[Simulation analysis of the radial growth characteristics of var. in Hulunbuir Sandy Land by Vaganov-Shashkin Model].

The Vaganov-Shashkin model was used to simulate the standardized ring-width chrono-logy of var. on the sandy land in Hulunbuir. The results showed that the fitting degree was better in the period before 2000 than that after 2000. Thus, the simulation results before 2000 were selected to analyze the radial growth. The results showed that the main growing season of var. in Hulunbuir Sandy Land was from May to September each year. Temperature had a significant impact on the early and late growth of var. . In the prosperous period of the growing season, insufficient soil moisture was the main factor restricting the radial growth. The radial growth rates of var. in extremely narrow years were more limited by soil moisture than that in extremely wide years. The radial growth rates in the middle of the growing season (from July to August) showed a decreasing trend in wide and narrow years, indicating that the growth of var. was affected by drought stress. Our results were consistent with the characteristics of tree-ring physiological models in semi-arid areas of China. The model was applicable to the radial growth simulation of var. in Hulunbuir Sandy Land.