呼伦贝尔沙地樟子松径向生长特征的VS模型模拟分析

利用Vaganov-Shashkin模型对呼伦贝尔地区4个样点的沙地樟子松标准化宽度年表进行模拟研究,在2000年以前时段拟合度较好,而2000年以后时段拟合度较差。进而选取2000年以前的模拟结果进行径向生长过程分析。结果表明: 呼伦贝尔沙地樟子松主要的生长季为每年的5—9月,温度对每年樟子松生长初期与末期具有显著影响,而在树木生长季旺盛期,土壤湿度的不足是制约树木生长的主要因素。极端窄年树木径向生长速率受土壤湿度的影响较极端宽年明显,生长季中期7—8月树木径向生长速率在宽窄年份均呈降低趋势,表明该时期沙地樟子松生长均受到不同程度的干旱胁迫。研究结果与我国半干旱地区树木年轮生理模型分析特征相符,模型对呼伦贝尔沙地樟子松径向生长模拟具有一定的适用性。

Simulation analysis of the radial growth characteristics of Pinus sylvestris var. mongolica in Hulunbuir Sandy Land by Vaganov-Shashkin Model

The Vaganov-Shashkin model was used to simulate the standardized ring-width chrono-logy of Pinus sylvestris var. mongolica 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 P. sylvestris var. mongolica in Hulunbuir Sandy Land was from May to September each year. Temperature had a significant impact on the early and late growth of P. sylvestris var. mongo-lica. In the prosperous period of the growing season, insufficient soil moisture was the main factor restricting the radial growth. The radial growth rates of P. sylvestris var. mongolica 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 P. sylvestris var. mongolica 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 P. sylvestris var. mongolica in Hulunbuir Sandy Land.