准噶尔盆地箭杆杨生长模型及生长进程动态分析

揭示树高、胸径和材积的动态变化过程，对掌握树木个体生长的基本规律和制定相应的抚育管理措施具有重要的现实意义。以准噶尔盆地防护林树种箭杆杨为研究对象, 运用树干解析法，对19 a生箭杆杨的树高、胸径、材积的生长规律进行调查研究。结果表明：箭杆杨的树高速生阶段集中在第3~14 a，胸径速生期为第2~19 a，材积速生期为第2~18 a。树高早期生长缓慢, 其速生期比胸径和材积晚，材积表现为早期速生。在胸径快速增长期间适当进行施肥管理，有利于培育优质大径材。箭杆杨成熟年龄在第27~30 a。建立的箭杆杨树高、胸径和材积生长的6种模型：幂函数型、二、三次多项式回归型、对数型、Logistic以及Richards方程均取得显著的拟合效果(P<0.01)，Richards方程是模拟箭杆杨树高、胸径和材积生长进程的最佳模型。

Growth Model and Process of Populus nigra var.thevestina in the Junggar Basin

Research on dynamic process of the growth of tree height, diameter at breast height (DBH) and timber volume of poplar plantation is of great significance in the further understanding of growth laws and establishing the corresponding foster and management measures. The whole growth process of 19 a-old Populus nigra var. thevestina plantation in the Junggar Basin, including the growth of tree height, DBH and timber volume, was studied using the trunk analysis method, and five models related to the growth of tree height, DBH and timber volume, including the power function type, quadratic and cubic polynomial regression model, Logistic model and Richards model, were developed and compared. The results showed that the rapid growth of tree height occurred at the 3-14 a-old trees, that of DBH at the 2-19 a-old ones, and that of timber volume at the 2-18 a-old ones. The rapid growth duration of tree height occurred later than that of DBH and timber volume, and timber volume grew rapidly at the early stage. The maturity age for the highest timber volume of P. nigra varied in a range of 27-30 a. The statistical significance of five models used to describe the growth of tree height, DBH and timber volume were all lower than 0.01, which means that all the five models were fitted well. Richards model was the optimal one to describe the growth process of tree height, DBH and timber volume of P. nigra, and their correlation coefficients were as high as 0.983, 0.999 and 0.998 respectively.