马尾松胸径与根径和冠径的关系研究

利用在川渝地区进行的马尾松天然林标准地（含样木）调查资料，研究了马尾松根径（树干基部3个不同部位的直径d 0.00、d 0.05、d 0.10）与胸径（d 1.3）和冠径（Cw）的相关关系。结果表明，d 0.00与d 1.3、d 0.05与d 1.3、d 0.10与d1.3的相关关系模型都以二次抛物线回归方程为最优，且d 0.10与d 1.3的相关关系最为紧密；描述川渝地区马尾松天然林立木胸径与冠径关系的最佳回归模型为lnCw=-0.696 90+0.719 34lnd 1.3。该研究还编制了马尾松根径立木材积表，探讨了马尾松天然林的理论密度、最大密度和郁闭度为0.6～0.9时的适宜经营密度，对马尾松天然林的盗伐案件处理及经营管理有一定的参考价值。 

Relationship between DBH and ground diameter as well as crown diameter of Pinus massoniana

Based on the data from sample plots of Pinus massoniana natural forest in Sichuan and Chongqing areas,this paper studies the regression models of DBH and ground diameter (including d_0.00,d_0.05 and d_0.10),as well as crown diameter (C_w). The results showed that quadratic parabola regression function is the optimal one of d_0.00-d_1.3,d_0.05-d_1.3,d_0.10-d_1.3 and the relationship of d_0.00-d_1.3 is the tightest. The optimal regression model of DBH-C_w is lnC_w=-0.696 90 0.719 34 lnd_1.3. In addition,a ground diameter volume table of P. massoniana was established. And the theoretical density,maximum density and optimal management desity under a series of crown density between 0.6-0.9 were also discussed in this paper.