Title: Characterization Of Diameter Distribution Of Tectona Grandis (Linn. F.) Using Different Models In Attachi Forest Reserve, Delta State, Nigeria
Authors: Fadun, E. A. and Ureigho, U.N
Volume: 8
Issue: 11
Pages: 72-80
Publication Date: 2024/11/28
Abstract:
This study investigated the characterization of diameter distribution of Tectona grandis linn. F using different statistical models in order to identify the best-fitting model for the sustainable management of Attachi Forest Reserve, Delta State, Nigeria. Stratified random sampling technique was used to collect growth data from three age series (2017, 2019, and 2020 plantations). Based on the size of each plantation and availability of teak stands, 5 temporary sample plots of 20m x 20m (0.04ha) were randomly selected in each plantation. Complete enumeration was done in each sample plot and diameter at breast height (DBH) measured. Ten different models, including Weibull (3P), Gamma (3P), Johnson SB, Beta, Pareto, and the Wakeby distribution were applied for the diameter distribution characterization. Goodness-of-fit tests was used to test the suitability of the distribution models and Wakeby distribution model with values of Kolmogorov-Smirnov - 0.07426, Anderson-Darling - 0.93712, and Chi-squared - 22.927 was found to be the best-fit model followed by Gamma 3P distribution model (0.09776, 2.5255 and 39.275) and Weibull 3P distribution model (0.11578, 3.1875 and 49.696) with the least being Kumaraswamy distribution model (0.27481, 34.427 and no-fit in the Chi-squared test). Wakeby is therefore the best model for the characterization of Tectona grandis in the Attachi Forest Reserve. It has also shown to be the best distribution model for the sustainable management of Tectona grandis plantations in the study area, as it most accurately reflects the structural dynamics of the forest stand.