观光木人工林单木胸径树高生长模型研究

The Study on Growing Models for DBH and Height of Individual Tree in Michelia odora Plantations

为研究观光木林分生长量和林木生长规律,以期为该树种人工林的科学经营和可持续发展提供参考、依据。以赣南树木园36年生观光木人工林为研究对象,通过树干解析,对其胸径、树高、材积等生长规律进行分析,采用线性方程、对数方程、二次方程、三次方程、乘幂式曲线方程和S曲线方程6个数学模型进行回归和分析比较。研究结果表明,树高、胸径基本呈现较为平稳的增长态势,其连年生长量均有波动性,胸径平均生长量随着林龄的增大而减小,但其下降速度较为缓慢,树高平均年生长量逐年上升,但其增幅相对缓慢。通过分析比较发现,观光木基于胸径的最优树高生长模型为三次方程,其最优生长曲线方程为Y=0.001x^(3)-0.093x^(2)+2.447x-3.38,拟合精度较高,该模型可实现观光木人工林林分树高的有效估测。

The purpose of this research is to study the growth law of the Michelia odora and to pro-vide a reference for the scientific management and sustainable development of the artificial forest ofM.odora.Taking the 36-year-old M.odora plantation in Gannan Arboretum as the research ob-ject,the growth of its DBH,tree height and volume were analyzed through stem analysis.Based on the mathematical models including linear equation,logarithmic equation,quadratic equation,cubic equation,power curve equation and S-curve equation,the regression analysis and comparison with each other were made.The tree height and DBH showed a relatively stable growth trend,and their annual growth was fluctuating.The average growth of DBH decreased with the increase of forest age,but its rate was relatively slow.The average annual growth of tree height increased year by year,and its growth rate was relatively slow.Through analysis and comparison,the optimal tree height growth model based on DBH was found to be the cubic equation,and its optimal growth curve equation was Y=0.001x^(3)-0.093x^(2)+2.447x-3.38,with the highest fitting accuracy.This model can achieve an effec-tive estimation of the tree height of the Michelia odora plantation through the determination of DBH.