Construction And Simulation Of Stand Growth Model

Stand growth model is an important tool for the management of forest resources and harvest estimates. With the model, we can know the growth dynamics of trees timely, it is good to long-term forest management, planning and harvesting. In this paper, we choose the situation of tree growth in the city of Longquan, Zhejiang province as the background, and analyzes the natural geography and forest distribution in Longquan so as to determine the major forest types. Then we select the data of subcompartment in Longquan to establish model to analyse according to different types of forest.(1)By using these five stand growth models, Compertz、Korf、Logistic、Mischerlich、Schumacher, we try to simulate the unit volume of Chinese red pine and Chinese fir, then we find that before we consider stand density index, the absolute coefficient of all equations is less than 0.8. However, when we consider the coefficient of R2, MR, AMR, RAR, SR, we get the conclusion that Mischerlich is the best model for Chinese red pine and Korf is best for Chinese fir.(2)By using the Logistic equation, we simulate the average per unit volume in different age of Chinese red pine and Chinese fir, we discovered that when the coefficient of determination was more than 0.85, the fitting effect is good, what’s more, we also discovered that the fitting effect of Chinese fir is always better than Chinese red pine, its determination coefficient can reach 0.92. Besides, we establish model of the average unit volume grown in different sites, and find that all thedetermination coefficient is higher than 0.8, when the determination coefficient reach 0.96, the fitting effect is good.