Responses of radial growth of Pinus tabuliformis to climate change at the northern slopes of Qinling Mountains, China

A standard chronology (STD) was established with samples collected from Nanwutai at the northern slopes of the Qinling Mountains. The correlations between radial growth of and climatic factors were explored. The results showed that radial growth was positively correlated with moisture factors in previous September and current May. The radial growth was positively correlated with temperature factors in pre-vious November and negatively with that in previous October and current May. There was significant lag effect of climatic factors on the radial growth. The radial growth of was well correlated with the PDSI drought severity index, with positive correlations being identified from September to December of the previous year and in May of the current year. The regression model was able to simulate the relationship between STD and PDSI. The formations of extremely wide and narrow tree-ring were mainly a result of drought condition. Combined with climatic factors, PDSI could better reflect the radial growth charac