantify the correlation between the growth and climatic variables.