BANGLADESH JOURNAL OF FOREST SCIENCE
A Half-yearly Peer Reviewed Journal of Bangladesh Forest Research Institute
A Half-yearly Peer Reviewed Journal of Bangladesh Forest Research Institute
Keora (Sonneratia apetala Buch.-Ham.) is one of the most important tree species for large scale plantations in the coastal areas of Bangladesh. The aim of this study was to generate a common volume equation and table for predicting the total and merchantable volume of planted and natural stand of S. apetala in the coastal areas of Bangladesh. A total of 430 sample trees having different girth classes were sampled from the plantation stands of Chattogram, Noakhali, Bhola and Patuakhali. Twenty one (21) models were tested to derive best-fit models for the volume over bark and under bark. The best fit models were selected based on the highest value of R2 (co-efficient of determination), the lowest value of Akaike Information Criterion (AIC) and Root Mean Square Error (RMSE). The selected models were validated by Chi-square test of goodness of fit, Paired t-test, Percent Absolute Deviation (% AD) and 45 degree line test. The best-fit one-variable and two-variable basic models were and respectively. The best-fit models showed the highest efficiency in volume estimation compared to previous developed model in terms of Model Prediction Error (MPE), Model Efficiency (ME) and Root Mean Square Error (RMSE).
Jarul (Lagerstroemia speciosa L. Pers., Family- Lythraceae) is a semi-deciduous medium to large-sized tree with fluted bole, small buttress and slightly flaky bark tropical flowering tree species. It is a common ornamental tree planted along roadsides, gardens and parks in Bangladesh. The main aim of this study is to develop mathematical models for total volume estimation of jarul. To meet the quest we have tested 21 models for volume equation by regression technique. The best-fitted model for studied species have been selected by highest value of R2 (coefficients of determination), the lowest value of Akaike Information Criterion (AIC) and Root Mean Square Error (RMSE). The selected models also validated by Chi-square test of goodness of fit, Paired t-test, Percent Absolute Deviation (%AD) and 45 degree line test. The study appearance that, for one way analyses the model ln (V) = a+b ln (D) and for two way analyses ln (V)= a+b ln (D)+c ln (H) appeared to the best model for estimating the standing tree volume of jarul. Conversion factors equation has been determined to estimate under bark volume and under bark volume of different top end girth of 30, 35, 40 and 45 centimeters from these models. The best-fit volume model showed the highest efficiency in volume estimation compared to previous developed volume model of this species in terms of Model Prediction Error (MPE), Model Efficiency (ME) and Root Mean Square Error (RMSE).
Welcome to the Bangladesh Journal of Forest Science (BJFS) – a leading platform for advancing the knowledge and understanding of forest science in Bangladesh and beyond. Established with a commitment to excellence, BJFS serves as a cornerstone for researchers, practitioners, and enthusiasts dedicated to the sustainable management and conservation of forest ecosystems.
