Abstract: 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.

Key words: font-family: 宋体, mso-bidi-font-family: 宋体, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, Populus nigra var. thevestina')">mso-bidi-language: AR-SA">Populus nigra var. thevestina, ')">growth, ')">growth model, ')">rapid growth age, Junggar Basin