Mô hình phân bố tần suất đường kính và chiều cao lâm phần keo lá tràm (acacia auriculiformis) tại vùng cát ven biển huyện Lệ Thủy, tỉnh Quảng Bình

Abstract

The frequency distribution of stand diameter and height provides managers with crucial information to offer suitable and efficient solutions for managing forests for commercial purposes. In this study, 18 temporaty plots were established with an area of 500 m² (20m x 25 m) set up using to non-proportional stratified random sampling method for data collection of Acacia auriculiformis stands from 5 to 12 years old planted in the coastal sandy areas of Le Thuy district, Quang Binh province. The frequency distribution of diameter and height was modeled using the Maximum Likelihood Estimation and Kolmogorov-Smirnov standard . The percentage of trees concentrated in the diameter sizes D2 (4 - 6 cm), D3 (6 - 8 cm), and D4 (8 - 10 cm) was 34.3%, 32.0%, and 16.9%, respectively. These three diameters accounted for 83.1% of the total number of trees. The percentage of trees concentrated in the height sizes H1 (2 - 4 cm), H2 (4 - 6 cm) was 23.9% and 66,0%, respectively. These two height accounted for 89,9% of the total number of trees. The number of trees decreased as the diameter size (or height size) increased or decreased. The diameter distribution could be most accurately simulated by the Lognormal distribution, and the height distribution could be most accurately simulated by the Weibull distribution.